v Cancer of the Esophagus

Introduction

The diagnosis of cancer of the esophagus brings with it many questions and a need for clear, understandable answers. This chapter provides information about the symptoms, diagnosis, and treatment of cancer of the esophagus, and it describes some of the possible causes (risk factors) of this disease. Having this important information may make it easier for patients and their families to handle the challenges they face.

The Esophagus The esophagus is a hollow tube that carries food and liquids from the throat to the stomach. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of the esophagus produce mucus, which keeps the passageway moist and makes swallowing easier. The esophagus is located just behind the trachea (windpipe). In an adult, the esophagus is about 10 inches long. Understanding the Cancer Process Cancer is a disease that affects cells, the body’s basic unit of life. To understand any type of cancer, it is helpful to know about normal cells and what happens when they become cancerous. The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells when they are needed.

This process keeps the body healthy and functioning properly. Sometimes, however, cells keep dividing when new cells are not needed. The mass of extra cells forms a growth or tumor. Tumors can be benign or malignant.

Cancer that begins in the esophagus (also called esophageal cancer) is divided into two major types, squamous cell carcinoma and adenocarcinoma, depending on the type of cells that are malignant. Squamous cell carcinomas arise in squamous cells that line the esophagus. These cancers usually occur in the upper and middle part of the esophagus. Adenocarcinomas usually develop in the glandular tissue in the lower part of the esophagus. The treatment is similar for both types of esophageal cancer.

If the cancer spreads outside the esophagus, it often goes to the lymph nodes first. (Lymph nodes are small, bean-shaped structures that are part of the body’s immune system.) Esophageal cancer can also spread to almost any other part of the body, including the liver, lungs, brain, and bones.

Risk Factors

The exact causes of cancer of the esophagus are not known. However, studies show that any of the following factors can increase the risk of developing esophageal cancer:

Having any of these risk factors increases the likelihood that a person will develop esophageal cancer. Still, most people with one or even several of these factors do not get the disease. And most people who do get esophageal cancer have none of the known risk factors.

Identifying factors that increase a person’s chances of developing esophageal cancer is the first step toward preventing the disease. We already know that the best ways to prevent this type of cancer are to quit (or never start) smoking cigarettes or using smokeless tobacco and to drink alcohol only in moderation. Researchers continue to study the causes of esophageal cancer and to search for other ways to prevent it. For example, they are exploring the possibility that increasing one’s intake of fruits and vegetables, especially raw ones, may reduce the risk of this disease.

Researchers are also studying ways to reduce the risk of esophageal cancer for people with Barrett’s esophagus.

Recognizing Symptoms

Early esophageal cancer usually does not cause symptoms. However, as the cancer grows, symptoms may include:

These symptoms may be caused by esophageal cancer or by other conditions. It is important to check with a doctor.

Diagnosing Esophageal Cancer

Esophageal cancer usually presents with difficulty in swallowing often associated with chest pain. Symptoms generally progress rapidly, and the disease is fatal in almost 95 percent of cases. The initial inability to swallow solids such as meat or bread is followed by difficulty in swallowing ground food and finally by difficulty in swallowing liquids. Malnutrition and weight loss are often profound. Obstruction of the esophagus may cause aspiration of food and pneumonia. Occasionally invasion of the esophageal tumor into the mediastinum produces mediastinal abscess formation, erosion into major blood vessels with massive bleeding, or erosion into bronchi with aspiration. 

The characteristic course of esophageal cancer makes diagnosis by the clinical history alone accurate in the advanced stage of this disease. A barium swallow will often confirm the clinical diagnosis by showing a highly specific finding of partial obstruction to the flow of barium by an intraluminal mass with sharp shelf like borders. Other kinds of tumors–lymphomas, sarcomas, and metastatic lesions–are uncommon in the esophagus and rarely present with a clinical history and radiologic pattern suggesting esophageal cancer. The diagnosis of esophageal cancer is proven by direct biopsy or by brushing of the tumor through an endoscope followed by histology or cytology or by intubation and lavage of the esophagus followed by cytology.

To help find the cause of symptoms, the doctor evaluates a person’s medical history and performs a physical exam. The doctor usually orders a chest x-ray and other diagnostic tests. These tests may include the following:

Staging the Disease

If the diagnosis is esophageal cancer, the doctor needs to learn the stage (or extent) of disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to what parts of the body. Knowing the stage of the disease helps the doctor plan treatment. Listed below are descriptions of the four stages of esophageal cancer.

Some tests used to determine whether the cancer has spread include:

Treatment and Prognosis

Esophageal cancer is treated by surgery, radiation therapy, or a combination of surgery and radiation. Unfortunately, there are no randomized controlled studies of these treatments. There are no studies comparing treatment with surgery or radiation with no treatment at all. Published reports do not show the superiority of one form of therapy over others. Tumors lower in the esophagus, tumors shorter in length, and tumors in women tend to do better with surgery.
Radiation therapy is usually reserved for patients who are ineligible for surgery.

The survival rates for adenocarcinoma of the esophagus are similar to survival rates for squamous cell carcinoma. Surgery is the preferred treatment, but radiation therapy is reported to be effective as well.

Although there are reports suggesting that better surgical techniques can improve survival from esophageal cancer, it is unlikely that the problem of esophageal cancer in the United States will soon be substantially affected by developing better methods of treatment. At present, the best hope for progress in reducing mortality from esophageal cancer is in better understanding of risk factors and their reduction in the population.

Treatment for esophageal cancer depends on a number of factors, including the size, location, and extent of the tumor, and the general health of the patient. Patients are often treated by a team of specialists, which may include a gastroenterologist (a doctor who specializes in diagnosing and treating disorders of the digestive system), surgeon (a doctor who specializes in removing or repairing parts of the body), medical oncologist (a doctor who specializes in treating cancer), and radiation oncologist (a doctor who specializes in using radiation to treat cancer). Because cancer treatment may make the mouth sensitive and at risk for infection, doctors often advise patients with esophageal cancer to see a dentist for a dental exam and treatment before cancer treatment begins.

Many different treatments and combinations of treatments may be used to control the cancer and/or to improve the patient’s quality of life by reducing symptoms.

Clinical trials (research studies) to evaluate new ways to treat cancer are an important option for many patients with esophageal cancer. In some studies, all patients receive the new treatment. In others, doctors compare different therapies by giving the new treatment to one group of patients and the usual (standard) therapy to another group. Through research, doctors learn new, more effective ways to treat cancer. More information about research studies can be found in the NCI publication Taking Part in Clinical Trials: What Cancer Patients Need To Know. NCI’s Web site has a section on clinical trials at http://cancer.gov/clinical_trials. This section provides general information about clinical trials and detailed information about specific ongoing studies. This information is also available from the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). For deaf and hard of hearing callers with TTY equipment, the number is 1-800-332-8615.

Side Effects of Treatment

The side effects of cancer treatment depend on the type of treatment and may be different for each person. Doctors and nurses can explain the possible side effects of treatment, and they can suggest ways to help relieve symptoms that may occur during and after treatment.
 

•	Surgery for esophageal cancer may cause short-term pain and tenderness in the area of the operation, but this discomfort or pain can be controlled with medicine. Patients are taught special breathing and coughing exercises to keep their lungs clear.
•	Radiation therapy affects normal as well as cancerous cells. Side effects of radiation therapy depend mainly on the dose and the part of the body that is treated. Common side effects of radiation therapy to the esophagus are a dry, sore mouth and throat; difficulty swallowing; swelling of the mouth and gums; dental cavities; fatigue; skin changes at the site of treatment; and loss of appetite.
•	Chemotherapy, like radiation therapy, affects normal as well as cancerous cells. Side effects depend largely on the specific drugs and the dose (amount of drug administered). Common side effects of chemotherapy include nausea and vomiting, poor appetite, hair loss, skin rash and itching, mouth and lip sores, diarrhea, and fatigue. These side effects generally go away gradually during the recovery periods between treatments or after treatment is over.
•	Laser therapy can cause short-term pain where the treatment was given, but this discomfort can be controlled with medicine.
•	Photodynamic therapy makes the skin and eyes highly sensitive to light for 6 weeks or more after treatment. Other temporary side effects of PDT may include coughing, trouble swallowing, abdominal pain, and painful breathing or shortness of breath.

Radiation Therapy and You, Chemotherapy and You, and Pain Control: A Guide for People with Cancer and Their Families are useful NCI booklets that suggest ways for patients to cope with the side effects they experience during and after cancer treatment.

Nutrition for Cancer Patients

Eating well during cancer treatment means getting enough calories and protein to control weight loss and maintain strength. Eating well often helps people with cancer feel better and have more energy.

However, many people with esophageal cancer find it hard to eat well because they have difficulty swallowing. Patients may not feel like eating if they are uncomfortable or tired. Also, the common side effects of treatment, such as poor appetite, nausea, vomiting, dry mouth, or mouth sores, can make eating difficult. Foods may taste different.

After surgery, patients may receive nutrients directly into a vein. (This way of getting nourishment into the body is called an IV.) Some may need a feeding tube (a flexible plastic tube that is passed through the nose to the stomach or through the mouth to the stomach) until they are able to eat on their own.

