Even though we do not know the exact cause of stomach cancer, it is still possible to prevent many stomach cancers.

The dramatic decline of stomach cancer in the past several decades is thought to be a result of people reducing many of the known dietary risk factors. This includes greater use of refrigeration for food storage rather than preservation of foods by salting, pickling, and smoking. To help reduce their risk, people should avoid diets that are high in smoked and pickled foods and salted meats and fish.

A diet high in fresh fruits and vegetables can also lower stomach cancer risk. Citrus fruits (such as oranges, lemons, and grapefruit) may be especially helpful. Grapefruit and grapefruit juice can cause the levels of certain drugs to go up, so it's important to discuss this with your health care team before adding grapefruit to your diet. The American Cancer Society recommends that people eat a variety of healthful foods, with an emphasis on those from plants. This includes eating at least 5 servings of vegetables and fruits each day, as well whole grain foods, and limiting intake of processed and red meats.

Studies that have looked at using dietary supplements to lower stomach cancer risk have had mixed results so far. There is some evidence that combinations of antioxidant supplements (vitamins A, C, and E and the mineral selenium) may reduce the risk of stomach cancer in people with poor nutrition to begin with. But most studies looking at people who have good nutrition have not found any benefit to adding vitamin pills to their diet. Further research in this area is needed.

Although some small studies suggested that drinking tea, particularly green tea, may help protect against stomach cancer, most large studies have not found such a link.

Obesity may add to the risk of stomach cancer. The American Cancer Society recommends maintaining a healthy weight throughout life by balancing calorie intake with physical activity. Aside from possible effects on the risk of stomach cancer, losing weight may also have an impact on the risk of several other cancers and health problems related to obesity.

Tobacco use can increase the risk of cancers of the proximal stomach (the portion of the stomach closest to the esophagus). Tobacco use increases the risk for many types of cancer and is responsible for about one third of all cancer deaths in the United States. If you don't use tobacco, please don't start. If you already do and want help quitting, call your health care professional or the American Cancer Society.

It is not yet clear whether antibiotic treatment should be given to people whose stomach linings are chronically infected with the bacteria H pylori but who do not have any symptoms. This is a topic of current research. Some early studies have suggested that giving antibiotics to people with H pylori infection may lower the number of pre-cancerous lesions in the stomach and may reduce the risk of developing stomach cancer. But not all studies have found this. More research needs to be done to be sure that this is a way to prevent stomach cancer in people with H pylori infection.

If your doctor thinks you might have H pylori infection, there are several ways of testing for this:

• The simplest way is a blood test that looks for antibodies to H pylori. Antibodies are proteins the body's immune system makes in response to an infection. A positive H pylori antibody test can mean either that an infection is present, or that there was an infection in the past that is now cleared.

• Another approach is to use endoscopy (see the section "How is stomach cancer diagnosed?") to take a biopsy of the stomach lining. This sample can be used for chemical tests for this kind of bacteria. Doctors can also identify H pylori in biopsy samples viewed under a microscope. The biopsy sample can also be cultured (placed in a nutrient medium that promotes growth of H pylori).

• There is also a special breath test for the bacteria. First you drink a liquid containing urea. If H pylori is present, it will cause chemical changes to the urea. A sample of your breath is then tested to detect these chemical changes.

Using aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen, seems to lower the risk of stomach cancer by at least 25%. These medicines can also lower the risk of developing colon polyps and colon cancer. But they can also cause serious (and even life-threatening) internal bleeding and other potential health risks in some people. Most doctors consider any reduced cancer risk an added benefit for patients who take these drugs for other reasons, such as to treat arthritis. But they do not routinely recommend NSAIDs specifically to prevent stomach cancer. Studies have not yet determined for which patients the benefits of lowering cancer risk would outweigh the risks of bleeding complications.

Avoiding risk factors when possible can lower a person's stomach cancer risk, but it cannot guarantee protection from this disease. Early detection may be the best way to improve the chance of successful treatment and reduce the number of deaths caused by the disease, particularly in countries where stomach cancer is common.

An inherited condition known as hereditary diffuse gastric cancer accounts for only a small percentage of stomach cancers, but it is very important to recognize. Because most people who have inherited this condition eventually get stomach cancer, people with a strong family history of stomach cancer should find out if they might have it. If their family history suggests that they do, genetic testing can be done at some cancer centers. If the result shows an abnormal form of the E-cadherin/CHD1 gene, many doctors will recommend they have their stomach removed before the cancer develops.

Last Medical Review: 11/03/2009
Last Revised: 11/03/2009