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Stomach Cancer

  • Posted: 10/15/2009

Risk Factors

When you're told that you have stomach cancer, it's natural to wonder what may have caused the disease. But no one knows the exact causes of stomach cancer. Doctors seldom know why one person develops stomach cancer and another doesn't.

Doctors do know that people with certain risk factors are more likely than others to develop stomach cancer. A risk factor is something that may increase the chance of getting a disease.

Studies have found the following risk factors for stomach cancer:

  • Helicobacter pylori infection: H. pylori is a bacterium that commonly infects the inner lining (the mucosa) of the stomach. Infection with H. pylori can cause stomach inflammation and peptic ulcers. It also increases the risk of stomach cancer, but only a small number of infected people develop stomach cancer. You may want to read the NCI fact sheet Helicobacter pylori and Cancer 1.
  • Long-term inflammation of the stomach: People who have conditions associated with long-term stomach inflammation (such as the blood disease pernicious anemia) are at increased risk of stomach cancer. Also, people who have had part of their stomach removed may have long-term stomach inflammation and increased risk of stomach cancer many years after their surgery.
  • Smoking: Smokers are more likely than nonsmokers to develop stomach cancer. Heavy smokers are most at risk.
  • Family history: Close relatives (parents, brothers, sisters, or children) of a person with a history of stomach cancer are somewhat more likely to develop the disease themselves. If many close relatives have a history of stomach cancer, the risk is even greater.
  • Poor diet, lack of physical activity, or obesity:
    • Studies suggest that people who eat a diet high in foods that are smoked, salted, or pickled have an increased risk for stomach cancer. On the other hand, people who eat a diet high in fresh fruits and vegetables may have a lower risk of this disease.
    • A lack of physical activity may increase the risk of stomach cancer.
    • Also, people who are obese may have an increased risk of cancer developing in the upper part of the stomach.

Most people who have known risk factors do not develop stomach cancer. For example, many people have an H. pylori infection but never develop cancer.

On the other hand, people who do develop the disease sometimes have no known risk factors.



Glossary Terms

bacteria (bak-TEER-ee-uh)
A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.
Helicobacter pylori (HEEL-ih-koh-BAK-ter py-LOR-ee)
A type of bacterium that causes inflammation and ulcers in the stomach or small intestine. People with Helicobacter pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma. Also called H. pylori.
infection (in-FEK-shun)
Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.
inflammation (IN-fluh-MAY-shun)
Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.
peptic ulcer (PEP-tik UL-ser)
A break in the lining of the lower part of the esophagus, the stomach, or the upper part of the small intestine. Peptic ulcers form when cells on the surface of the lining become inflamed and die. They are usually caused by Helicobacter pylori bacteria and by certain medicines, such as aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Peptic ulcers may be linked to cancer and other diseases.
pernicious anemia (per-NIH-shus uh-NEE-mee-uh)
A type of anemia (low red blood cell count) caused by the body's inability to absorb vitamin B12.
risk factor (... FAK-ter)
Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

Table of Links

1http://www.cancer.gov/cancertopics/factsheet/Risk/h-pylori-cancer