Patients with esophageal cancer are usually encouraged to eat several small meals and snacks throughout the day, rather than try to eat three large meals. When swallowing is difficult, many patients can still manage soft, bland foods moistened with sauces or gravies. Puddings, ice cream, and soups are nourishing and are usually easy to swallow. It may be helpful to use a blender to process solid foods. The doctor, dietitian, nutritionist, or other health care provider can advise patients about these and other ways to maintain a healthy diet.

Patients and their families may want to read the National Cancer Institute booklet Eating Hints for Cancer Patients, which contains many useful suggestions and recipes.

The Importance of Follow-up Care

Follow-up care after treatment for esophageal cancer is important to ensure that any changes in health are found. If the cancer returns or progresses or if a new cancer develops, it can be treated as soon as possible. Checkups may include physical exams, x-rays, or lab tests. Between scheduled appointments, patients should report any health problems to their doctor as soon as they appear.

Providing Emotional Support

Living with a serious disease is challenging. Apart from having to cope with the physical and medical challenges, people with cancer face many worries, feelings, and concerns that can make life difficult. They may find they need help coping with the emotional as well as the practical aspects of their disease. In fact, attention to the emotional burden of having cancer is often a part of a patient’s treatment plan. The support of the health care team (doctors, nurses, social workers), support groups, and patient-to-patient networks can help people feel less isolated and distressed, and improve the quality of their lives. Cancer support groups provide a setting in which cancer patients can talk about living with cancer with others who may be having similar experiences. Patients may want to speak to a member of their health care team about finding a support group. Many also find useful information in NCI fact sheets and booklets, including Taking Time and Facing Forward.

Questions for Your Doctor

This booklet is designed to help you get information you need from your doctor so that you can make informed decisions about your health care. In addition, asking your doctor the following questions will help you further understand your condition. To help you remember what the doctor says, you may take notes or ask whether you may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor–to take part in the discussion, to take notes, or just to listen.

Diagnosis
 

•	What tests can diagnose esophageal cancer? Are they painful?
•	How soon after the tests will I learn the results?

Treatment
 

•	What treatments are recommended for me?
•	What clinical trials are appropriate for my type of cancer?
•	Will I need to be in the hospital to receive my treatment? For how long?
•	How might my normal activities change during my treatment?

Side Effects
 

•	What side effects should I expect? How long will they last?
•	Whom should I call if I am concerned about a side effect?
•	What will be done if I have pain?

Follow-up
 

•	After treatment, how often do I need to be checked? What type of follow-up care should I have?
•	What type of nutritional support will I need? Where can I get it?
•	Will I eventually be able to resume my normal activities?

The Health Care Team
 

•	Who will be involved with my treatment and rehabilitation? What is the role of each member of the health care team in my care?
•	What has been your experience in caring for patients with esophageal cancer?

Resources
 

•	Are there support groups in the area with people I can talk to?
•	Are there organizations where I can get more information about cancer, specifically esophageal cancer?
•	Are there Web sites I can visit that have accurate information about cancer, especially esophageal cancer?

Source: National Cancer Institute
http://cancer.gov

v Stomach Cancer

Introduction

Each year, about 24,000 people in the United States learn that they have cancer of the stomach. This chapter will give you important information about the symptoms, diagnosis, and treatment of stomach cancer. It also has information to help you deal with this disease if it affects you or someone you know.

The Stomach

The stomach is part of the digestive system. It is located in the upper abdomen, under the ribs. The upper part of the stomach connects to the esophagus, and the lower part leads into the small intestine.

When food enters the stomach, muscles in the stomach wall create a rippling motion that mixes and mashes the food. At the same time, juices made by glands in the lining of the stomach help digest the food. After about 3 hours, the food becomes a liquid and moves into the small intestine, where digestion continues.

Stomach Cancer

Stomach cancer (also called gastric cancer) can develop in any part of the stomach and may spread throughout the stomach and to other organs. It may grow along the stomach wall into the esophagus or small intestine.

It also may extend through the stomach wall and spread to nearby lymph nodes and to organs such as the liver, pancreas, and colon. Stomach cancer also may spread to distant organs, such as the lungs, the lymph nodes above the collar bone, and the ovaries.

When cancer spreads to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if stomach cancer spreads to the liver, the cancer cells in the liver are stomach cancer cells. The disease is metastatic stomach cancer (it is not liver cancer). However, when stomach cancer spreads to an ovary, the tumor in the ovary is called a Krukenberg tumor. (This tumor, named for a doctor, is not a different disease; it is metastatic stomach cancer. The cancer cells in a Krukenberg tumor are stomach cancer cells, the same as the cancer cells in the primary tumor.)

Symptoms

Stomach cancer can be hard to find early. Often there are no symptoms in the early stages and, in many cases, the cancer has spread before it is found. When symptoms do occur, they are often so vague that the person ignores them. Stomach cancer can cause the following:
 

•	Indigestion or a burning sensation (heartburn);
•	Discomfort or pain in the abdomen;
•	Nausea and vomiting;
•	Diarrhea or constipation;
•	Bloating of the stomach after meals;
•	Loss of appetite;
•	Weakness and fatigue; and
•	Bleeding (vomiting blood or having blood in the stool).

Any of these symptoms may be caused by cancer or by other, less serious health problems, such as a stomach virus or an ulcer. Only a doctor can tell the cause. People who have any of these symptoms should see their doctor. They may be referred to a gastroenterologist, a doctor who specializes in diagnosing and treating digestive problems. These doctors are sometimes called gastrointestinal (or GI) specialists.

Causes of Stomach Cancer

The stomach cancer rate in the United States and the number of deaths from this disease have gone down dramatically over the past 60 years. Still, stomach cancer is a serious disease, and scientists all over the world are trying to learn more about what causes this disease and how to prevent it. At this time, doctors cannot explain why one person gets stomach cancer and another does not. They do know, however, that stomach cancer is not contagious; no one can “catch” cancer from another person.

Researchers have learned that some people are more likely than others to develop stomach cancer. The disease is found most often in people over age 55. It affects men twice as often as women, and is more common in black people than in white people. Also, stomach cancer is more common in some parts of the world–such as Japan, Korea, parts of Eastern Europe, and Latin America–than in the United States. People in these areas eat many foods that are preserved by drying, smoking, salting, or pickling. Scientists believe that eating foods preserved in these ways may play a role in the development of stomach cancer. On the other hand, fresh foods (especially fresh fruits and vegetables and properly frozen or refrigerated fresh foods) may protect against this disease.

Stomach ulcers do not appear to increase a person’s risk (chance) of getting stomach cancer. However, some studies suggest that a type of bacteria, Helicobacter pylori, which may cause stomach inflammation and ulcers, may be an important risk factor for this disease. Also, research shows that people who have had stomach surgery or have pernicious anemia, achlorhydria, or gastric atrophy (which generally result in lower than normal amounts of digestive juices) have an increased risk of stomach cancer.

Exposure to certain dusts and fumes in the workplace has been linked to a higher than average risk of stomach cancer. Also, some scientists believe smoking may increase stomach cancer risk.

People who think they might be at risk for stomach cancer should discuss this concern with their doctor. The doctor can suggest an appropriate schedule of checkups so that, if cancer appears, it can be detected as early as possible.

Diagnosis

To find the cause of symptoms, the doctor asks about the patient’s medical history, does a physical exam, and may order laboratory studies. The patient may also have one or all of the following exams:
 

•	Fecal occult blood test — a check for hidden (occult) blood in the stool. This test is done by placing a small amount of stool on a plastic slide or on special paper. It may be tested in the doctor’s office or sent to a laboratory. This test is done because stomach cancer sometimes causes bleeding that cannot be seen. However, noncancerous conditions also may cause bleeding, so having blood in the stool does not necessarily mean that a person has cancer.
•	Upper GI series — x-rays of the esophagus and stomach (the upper gastrointestinal, or GI, tract. The x-rays are taken after the patient drinks a barium solution, a thick, chalky liquid. (This test is sometimes called a barium swallow.) The barium outlines the stomach on the x-rays, helping the doctor find tumors or other abnormal areas. During the test, the doctor may pump air into the stomach to make small tumors easier to see.
•	Endoscopy — an exam of the esophagus and stomach using a thin, lighted tube called a gastroscope, which is passed through the mouth and esophagus to the stomach. The patient’s throat is sprayed with a local anesthetic to reduce discomfort and gagging. Patients also may receive medicine to relax them. Through the gastroscope, the doctor can look directly at the inside of the stomach. If an abnormal area is found, the doctor can remove some tissue through the gastroscope. Another doctor, a pathologist, examines the tissue under a microscope to check for cancer cells. This procedure — removing tissue and examining it under a microscope — is called a biopsy. A biopsy is the only sure way to know whether cancer cells are present.

A patient who needs a biopsy may want to ask the doctor some of these questions:
 

•	How long will the procedure take? Will I be awake? Will it hurt?
•	How soon will I know the results?
•	If I do have cancer, who will talk with me about treatment? When?

Staging

If the pathologist finds cancer cells in the tissue sample, the patient’s doctor needs to know the stage, or extent, of the disease. Staging exams and tests help the doctor find out whether the cancer has spread and, if so, what parts of the body are affected. Because stomach cancer can spread to the liver, the pancreas, and other organs near the stomach as well as to the lungs, the doctor may order a CT (or CAT) scan, an ultrasound exam, or other tests to check these areas.

