- About Screening
- Screening Tests
- Screening Risks
Screening is looking for cancer before a person has any symptoms. This can help find cancer at an early stage. When abnormal tissue or cancer is found early, it may be easier to treat. By the time symptoms appear, cancer may have begun to spread.
Scientists are trying to better understand which people are more likely to get certain types of cancer. They also study the things we do and the things around us to see if they cause cancer. This information helps doctors recommend who should be screened for cancer, which screening tests should be used, and how often the tests should be done.
It is important to remember that your doctor does not necessarily think you have cancer if he or she suggests a screening test. Screening tests are given when you have no cancer symptoms.
If a screening test result is abnormal, you may need to have more tests done to find out if you have cancer. These are called diagnostic tests.
See the following PDQ summaries for information about prevention, diagnosis, and treatment of stomach cancer.
- Stomach (Gastric) Cancer Prevention
- Gastric Cancer Treatment
stomach is a J-shaped organ in the upper abdomen. It is part of the
digestive system, which processes nutrients (vitamins, minerals,
carbohydrates, fats, proteins, and water) in foods that are eaten and
helps pass waste material out of the body. Food moves from the throat
to the stomach through a hollow, muscular tube called the esophagus.
After leaving the stomach, partly-digested food passes into the small
intestine and then into the large intestine.
The stomach and esophagus are part of the upper digestive system.
The wall of the stomach is made up of 3 layers of tissue: the mucosal (innermost) layer, the muscularis (middle) layer, and the serosal (outermost) layer. Stomach cancer begins in the cells lining the mucosal layer and spreads through the outer layers as it grows.Stomach cancer is less common in the United States than in the developing world.
Stomach cancer is the fourteenth most frequent cause of cancer death in the United States. This type of cancer is much more common in many parts of Europe, Asia, and Central and South America, and is a major cause of death in the developing world.
Stomach cancer rates in the United States have greatly decreased since 1930. The reasons for this are not known, but may have to do with better food storage or changes in the diet, such as lower salt intake.Older age and certain chronic conditions increase the risk of developing stomach cancer.
Anything that increases the chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for stomach cancer include the following:
- Having any of the following medical conditions:
- Helicobacter pylori (H. pylori) infection of the stomach.
- Chronic gastritis (inflammation of the stomach).
- Pernicious anemia.
- Intestinal metaplasia (a condition in which the normal stomach lining is replaced with the cells that line the intestines).
- Familial adenomatous polyposis (FAP) or gastric polyps.
- Being older or male.
- Eating a diet high in salted, smoked foods and low in fruits and vegetables.
- Eating foods that have not been prepared or stored properly.
- Smoking cigarettes.
- Having a mother, father, sister, or brother who has had stomach cancer.
Some screening tests are used because they have been shown to be helpful both in finding cancers early and in decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.
Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person's chance of dying from the disease. For some types of cancer, the chance of recovery is better if the disease is found and treated at an early stage.
Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site.There is no standard or routine screening test for stomach cancer.
Upper endoscopy has been studied as a screening test to find stomach
cancer at an early stage. Upper endoscopy is a procedure to look inside
the esophagus, stomach, and duodenum (first part of the small
intestine) to check for abnormal areas. An endoscope, a thin, tube-like
instrument with a light and a lens for viewing, is passed through the
mouth and down the throat into the esophagus. It may also have a tool
to remove tissue to be checked under a microscope for signs of disease.
Upper endoscopy. A thin, lighted tube is inserted through the mouth to look for abnormal areas in the esophagus, stomach, and first part of the small intestine.
Some studies show that screening for stomach cancer in the United States would not result in a lower death rate. More research is needed to decide if it would be worthwhile to screen people in the United States who have a high risk for the disease. High risk groups that may benefit from stomach cancer screening include:
- Older people with gastritis or pernicious anemia.
- Patients with any of the following:
- Partial gastrectomy.
- Polyps in the stomach.
- Familial adenomatous polyposis (FAP).
- Hereditary nonpolyposis colon cancer (HNPCC).
- Immigrants from countries where stomach cancer is more common.
Decisions about screening tests can be difficult. Not all screening tests are helpful and most have risks. Before having any screening test, you may want to discuss the test with your doctor. It is important to know the risks of the test and whether it has been proven to reduce the risk of dying from cancer.The risks of stomach cancer screening include the following:Finding stomach cancer may not improve health or help you live longer.
Screening may not improve your health or help you live longer if you have advanced stomach cancer or if it has already spread to other places in your body.
Some cancers never cause symptoms or become life-threatening, but if found by a screening test, the cancer may be treated. It is not known if treatment of these cancers would help you live longer than if no treatment were given, and treatments for cancer may have serious side effects.False-negative test results can occur.
Screening test results may appear to be normal even though stomach cancer is present. A person who receives a false-negative result (one that shows there is no cancer when there really is) may delay seeking medical care even if there are symptoms.False-positive test results can occur.
Screening test results may appear to be abnormal even though no cancer is present. A false-positive test result (one that shows there is cancer when there really isn't) can cause anxiety and is usually followed by more tests and procedures which also have risks.Side effects may be caused by the screening test itself.
Upper endoscopy may cause the following rare, but serious, side effects:
- A small hole (puncture) in the esophagus or stomach.
- Heart problems.
- Breathing problems.
- Lung infection from inhaling food, fluid, or stomach acid into the lung.
- Severe bleeding that needs to be treated at a hospital.