Staging may not be complete until after surgery. The surgeon removes nearby lymph nodes and may take samples of tissue from other areas in the abdomen. All of these samples are examined by a pathologist to check for cancer cells. Decisions about treatment after surgery depend on these findings.

Treatment

The doctor develops a treatment plan to fit each patient’s needs. Treatment for stomach cancer depends on the size, location, and extent of the tumor; the stage of the disease; the patient’s general health; and other factors.

Many people who have cancer want to learn all they can about the disease and their treatment choices so they can take an active part in decisions about their medical care. The doctor is the best person to answer questions about their diagnosis and treatment plan.

When a person is diagnosed with cancer, shock and stress are natural reactions. These feelings may make it difficult for people to think of everything they want to ask the doctor. Often, it helps to make a list of questions. Also, to help remember what the doctor says, patients may take notes or ask whether they may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor — to take part in the discussion, to take notes, or just to listen. Patients should not feel the need to ask all their questions or remember all the answers at one time. They will have other chances to ask the doctor to explain things and to get more information.

When talking about treatment choices, the patient may want to ask about taking part in a research study. Such studies, called clinical trials, are designed to improve cancer treatment.

These are some questions a patient may want to ask the doctor before treatment begins:
 

•	What is the stage of the disease?
•	What are my treatment options? Which do you suggest for me? Why?
•	Would a clinical trial be appropriate for me?
•	What are the expected benefits of the treatment?
•	What are the risks and possible side effects of the treatment?
•	What can be done about side effects?
•	What can I do to take care of myself during therapy?
•	How long will my treatment last?

Patients and their loved ones are naturally concerned about the effectiveness of the treatment. Sometimes they use statistics to try to figure out whether the patient will be cured, or how long he or she will live. It is important to remember, however, that statistics are averages based on large numbers of patients. They cannot be used to predict what will happen to a particular person because no two cancer patients are alike; treatments and responses vary greatly. Patients may want to talk with the doctor about the chance of recovery (prognosis). When doctors talk about surviving cancer, they may use the term remission rather than cure. Even though many patients recover completely, doctors use this term because the disease can return. (The return of cancer is called a recurrence.)

Getting a Second Opinion

Treatment decisions are complex. Sometimes it is helpful for patients to have a second opinion about the diagnosis and the treatment plan. (Some insurance companies require a second opinion; others may pay for a second opinion if the patient requests it.) There are several ways to find another doctor to consult:
 

•	The patient’s doctor may be able to suggest a specialist. Specialists who treat this disease include gastroenterologists, surgeons, medical oncologists and radiation oncologists.
•	The Cancer Information Service, at 1-800-4-CANCER, can tell callers about treatment facilities, including cancer centers and other programs supported by the National Cancer Institute.
•	The American Board of Medical Specialties (ABMS) has a list of doctors who have met certain education and training requirements and have passed specialty examinations. The Official ABMS Directory of Board Certified Medical Specialists lists doctors’ names along with their specialty and their educational background. The directory is available in most public libraries. Also, ABMS offers this information on the Internet at http://www.abms.org. (Click on “Who’s Certified.”)

Methods of Treatment

Cancer of the stomach is difficult to cure unless it is found in an early stage (before it has begun to spread). Unfortunately, because early stomach cancer causes few symptoms, the disease is usually advanced when the diagnosis is made. However, advanced stomach cancer can be treated and the symptoms can be relieved. Treatment for stomach cancer may include surgery, chemotherapy, and/or radiation therapy. New treatment approaches such as biological therapy and improved ways of using current methods are being studied in clinical trials. A patient may have one form of treatment or a combination of treatments.

Surgery is the most common treatment for stomach cancer. The operation is called gastrectomy. The surgeon removes part (subtotal or partial gastrectomy) or all (total gastrectomy) of the stomach, as well as some of the tissue around the stomach. After a subtotal gastrectomy, the doctor connects the remaining part of the stomach to the esophagus or the small intestine. After a total gastrectomy, the doctor connects the esophagus directly to the small intestine. Because cancer can spread through the lymphatic system, lymph nodes near the tumor are often removed during surgery so that the pathologist can check them for cancer cells. If cancer cells are in the lymph nodes, the disease may have spread to other parts of the body.

These are some questions a patient may want to ask the doctor before surgery:
 

•	What kind of operation will I have?
•	What are the risks of this operation?
•	How will I feel afterwards? If I have pain, how will you help me?
•	Will I need a special diet? Who will teach me about my diet?

Chemotherapy is the use of drugs to kill cancer cells. This type of treatment is called systemic therapy because the drugs enter the bloodstream and travel through the body.

Clinical trials are in progress to find the best ways to use chemotherapy to treat stomach cancer. Scientists are exploring the benefits of giving chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy remaining cancer cells. Combination treatment with chemotherapy and radiation therapy is also under study. Doctors are testing a treatment in which anticancer drugs are put directly into the abdomen (intraperitoneal chemotherapy). Chemotherapy also is being studied as a treatment for cancer that has spread, and as a way to relieve symptoms of the disease.

Most anticancer drugs are given by injection; some are taken by mouth. The doctor may use one drug or a combination of drugs. Chemotherapy is given in cycles: a treatment period followed by a recovery period, then another treatment, and so on. Usually a person receives chemotherapy as an outpatient (at the hospital, at the doctor’s office, or at home). However, depending on which drugs are given and the patient’s general health, a short hospital stay may be needed.

These are some questions patients may want to ask about chemotherapy:
 

•	What is the goal of this treatment?
•	What drugs will I be taking?
•	Will the drugs cause side effects? What can I do about them?
•	How long will I need to take this treatment?
•	How will we know if the treatment is working?

Radiation therapy (also called radiotherapy) is the use of high-energy rays to damage cancer cells and stop them from growing. Like surgery, it is local therapy; the radiation can affect cancer cells only in the treated area. Radiation therapy is sometimes given after surgery to destroy cancer cells that may remain in the area. Researchers are conducting clinical trials to find out whether it is helpful to give radiation therapy during surgery (intraoperative radiation therapy). Radiation therapy may also be used to relieve pain or blockage.

The patient goes to the hospital or clinic each day for radiation therapy. Usually treatments are given 5 days a week for 5 to 6 weeks.

These are some questions a patient may want ask the doctor before receiving radiation therapy:
 

•	What is the goal of this treatment?
•	How will the radiation be given?
•	When will the treatment begin? When will it end?
•	Will I have side effects? What can I do about them?
•	How will we know if the radiation therapy is working?

Biological therapy (also called immunotherapy) is a form of treatment that helps the body’s immune system attack and destroy cancer cells; it may also help the body recover from some of the side effects of treatment. In clinical trials, doctors are studying biological therapy in combination with other treatments to try to prevent a recurrence of stomach cancer. In another use of biological therapy, patients who have low blood cell counts during or after chemotherapy may receive colony-stimulating factors to help restore the blood cell levels. Patients may need to stay in the hospital while receiving some types of biological therapy.

Clinical Trials

Many patients with stomach cancer are treated in clinical trials (treatment studies). Doctors conduct clinical trials to find out whether a new approach is both safe and effective and to answer scientific questions. Patients who take part in these studies are often the first to receive treatments that have shown promise in laboratory research. In clinical trials, some patients may receive the new treatment while others receive the standard approach. In this way, doctors can compare different therapies. Patients who take part in a trial make an important contribution to medical science and may have the first chance to benefit from improved treatment methods. Researchers also use clinical trials to look for ways to reduce the side effects of treatment and to improve the quality of patients’ lives.

Many clinical trials for people with stomach cancer are under way. Patients who are interested in taking part in a trial should talk with their doctor. The booklet Taking Part in Clinical Trials: What Cancer Patients Need To Know explains the possible benefits and risks of treatment studies.
One way to learn about clinical trials is through PDQ®, a computer database developed by the National Cancer Institute. PDQ contains information about cancer treatment and about clinical trials. The Cancer Information Service can provide PDQ information to doctors, patients, and the public.

Side Effects of Treatment

It is hard to limit the effects of therapy so that only cancer cells are removed or destroyed. Because healthy cells and tissues also may be damaged, treatment can cause unpleasant side effects.
The side effects of cancer treatment are different for each person, and they may even be different from one treatment to the next. Doctors try to plan treatment in ways that keep side effects to a minimum; they can help with any problems that occur. For this reason, it is very important to let the doctor know about any problems during or after treatment.

The National Cancer Institute booklets Radiation Therapy and You and Chemotherapy and You have helpful information about cancer treatment and coping with side effects.

Surgery

Gastrectomy is major surgery. For a period of time after the surgery, the person’s activities are limited to allow healing to take place. For the first few days after surgery, the patient is fed intravenously (through a vein). Within several days, most patients are ready for liquids, followed by soft, then solid, foods. Those who have had their entire stomach removed cannot absorb vitamin B12, which is necessary for healthy blood and nerves, so they need regular injections of this vitamin. Patients may have temporary or permanent difficulty digesting certain foods, and they may need to change their diet. Some gastrectomy patients will need to follow a special diet for a few weeks or months, while others will need to do so permanently. The doctor or a dietitian (a nutrition specialist) will explain any necessary dietary changes.

Some gastrectomy patients have cramps, nausea, diarrhea, and dizziness shortly after eating because food and liquid enter the small intestine too quickly. This group of symptoms is called the dumping syndrome. Foods containing high amounts of sugar often make the symptoms worse. The dumping syndrome can be treated by changing the patient’s diet. Doctors often advise patients to eat several small meals throughout the day, to avoid foods that contain sugar, and to eat foods high in protein. To reduce the amount of fluid that enters the small intestine, patients are usually encouraged not to drink at mealtimes. Medicine also can help control the dumping syndrome. The symptoms usually disappear in 3 to 12 months, but they may be permanent.

Following gastrectomy, bile in the small intestine may back up into the remaining part of the stomach or into the esophagus, causing the symptoms of an upset stomach. The patient’s doctor may prescribe medicine or suggest over-the-counter products to control such symptoms.

Chemotherapy

The side effects of chemotherapy depend mainly on the drugs the patient receives. As with any other type of treatment, side effects also vary from person to person. In general, anticancer drugs affect cells that divide rapidly. These include blood cells, which fight infection, help the blood to clot, or carry oxygen to all parts of the body. When blood cells are affected by anticancer drugs, patients are more likely to get infections, may bruise or bleed easily, and may have less energy. Cells in hair roots and cells that line the digestive tract also divide rapidly. As a result of chemotherapy, patients may have side effects such as loss of appetite, nausea, vomiting, hair loss, or mouth sores. For some patients, the doctor may prescribe medicine to help with side effects, especially with nausea and vomiting. These effects usually go away gradually during the recovery period between treatments or after the treatments stop.

Radiation Therapy  

Patients who receive radiation to the abdomen may have nausea, vomiting, and diarrhea. The doctor can prescribe medicine or suggest dietary changes to relieve these problems. The skin in the treated area may become red, dry, tender, and itchy. Patients should avoid wearing clothes that rub; loose-fitting cotton clothes are usually best. It is important for patients to take good care of their skin during treatment, but they should not use lotions or creams without the doctor’s advice. Patients are likely to become very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay as active as they can.

Biological Therapy

The side effects of biological therapy vary with the type of treatment. Some cause flu-like symptoms, such as chills, fever, weakness, nausea, vomiting, and diarrhea. Patients sometimes get a rash, and they may bruise or bleed easily. These problems may be severe, and patients may need to stay in the hospital during treatment.

Nutrition for Cancer Patients

It is sometimes difficult for patients who have been treated for stomach cancer to eat well. Cancer often causes loss of appetite, and people may not feel like eating when they are uncomfortable or tired. It is hard for patients to eat when they have nausea, vomiting, mouth sores, or the dumping syndrome. Patients who have had stomach surgery are likely to feel full after eating only a small amount of food. For some patients, the taste of food changes. Still, good nutrition is important. Eating well means getting enough calories and protein to help prevent weight loss, regain strength, and rebuild normal tissues.

Doctors, nurses, and dietitians can offer advice for healthy eating during and after cancer treatment. Patients and their families also may want to read the National Cancer Institute booklet Eating Hints for Cancer Patients, which contains many useful suggestions.

Support for Cancer Patients

Living with a serious disease is not easy. Cancer patients and those who care about them face many problems and challenges. Coping with these problems is often easier when people have helpful information and support services. Several useful booklets, including Taking Time, are available from the Cancer Information Service.

Cancer patients may worry about holding their job, caring for their family, or keeping up with their daily activities. Concerns about tests, treatments, hospital stays, and medical bills are common. Doctors, nurses, and other members of the health care team can answer questions about treatment, working, or other activities. Meeting with a social worker, counselor, or member of the clergy also can be helpful for patients who want to talk about their feelings or discuss their concerns about the future or about personal relationships.

Friends and relatives can be very supportive. Also, it helps many patients to discuss their concerns with others who have cancer. Cancer patients often get together in support groups, where they can share what they have learned about coping with cancer and the effects of treatment. It is important to keep in mind, however, that each patient is different. Treatments and ways of dealing with cancer that work for one person may not be right for another — even if they both have the same kind of cancer. It is always a good idea to discuss the advice of friends and family members with the doctor.

Often, a social worker at the hospital or clinic can suggest groups that can help with rehabilitation, emotional support, financial aid, transportation, or home care. For example, the American Cancer Society has many services for cancer patients and their families. Local offices of the American Cancer Society are listed in the white pages of the telephone directory. The Cancer Information Service also has information on local resources.

Vitamins, Anti-Bacterials May Prevent Stomach Cancer

Vitamin C, beta-carotene, and an antibacterial treatment may — singly or in combination — help prevent stomach (gastric) cancer, according to a long-term clinical trial involving more than 600 people at high risk of developing the disease. The results of the trial appear in the Dec. 6, 2000, issue of the Journal of the National Cancer Institute.

Gastric cancer is the second leading cause of cancer death in the world and five-year survival rates are low. An effective means of preventing the disease could have a dramatic impact on public health worldwide.

Pelayo Correa, M.D., and colleagues at Louisiana State University, New Orleans, together with researchers from Colombia, conducted the trial in an area of Colombia known for its high rate of gastric cancer. Participants were randomly assigned to receive either:
 

•	a standard treatment for H. pylori infection, a bacteria that has been associated with the development of gastric cancer;
•	one gram of ascorbic acid (vitamin C) twice a day;
•	30 milligrams of beta-carotene once a day;
•	various combinations of these treatments; or
•	a placebo.

To compare the treatments, the researchers looked at the status of precancerous abnormalities in the stomachs of each of the participants over the course of the six-year study. They analyzed biopsy specimens at the beginning of the study, after three years, and again after six years. The biopsies showed that precancerous abnormalities were more likely to shrink or disappear among people who received treatment than among those who took placebos.
The three different treatments all had about the same effect, and combining treatments did not appear to add any advantage.

For example, among people with a precancerous abnormality known as nonmetaplastic atrophy, those who received the anti-H. pylori treatment (an antibiotic plus other agents) were 4.8 times more likely than the placebo group to undergo a regression in their abnormalities. People with this condition receiving vitamin C were 5.0 times more likely to have abnormalities that regressed, and those receiving beta-carotene, 5.1 times more likely.

In an accompanying editorial, William Blot, Ph.D., of the International Epidemiology Institute in Rockville, Md., notes that the findings agree with those of other studies showing that people who eat many fruits and vegetables, which are rich sources of ascorbic acid and beta-carotene, have lower rates of gastric cancer. He cautions, however, that the findings must be confirmed by other studies.

A number of gastric cancer prevention trials are under way around the world. The largest, Correa said, is taking place in the Shandong province of China, where gastric cancer rates are very high. Sponsored by the National Cancer Institute, this trial is comparing the effects of vitamin and mineral supplements, a garlic extract, and anti-H. pylori treatment. Other trials are under way in Italy, England, Mexico, and elsewhere.

Other Booklets

National Cancer Institute printed materials, including the booklets listed below, are available from the Cancer Information Service free of charge by calling 1-800-4-CANCER.

Booklets About Cancer Treatment
 

•	Chemotherapy and You: A Guide to Self-Help During Treatment
•	Radiation Therapy and You: A Guide to Self-Help During Treatment
•	Taking Part in Clinical Trials: What Cancer Patients Need To Know
•	If You Have Cancer... What You Should Know About Clinical Trials
•	Eating Hints for Cancer Patients
•	Pain Control: A Guide for People with Cancer and Their Families
•	La participación en los estudios clínicos: Lo que los pacientes de cáncer deben saber (Taking Part in Clinical Trials: What Cancer Patients Need To Know)
•	Si tiene cáncer...lo que debería saber sobre estudios clínicos (If You Have Cancer... What You Should Know About Clinical Trials)

v Cancer of the Colon and Rectum

Facts and Figures

New Cases

An estimated 105,500 colon and 42,000 rectal cancer cases are expected to occur in 2003. Colorectal cancer is the third most common cancer in men and women. Incidence rates declined by 1.8% per year during 1985-1995, but stabilized during 1995-99. Research suggests that these declines may in part be due to increased screening and polyp removal, preventing progression of polyps to invasive cancers.

Deaths

An estimated 57,100 deaths are expected to occur in 2003, accounting for about 10% of cancer deaths. In contrast to incidence rates, which stabilized in the most recent time period, mortality rates continued to decline for both men and women over the past 15 years, at an average of 1.7% per year. This decrease reflects the decreasing incidence rates form the mid-1980s to the mid-1990s and improvements in survival.

Signs and symptoms: In its early stages, colorectal cancer usually causes no symptoms. Rectal bleeding, blood in the stool, a change in bowel habits, and cramping pain in the lower abdomen may signal advanced disease.

Risk Factors

The primary risk factor for colorectal cancer is age, with more than 90% of cases diagnosed in individuals over the age of 50. A personal or family history of colorectal cancer or polyps or of inflammatory bowel disease increases colorectal cancer risk. Other risk factors include smoking, alcohol consumption, obesity, physical inactivity, high-fat and/or low-fiber diet, as well as inadequate intake of fruits and vegetables. Recent studies have suggested that estrogen (with or without progestin) replacement therapy and nonsteroidal antiinflammatory drugs, such as aspirin, may reduce colorectal cancer risk.

Early Detection

Beginning at age 50, men and women who are at average risk for developing colorectal cancer should have one of the following: fecal occult blood test (FOBT) annually; or flexible sigmoidoscopy every 5 years; or the combination of annual FOBT and flexible sigmoidoscopy every 5 years (this combination is preferred over either method alone); colonoscopy (if normal, repeat every 10 years), or double-contrast barium enema (if normal, repeat every 5 years). A digital rectal examination should be done at the same time as sigmoidoscopy, colonoscopy, or double-contrast barium enema. These tests offer the best opportunity to detect colorectal cancer at an early stage when successful treatment is likely, and to prevent some cancers by detection and removal of polyps. People should begin colorectal cancer screening earlier and/or undergo screening more often if they have a personal history of colorectal cancer or adenomatous polyps, a strong family history of colorectal cancer or polyps, a personal history of chronic inflammatory bowel disease, or if they are a member of a family with hereditary colorectal cancer syndromes.

Treatment

Surgery is the most common form of treatment for colorectal cancer. For cancers that have not spread, it is frequently curative. Chemotherapy or chemotherapy plus radiation are given before or after surgery to most patients whose cancer has deeply perforated the bowel wall or has spread to the lymph nodes. A permanent colostomy (creation of an abdominal opening for elimination of body wastes) is very rarely needed for colon cancer and is infrequently required for rectal cancer. Among chemotherapy options, oxaliplatin in combination with 5-fluorouracil (5-FU) followed by leucovorin (LV) is a new treatment regimen for patients with metastatic carcinoma of the colon or rectum whose disease has recurred or progressed during or within six months of completion of first-line therapy with the combination of 5-FU/LV and irinotecan. Adjuvant chemotherapy for colon cancer is equally effective and no more toxic in otherwise healthy patients age 70 and older than in younger patients.

Survival

The 1-and 5-year relative survival rates for patients with colon and rectum cancer are 83% and 62%, respectively. When colorectal cancers are detected at an early, localized stage, the 5-year relative survival rate is 90%; however, only 37% of colorectal cancers are discovered at that stage. After the cancer has spread regionally to involve adjacent organs or lymph nodes, the rate drops to 65%. The 5-year survival rate for persons with distant metastases is 9%. Survival continues to decline beyond five years to 55% relative survival at 10 years after diagnosis. 



From “Cancer Facts and Figures 2003” published by the American Cancer Society®. 

The Colon and Rectum The colon and rectum are parts of the digestive system. They form a long, muscular tube called the large intestine (also called the large bowel). The colon is the first 4 to 5 feet of the large intestine, and the rectum is the last 4 to 5 inches. The part of the colon that joins to the rectum is the sigmoid colon. The part that joins to the small intestine is the cecum. Partly digested food enters the colon from the small intestine. The colon removes water and nutrients from the food and stores the rest as waste. The waste passes from the colon into the rectum and then out of the body through the anus.

Understanding Cancer

Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body.

Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place.

Sometimes this orderly process goes wrong. New cells form when the body does not need them, and cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.

Tumors can be benign or malignant:
 

•	Benign tumors are not cancer:

	Benign tumors are rarely life-threatening.
	Generally, benign tumors can be removed, and they usually do not grow back.
	Cells from benign tumors do not invade the tissues around them.
	Cells from benign tumors do not spread to other parts of the body.

•	Malignant tumors are cancer:

	Malignant tumors are generally more serious than benign tumors. They may be life-threatening.
	Malignant tumors usually can be removed, but sometimes they grow back.
	Cells from malignant tumors can invade and damage nearby tissues and organs.
	Cells from malignant tumors can spread to other parts of the body. The cells spread by breaking away from the original cancer (primary tumor) and entering the bloodstream or lymphatic system. They invade other organs, forming new tumors and damaging these organs. The spread of cancer is called metastasis.

Colorectal Cancer

Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancers affecting either of these organs may also be called colorectal cancer.

When colorectal cancer spreads outside the colon or rectum, cancer cells are often found in nearby lymph nodes. If cancer cells have reached these nodes, they may also have spread to other lymph nodes, the liver, or other organs.

When cancer spreads (metastasizes) from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if colorectal cancer spreads to the liver, the cancer cells in the liver are actually colorectal cancer cells. The disease is metastatic colorectal cancer, not liver cancer. It is treated as colorectal cancer, not liver cancer. Doctors sometimes call the new tumor “distant” or metastatic disease.

Colorectal Cancer: Who’s at Risk?

No one knows the exact causes of colorectal cancer. Doctors can seldom explain why one person develops the disease and another does not. However, it is clear that colorectal cancer is not contagious. No one can “catch” this disease from another person.
Research has shown that people with certain risk factors are more likely than others to develop colorectal cancer. A risk factor is anything that is linked to an increased chance of developing a disease.

Risk Factors

The most important common risk factor is age. Uncommon but very important risk factors include chronic ulcerative colitis or familial polyposis. Persons with ulcerative colitis have roughly a 1 percent per year risk to develop colorectal cancer after having had 8-10 years of extensive ulcerative colitis. Familial polyposis is a rare autosomal dominant disorder in which persons may have hundreds or thousands of adenomatous polyps. The genetic defect is located on chromosome 5. The risk of colorectal cancer is virtually 100 percent, and the recommended preventive treatment is prophylactic colectomy.

The two most common and important risk factors (besides age) for “ordinary” colorectal cancer are family history and a history of adenomatous polyps. Persons with one or more first-degree relatives with colorectal cancer may have a twofold increased cancer risk.

Adenomatous colon polyps deserve special comment because they are the presumed precursors of most colorectal cancer. If a large adenomatous colonic polyp is present and is left intact, it has roughly a 1 percent chance per year of becoming cancer. Although more than 30 percent of persons age 50 years and older have one or more adenomatous polyps, about 90 percent of these polyps are small (i.e., under 1 cm). After a polyp has been removed, the risk of cancer that “remains” in a person is not well known. In persons with high risk, aggressive follow-up surveillance using colonoscopy may be appropriate.
Studies have found the following risk factors for colorectal cancer:
 

•	Age: Colorectal cancer is more likely to occur as people get older. More than 90 percent of people with this disease are diagnosed after age 50. The average age at diagnosis is in the mid-60s.
•	Colorectal polyps: Polyps are growths on the inner wall of the colon or rectum. They are common in people over age 50. Most polyps are benign (noncancerous), but some polyps (adenomas) can become cancer. Finding and removing polyps may reduce the risk of colorectal cancer.
•	Family history of colorectal cancer: Close relatives (parents, brothers, sisters, or children) of a person with a history of colorectal cancer are somewhat more likely to develop this disease themselves, especially if the relative had the cancer at a young age. If many close relatives have a history of colorectal cancer, the risk is even greater.
•	Genetic alterations: Changes in certain genes increase the risk of colorectal cancer.

	Hereditary nonpolyposis colon cancer (HNPCC) is the most common type of inherited (genetic) colorectal cancer. It accounts for about 2 percent of all colorectal cancer cases. It is caused by changes in an HNPCC gene. About 3 out of 4 people with an altered HNPCC gene develop colon cancer, and the average age at diagnosis of colon cancer is 44.
	Familial adenomatous polyposis (FAP) is a rare, inherited condition in which hundreds of polyps form in the colon and rectum. It is caused by a change in a specific gene called APC. Unless familial adenomatous polyposis is treated, it usually leads to colorectal cancer by age 40. FAP accounts for less than 1 percent of all colorectal cancer cases.
	Family members of people who have HNPCC or FAP can have genetic testing to check for specific genetic changes. For those who have changes in their genes, health care providers may suggest ways to try to reduce the risk of colorectal cancer, or to improve the detection of this disease. For adults with FAP, the doctor may recommend an operation to remove all or part of the colon and rectum.

 

	Personal history of colorectal cancer: A person who has already had colorectal cancer may develop colorectal cancer a second time. Also, women with a history of cancer of the ovary, uterus (endometrium), or breast are at a somewhat higher risk of developing colorectal cancer.
	Ulcerative colitis or Crohn’s disease: A person who has had a condition that causes inflammation of the colon (such as ulcerative colitis or Crohn’s disease) for many years is at increased risk of developing colorectal cancer.
	Diet: Studies suggest that diets high in fat (especially animal fat) and low in calcium, folate, and fiber may increase the risk of colorectal cancer. Also, some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer. More research is needed to better understand how diet affects the risk of colorectal cancer.
	Cigarette smoking: A person who smokes cigarettes may be at increased risk of developing polyps and colorectal cancer.

People who think they may be at risk should discuss this concern with their doctor. The doctor may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups.

Screening

Screening for cancer before a person has symptoms can help the doctor find polyps or cancer early. Finding and removing polyps may prevent colorectal cancer. Also, treatment for colorectal cancer is more likely to be effective when the disease is found early.

To find polyps or early colorectal cancer:
 

•	People in their 50s and older should be screened.
•	People who are at higher-than-average risk of colorectal cancer should talk with their doctor about whether to have screening tests before age 50, what tests to have, the benefits and risks of each test, and how often to schedule appointments.

The following screening tests are used to detect polyps, cancer, or other abnormalities in the colon and rectum. The doctor can explain more about each test:
 

•	Fecal occult blood test (FOBT): Sometimes cancers or polyps bleed, and the FOBT can detect tiny amounts of blood in the stool. If this test detects blood, other tests are needed to find the source of the blood. Benign conditions (such as hemorrhoids) also can cause blood in the stool.
•	Sigmoidoscopy: The doctor checks inside the rectum and lower (sigmoid) colon with a lighted tube called a sigmoidoscope. If polyps are found, the doctor removes them. The procedure to remove polyps is called a polypectomy.
•	Colonoscopy: The doctor examines inside the rectum and entire colon using a long, lighted tube called a colonoscope. The doctor removes polyps that may be found.
•	Double-contrast barium enema (DCBE): A DCBE is a series of x-rays of the colon and rectum. The patient is given an enema with a barium solution, and air is pumped into the rectum. The barium and air outline the colon and rectum on the x-rays. Polyps may show up on the x-ray.
•	Digital rectal exam (DRE): A rectal exam is often part of a routine physical examination. The doctor or nurse inserts a lubricated, gloved finger into the rectum to feel for abnormal areas in the lower part of the rectum.

The NCI fact sheet, “Colorectal Cancer Screening: Questions and Answers,” has more information about these screening tests. It is available on the Internet at http://cancer.gov/publications and by calling 1-800-4-CANCER .

Are new tests under study for colorectal cancer screening?

New tests for colorectal cancer screening are under study. For example, virtual colonoscopy (also called computed tomographic colonography) is a procedure that uses special x-ray equipment to produce pictures of the colon. A computer then assembles these pictures into detailed images that can show polyps and other abnormalities. Because it is less invasive and does not require sedation, virtual colonoscopy may cause less discomfort and take less time than conventional colonoscopy. However, as with conventional colonoscopy and DCBE, thorough preparation of the colon is necessary before the test. Unlike conventional colonoscopy, it is not possible to remove polyps or perform a biopsy during virtual colonoscopy. An additional procedure, such as conventional colonoscopy, is needed if the virtual procedure finds a potential problem. Clinical trials (research studies with people) are under way to compare the advantages and disad.

Test	Advantages	Disadvantages
Fecal Occult Blood Test (FOBT)	• No preparation of the colon is necessary.  • Samples can be collected at home.  • Cost is low compared to other colorectal cancer screening tests.  • FOBT does not cause bleeding or tears in the lining of the colon.	• This test fails to detect most polyps and some cancers.  • False positive results are possible. (“False positive” means the test suggests an abnormality when none is present.)  • Dietary and other limitations, such as increasing fiber intake and avoiding meat, certain vegetables, vitamin C, iron, and aspirin, are often recommended for several days before the test.  • Additional procedures, such as colonoscopy, may be necessary if the test indicates an abnormality.
Sigmoidoscopy	• The test is usually quick, with few complications.  • Discomfort is minimal.  • In some cases, the doctor may be able to perform a biopsy (the removal of tissue for examination under a microscope by a pathologist) and remove polyps during the test, if necessary.  • Less extensive preparation of the colon is necessary with this test than for a colonoscopy.	• This test allows the doctor to view only the rectum and the lower part of the colon. Any polyps in the upper part of the colon will be missed.  • There is a very small risk of bleeding or tears in the lining of the colon.  • Additional procedures, such as colonoscopy, may be necessary if the test indicates an abnormality.
Colonoscopy	• This test allows the doctor to view the rectum and the entire colon.  • The doctor can perform a biopsy and remove polyps during the test, if necessary.	• The test may not detect all small polyps and cancers, but it is the most sensitive test currently available.  • Thorough preparation of the colon is necessary before the test.
Double Contrast Barium  Enema(DCBE)	• This test usually allows the doctor to view the rectum and the entire colon.  • Complications are rare.  • No sedation is necessary. • Often part of a routine physical examination.  • No preparation of the colon is necessary.	• Sedation is usually needed.  • Although uncommon, complications such as bleeding and/or tears in the lining of the colon can occur. • The test may not detect some small polyps and cancers.  • Thorough preparation of the colon is necessary before the test.  • False positive results are possible.  • The doctor cannot perform a biopsy or remove polyps during the test.  • Additional procedures are necessary if the test indicates an abnormality.
Digital Rectal Exam (DRE)	• The test is usually quick and painless.	• The test can detect abnormalities only in the lower part of the rectum.  • Additional procedures are necessary if the test indicates

vantages of virtual colonoscopy with those of other colorectal cancer screening tests. Genetic testing of stool samples is also under study as a possible way to screen for colorectal cancer. The lining of the colon is constantly shedding cells into the stool. Testing stool samples for genetic alterations that occur in colorectal cancer cells may help doctors find evidence of cancer or precancerous polyps. Research conducted thus far has shown that this test can detect colorectal cancer in people already diagnosed with this disease by other means. However, more studies are needed to determine whether the test can detect colorectal cancer or precancerous polyps in people who do not have symptoms. Additional information about clinical trials to test new methods for colorectal cancer screening is available from the NCI’s Web site at http://www.cancer.gov/clinicaltrials/ on the Internet, or by calling the CIS at 1-800-4-CANCER (1-422-6237)

People may want to ask the doctor the following questions about screening:  • Which tests do you recommend for me? Why? • How much do the tests cost? Will my health insurance plan help pay for screening tests? • Are the tests painful? • How soon after the tests will I learn the results?

Symptoms

Common symptoms of colorectal cancer include:
 

•	A change in bowel habits
•	Diarrhea, constipation, or feeling that the bowel does not empty completely
•	Blood (either bright red or very dark) in the stool
•	Stools that are narrower than usual
•	General abdominal discomfort (frequent gas pains, bloating, fullness, and/or cramps)
•	Weight loss with no known reason
•	Constant tiredness
•	Nausea and vomiting

Most often, these symptoms are not due to cancer. Other health problems can cause the same symptoms. Anyone with these symptoms should see a doctor so that any problem can be diagnosed and treated as early as possible.
Usually, early cancer does not cause pain. It is important not to wait to feel pain before seeing a doctor.

Diagnosis

If a person has any signs or symptoms of colorectal cancer, the doctor must determine whether they are due to cancer or some other cause. The doctor asks about personal and family medical history and may do a physical exam. The person may have one or more of the tests described in the “Screening” section.
If the physical exam and test results do not suggest cancer, the doctor may decide that no further tests are needed and no treatment is necessary. However, the doctor may recommend a schedule for checkups.

If tests show an abnormal area (such as a polyp), a biopsy to check for cancer cells may be necessary. Often, the abnormal tissue can be removed during colonoscopy or sigmoidoscopy. A pathologist checks the tissue for cancer cells using a microscope.

People may want to ask the doctor these questions before having a biopsy:   • How will the biopsy be done? • Will I have to go to the hospital for the biopsy? • How long will it take? Will I be awake? Will it hurt? • Are there any risks? What are the chances of infection or bleeding after the biopsy? • How long will it take me to recover? When can I resume a normal diet? • How soon will I know the results? • If I do have cancer, who will talk to me about the next steps? When?

Staging

If the biopsy shows that cancer is present, the doctor needs to know the extent (stage) of the disease to plan the best treatment. The stage is based on whether the tumor has invaded nearby tissues, whether the cancer has spread and, if so, to what parts of the body. Staging may involve some of the following tests and procedures:
 

•	Blood tests: The doctor checks for carcinoembryonic antigen (CEA) and other substances in the blood. Some people who have colorectal cancer or other conditions have a high CEA level.
•	Colonoscopy: If colonoscopy was not performed for diagnosis, the doctor examines the entire length of the colon and rectum with a colonoscope to check for other abnormal areas.
•	Endorectal ultrasound: An ultrasound probe is inserted into the rectum. The probe sends out sound waves that people cannot hear. The waves bounce off the rectum and nearby tissues, and a computer uses the echoes to create a picture. The picture shows how deep a rectal tumor has grown or whether the cancer has spread to lymph nodes or other nearby tissues.
•	Chest x-ray: X-rays of the chest can show whether cancer has spread to the lungs.
•	CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of areas inside the body. The patient may receive an injection of dye. Tumors in the liver, lungs, or elsewhere in the body show up on the CT scan.

The doctor also may use other tests (such as MRI) to see whether the cancer has spread. Sometimes staging is not complete until the patient has surgery to remove the tumor.

Doctors describe colorectal cancer by the following stages:
 

•	Stage 0: The cancer is found only in the innermost lining of the colon or rectum. Carcinoma in situ is another name for Stage 0 colorectal cancer.
•	Stage I: The cancer has grown into the inner wall of the colon or rectum. The tumor has not reached the outer wall of the colon or extended outside the colon. Dukes’ A is another name for Stage I colorectal cancer.
•	Stage II: The tumor extends more deeply into or through the wall of the colon or rectum. It may have invaded nearby tissue, but cancer cells have not spread to the lymph nodes. Dukes’ B is another name for Stage II colorectal cancer.
•	Stage III: The cancer has spread to nearby lymph nodes, but not to other parts of the body. Dukes’ C is another name for Stage III colorectal cancer.
•	Stage IV: The cancer has spread to other parts of the body, such as the liver or lungs. Dukes’ D is another name for Stage IV colorectal cancer.
•	Recurrent cancer: This is cancer that has been treated and has returned after a period of time when the cancer could not be detected. The disease may return in the colon or rectum, or in another part of the body.

Treatment

Many people with colorectal cancer want to take an active part in making decisions about their medical care. They want to learn all they can about their disease and their treatment choices. However, shock and stress after the diagnosis can make it hard to think of everything they want to ask the doctor. It often helps to make a list of questions before an appointment. To help remember what the doctor says, people may take notes or ask whether they may use a tape recorder. When they talk to the doctor, some people also want to have a family member or friend with them to take part in the discussion, to take notes, or just to listen.

The doctor may refer a person with colorectal cancer to a specialist, or the patient may ask for a referral. Specialists who treat colorectal cancer include gastroenterologists (doctors who specialize in diseases of the digestive system), surgeons, medical oncologists, and radiation oncologists.

Getting a Second Opinion

Before starting treatment, people with colorectal cancer might want a second opinion about their diagnosis and treatment options. Some insurance companies require a second opinion; others may cover a second opinion if the patient or doctor requests it. It may take some time and effort to gather medical records and arrange to see another doctor. In general, taking several weeks to get a second opinion does not make treatment less effective. In some cases, however, people with colorectal cancer need immediate care.

There are a number of ways to find a doctor for a second opinion:
 

•	The doctor may refer the patient to one or more specialists. At cancer centers, several specialists often work together as a team.
•	The Cancer Information Service, at 1-800-4-CANCER, can tell callers about nearby treatment centers.
•	A local or state medical society, a nearby hospital, or a medical school can usually provide the names of specialists.
•	The American Board of Medical Specialties (ABMS) has a list of doctors who have met certain education and training requirements and have passed specialty examinations. The Official ABMS Directory of Board Certified Medical Specialists lists doctors’ names along with their specialty and their educational background. The directory is available in most public libraries. Also, ABMS offers this information on the Internet at http://www.abms.org. (Click on “Who’s Certified.”)
•	The NCI provides a helpful fact sheet called “How To Find a Doctor or Treatment Facility If You Have Cancer.” It is available on the Internet at http://cancer.gov/publications and may be ordered from the Cancer Information Service at 1-800-4-CANCER.

Preparing for Treatment

The doctor develops a treatment plan to fit each person’s needs. Treatment for colorectal cancer depends mainly on the location of the tumor in the colon or rectum and the stage of the disease. The doctor can describe the treatment choices and the expected results.

People may want to ask the doctor these questions before treatment begins:   • What is the stage of the disease? • What are my treatment choices? Which do you recommend for me? Will I have more than one kind of treatment? • What are the expected benefits of each kind of treatment? • What are the risks and possible side effects of each treatment? How can the side effects be managed? • How will treatment affect my normal activities? Am I likely to have urinary problems? What about bowel problems, such as diarrhea or rectal bleeding? Is treatment likely to affect my sex life? • What will the treatment cost? Is this treatment covered by my insurance plan? • Would a clinical trial (research study) be appropriate for me?

People do not need to ask all of their questions at once. They will have other chances to ask the doctor to explain things that are not clear and to ask for more information.

Methods of Treatment

Treatment for colorectal cancer may involve surgery, radiation therapy, or chemotherapy. Some people have a combination of treatments.
Colon cancer sometimes is treated differently from rectal cancer. Treatments for colon and rectal cancer are described separately.

At any stage of colorectal cancer, treatments are available to control pain and other symptoms, to relieve the side effects of therapy, and to ease emotional and practical problems. This kind of treatment is called supportive care, symptom management, or palliative care. Information about supportive care and coping with cancer is available on NCI’s Web site at http://cancer.gov/cancerinfo/coping/ and from NCI’s Cancer Information Service at 1-800-4-CANCER.
People with colorectal cancer may want to talk to the doctor about taking part in a clinical trial, a research study of new treatment methods. The section on “The Promise of Cancer Research” has more information about clinical trials.

Surgery

Surgery is the most common treatment for colorectal cancer. It is a type of local therapy. It treats the cancer in the colon or rectum and the area close to the tumor.
A small malignant polyp may be removed from the colon or upper rectum with a colonoscope. Some small tumors in the lower rectum can be removed through the anus without a colonoscope.

For a larger cancer, the surgeon makes an incision into the abdomen to remove the tumor and part of the healthy colon or rectum. Some nearby lymph nodes also may be removed. The surgeon checks the rest of the intestine and the liver to see if the cancer has spread.

When a section of the colon or rectum is removed, the surgeon can usually reconnect the healthy parts. However, sometimes reconnection is not possible. In this case, the surgeon creates a new path for waste to leave the body. The surgeon makes an opening (a stoma) in the wall of the abdomen, connects the upper end of the intestine to the stoma, and closes the other end. The operation to create the stoma is called a colostomy. A flat bag fits over the stoma to collect waste, and a special adhesive holds it in place.

For most people who have a colostomy, it is temporary. It is needed only until the colon or rectum heals from surgery. After healing takes place, the surgeon reconnects the parts of the intestine and closes the stoma. Some people, especially those with a tumor in the lower rectum, need a permanent colostomy.

People may want to ask the doctor these questions before having surgery:   • What kind of operation do you recommend for me? • Do I need any lymph nodes removed? Will other tissues be removed? Why? • What are the risks of surgery? Will I have any lasting side effects? • Will I need a colostomy? If so, will it be permanent? • How will I feel after the operation? • If I have pain, how will it be controlled? • How long will I be in the hospital? • When can I get back to my normal activities?

Chemotherapy

Chemotherapy uses anticancer drugs to kill cancer cells. It is called systemic therapy because it enters the bloodstream and can affect cancer cells throughout the body.

The patient may have chemotherapy alone or combined with surgery, radiation therapy, or both. Chemotherapy given before surgery is called neoadjuvant therapy. Chemotherapy before surgery may shrink a large tumor.
Chemotherapy after surgery is called adjuvant therapy. Adjuvant therapy is used to destroy any remaining cancer cells and prevent the cancer from coming back in the colon or rectum, or elsewhere.
Chemotherapy is also used to treat people with advanced disease.

Anticancer drugs are usually given through a vein, but some also may be given by mouth. The patient may be treated in an outpatient part of the hospital, at the doctor’s office, or at home. Rarely, a hospital stay may be needed.

People may want to ask the doctor these questions before having chemotherapy:   • Why do I need this treatment? • Which drug or drugs will I have? • How do the drugs work? • What are the expected benefits of the treatment? • What are the risks and possible side effects of treatment? What can I do about them? • When will treatment start? When will it end? • How will treatment affect my normal activities?

Radiation Therapy

Radiation therapy (also called radiotherapy) is local therapy. It uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area.
Doctors use two types of radiation therapy to treat cancer. Sometimes people receive both types:
 

•	External radiation: The radiation comes from a machine. Most patients go to the hospital or clinic for their treatment, generally 5 days a week for several weeks. In some cases, external radiation is given during surgery.
•	Internal radiation (implant radiation): The radiation comes from radioactive material placed in thin tubes put directly into or near the tumor. The patient stays in the hospital, and the implants generally remain in place for several days. Usually they are removed before the patient goes home.

People may want to ask the doctor these questions before having radiation therapy:   • Why do I need this treatment? • What are the risks and side effects of this treatment? • Are there any long-term effects? • When will the treatments begin? When will they end? • How will I feel during therapy? • What can I do to take care of myself during therapy? • Can I continue my normal activities?

Treatment for Colon Cancer

Most patients with colon cancer are treated with surgery. Some have both surgery and chemotherapy. A colostomy is seldom needed for people with colon cancer.
Although radiation therapy is not commonly used to treat colon cancer, sometimes it is used to relieve pain and other symptoms.

Treatment for Rectal Cancer

For all stages of rectal cancer, surgery is the most common treatment. Some patients receive surgery, radiation therapy, and chemotherapy. About 1 out of 8 people with rectal cancer needs a permanent colostomy.

Radiation therapy may be used before and after surgery. Some people have radiation therapy before surgery to shrink the tumor, and some have it after surgery to kill cancer cells that may remain in the area. At some hospitals, patients may have radiation therapy during surgery. This is called IORT. People also may have radiation therapy to relieve pain and other problems caused by the cancer.

Side Effects of Cancer Treatment

Because treatment often damages healthy cells and tissues, unwanted side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person, and they may change from one treatment session to the next. Before treatment starts, the health care team will explain possible side effects and suggest ways to help the patient manage them.

The NCI provides helpful booklets about cancer treatments and coping with side effects. Booklets such as Radiation Therapy and You, Chemotherapy and You, and Eating Hints for Cancer Patients may be viewed, downloaded, and ordered from http://cancer.gov/publications. These materials also may be ordered by calling the Cancer Information Service at 1-800-4-CANCER.

Surgery

It takes time to heal after surgery, and the time needed to recover is different for each person. Patients are often uncomfortable during the first few days. However, medicine can usually control their pain. Before surgery, patients should discuss the plan for pain relief with the doctor or nurse. After surgery, the doctor can adjust the plan if more pain relief is needed.

It is common to feel tired or weak for a while. Also, surgery sometimes causes constipation or diarrhea. The health care team monitors the patient for signs of bleeding, infection, or other problems requiring immediate treatment.

People who have a colostomy may have irritation of the skin around the stoma. The doctor, nurse, or enterostomal therapist can teach patients how to clean the area and prevent irritation and infection. The section called “Rehabilitation” has more information about how patients learn to care for the stoma.

Chemotherapy

The side effects of chemotherapy depend mainly on the specific drugs and the dose. In general, anticancer drugs affect cells that divide rapidly, especially:|
 

•	Blood cells: These cells fight infection, help the blood to clot, and carry oxygen to all parts of the body. When drugs affect blood cells, patients are more likely to get infections, bruise or bleed easily, or feel very weak and tired.
•	Cells in hair roots: Chemotherapy can cause hair loss. The hair grows back, but sometimes the new hair is somewhat different in color and texture.
•	Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores. Many of these side effects can be controlled with drugs.

Radiation Therapy

The side effects of radiation therapy depend mainly on the amount of radiation given and the part of the body that is treated. Radiation therapy to the abdomen and pelvis may cause nausea, vomiting, diarrhea, bloody stools, rectal leakage, or urinary discomfort. In addition, the skin in the treated area may become red, dry, and tender.

Patients are likely to become very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay as active as they can.

Although the side effects of radiation therapy can be distressing, the doctor can usually treat or control them.

Nutrition

It is important to eat well during cancer treatment. Eating well means getting enough calories to maintain a good weight and enough protein to keep up strength. Good nutrition often helps people with cancer feel better and have more energy.

But eating well can be difficult. Patients may not feel like eating if they are uncomfortable or tired. Also, the side effects of treatment, such as poor appetite, nausea, vomiting, or mouth sores, can be a problem. Some people find that foods do not taste as good during cancer therapy.

The doctor, dietitian, or other health care provider can suggest ways to maintain a healthy diet. Patients and their families may want to read the National Cancer Institute booklet Eating Hints for Cancer Patients, which contains many useful ideas and recipes. The “National Cancer Institute Booklets” section tells how to get this publication.


Rehabilitation

Rehabilitation is an important part of cancer care. The health care team makes every effort to help the patient return to normal activities as soon as possible.

A person with a stoma needs to learn to care for it. Doctors, nurses, and enterostomal therapists can help. Often, enterostomal therapists visit the person before surgery to discuss what to expect. They teach the person how to care for the stoma after surgery. They talk about lifestyle issues, including emotional, physical, and sexual concerns. Often they can provide information about resources and support groups.

Follow-up Care

Follow-up care after treatment for colorectal cancer is important. Even when the cancer seems to have been completely removed or destroyed, the disease sometimes returns because undetected cancer cells remained somewhere in the body after treatment. The doctor monitors the person’s recovery and checks for recurrence of the cancer. Checkups help ensure that any changes in health are noted. Checkups may include a physical exam (including a digital rectal exam), lab tests (including fecal occult blood test and CEA test), colonoscopy, x-rays, CT scans, or other tests. Between scheduled visits with the doctor, patients should contact the doctor as soon as any health problems appear.

The NCI has prepared a booklet for people who have completed their treatment to help answer questions about follow-up care and other concerns. Facing Forward Series: Life After Cancer Treatment provides tips for making the best use of medical visits. It describes how to talk to the doctor about creating a plan of action for recovery and future health.

Support for People with Colorectal Cancer

Living with a serious disease such as colorectal cancer is not easy. People may worry about caring for their families, keeping their jobs, or continuing daily activities. Concerns about treatments and managing side effects, hospital stays, and medical bills are also common. Doctors, nurses, and other members of the health care team can answer questions about treatment, working, or other activities. Meeting with a social worker, counselor, or member of the clergy can be helpful to those who want to talk about their feelings or discuss their concerns. Often, a social worker can suggest resources for financial aid, transportation, home care, or emotional support.

Support groups also can help. In these groups, patients or their family members meet with other patients or their families to share what they have learned about coping with the disease and the effects of treatment. Groups may offer support in person, over the telephone, or on the Internet. Patients may want to talk with a member of their health care team about finding a support group.

The Cancer Information Service can provide information to help patients and their families locate programs, services, and publications.

The Promise of Cancer Research

Doctors all over the country are conducting many types of clinical trials (research studies in which people volunteer to take part). Doctors are studying new ways to prevent, detect, diagnose, and treat colorectal cancer.

Clinical trials are designed to answer important questions and to find out whether the new approach is safe and effective. Research already has led to advances in these areas, and researchers continue to search for more effective approaches.

People who join clinical trials may be among the first to benefit if a new approach is shown to be effective. And if participants do not benefit directly, they still make an important contribution to medicine by helping doctors learn more about the disease and how to control it. Although clinical trials may pose some risks, researchers do all they can to protect their patients.

People who are interested in being part of a clinical trial should talk with their doctor. They may want to read the NCI booklets Taking Part in Clinical Trials: What Cancer Patients Need To Know or Taking Part in Clinical Trials: Cancer Prevention Studies. The NCI also offers an easy-to-read brochure called If You Have Cancer...What You Should Know About Clinical Trials. These NCI publications describe how clinical trials are carried out and explain their possible benefits and risks.

NCI’s Web site includes a section on clinical trials at http://cancer.gov/clinicaltrials with general information about clinical trials as well as detailed information about specific ongoing studies of colorectal cancer. The Cancer Information Service at 1-800-4-CANCER or at Live Help at http://cancer.gov can answer questions and provide information about clinical trials.


Source: National Cancer Institute

v Pancreatic Cancer

In the United States approximately 27,000 people per year are diagnosed as having cancer of the pancreas. About 25,000 die of the disease. One-year survival is only 18 percent, and 5-year survival is 2 percent. There is some variation in survival, however. There are groups of patients whose survival is considerably better and some whose survival is considerably worse.

Incidence and mortality rates increase greatly with age, but age-adjusted rates for pancreatic cancer in the United States have not changed appreciably since 1973. The trend for white men has been slightly downward, whereas for blacks and white women it has been slightly upward. Hospital discharges numbered about 60,000 per year in the mid 1980’s.

Etiologically, only cigarette smoking is a strong, consistent indicator of elevated risk of developing pancreatic cancer. High fat diets may be positively associated, and raw fruit and vegetable diets may be negatively associated. Preexisting diabetes also appears to increase risk. Many suspected etiologic agents have been investigated, but their associations with cancer of the pancreas are, on the whole, poorly established.

Early diagnosis of pancreatic cancer has been extremely difficult. Cases that are still localized enough to be surgically resectable are rarely detected. A small improvement in survival has occurred over the past 15 years, indicating, perhaps, some improvement in early case finding. The whole problem cries out for intensive and extensive study.

Diagnosis

Pancreatic carcinoma is rarely diagnosed at an early (that is, curable) stage. Inaccessibility of the pancreas and vague initial symptoms make diagnosis difficult. Nevertheless, given that a patient has symptoms of pancreatic disease, such as abdominal pain, unexplained weight loss, sudden appearance of jaundice, and given that no other abdominal disorder is apparent, the following algorithm has been suggested by many practitioners:

We now recommend that ultrasonography be done first. If the results are negative or indeterminate, computerized tomography (CT) should be performed next, followed by endoscopic retrograde pancreatography (ERP). The pancreatic function test only rarely is needed. This sequence of tests should identify pancreatic disease and make the differentiation between pancreatitis and cancer in 90 percent of the patients. We choose ultrasonography first and reserve CT scanning and ERP as second and third tests because ultrasonography, in contrast to the other tests, does not require ionizing radiation, is more widely available, is not invasive, and has the same sensitivity and specificity as CT scanning.

SELECTED REFERENCES
 

1.	Anderson WF, Guyton KZ, Hiatt RA, et al. Colorectal cancer screening for persons at average risk. Journal of the National Cancer Institute 2002; 94(15):1126-1133.
2.	Dong SM, Traverso G, Johnson C, et al. Detecting colorectal cancer in stool with the use of multiple genetic targets. Journal of the National Cancer Institute 2001; 93(11):858-865.
3.	Gatto NM, Frucht H, Sundararajan V, et al. Risk of perforation after colonoscopy and sigmoidoscopy: A population-based study. Journal of the National Cancer Institute 2003; 95(3):230-236.
4.	Levin B. Overview of colorectal cancer screening in the United States. Journal of Psychological Oncology 2001; 19(3/4):9-19.
5.	Lieberman DA, Harford WV, Ahnen DJ, et al. One-time screening for colorectal cancer with combined fecal occult-blood testing and examination of the distal colon. New England Journal of Medicine 2001; 345(8):555-560.
6.	Lieberman DA, Weiss DG, Bond JH, et al. Use of colonoscopy to screen asymptomatic adults for colorectal cancer. New England Journal of Medicine 2000; 343(3):162-168.
7.	Mandel JS, Church TR, Bond JH, et al. The effect of fecal occult-blood screening on the incidence of colorectal cancer. New England Journal of Medicine 2000; 343(22):1603-1607.
8.	Pickhardt PJ, Choi JR, Hwang I, et al. Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. New England Journal of Medicine 2003; 349(23):2191–2200.
9.	Ransohoff DF, and Sandler RS. Screening for colorectal cancer. New England Journal of Medicine 2002; 346(1):40-44.
10.	Walsh JME, and Terdiman JP. Colorectal cancer screening: Scientific review. Journal of the American Medical Association 2003; 289(10):1288-1296.
11.	Winawer SJ, Stewart ET, Zauber AG, et al. A comparison of colonoscopy and double-contrast barium enema for surveillance after polypectomy. New England Journal of Medicine 2000; 342(24):1766-1772.
12.	Yee J, Akerkar GA, Hung RK, et al. Colorectal neoplasia: Performance characteristics of CT colonography for detection in 300 patients. Radiology 2001; 219(3):685-692.

Source: National Cancer Institute
http://cancer/gov
http://cancer.gov/cancertopics/types/stomach