Risk Factors for Stomach Cancer
Risk Factors for Stomach Cancer
Anything that increases your chance of developing cancer is called a risk factor. Having one or more risk factors does not guarantee you will develop stomach cancer. It is also possible to develop stomach cancer without any known risk factors. Researchers continue to learn about the factors that make stomach cancer more or less likely to develop.
Most risk factors for stomach cancer are related to chronic inflammation of the stomach lining, damage to the stomach's protective cell layer, or inherited genetic changes that affect how cells grow and repair themselves.
THE BASICS: The most important risk factor for stomach cancer is long-term infection with Helicobacter pylori, commonly called H. pylori. Other significant risk factors include a diet high in salted, smoked, or pickled foods, smoking, a family history of stomach cancer, certain inherited syndromes, and chronic stomach conditions such as atrophic gastritis and intestinal metaplasia. Stomach cancer is also more common in men and in people over the age of 55.
What raises your risk of developing stomach cancer?
Helicobacter pylori infection. H. pylori is a bacterium that infects the stomach lining and is the single most important known cause of stomach cancer worldwide. It is estimated that H. pylori infection accounts for the majority of stomach cancer cases. Most people infected with H. pylori never develop stomach cancer, but long-term infection increases the risk by causing chronic inflammation, atrophic gastritis, and intestinal metaplasia.
Diet. A diet high in salt, salted fish, smoked meats, and pickled foods has been linked to a higher risk of stomach cancer. These foods may damage the stomach lining or promote the growth of H. pylori. A diet low in fresh fruits and vegetables, which provide protective antioxidants and vitamins, also raises the risk.
Smoking. Smokers have roughly twice the risk of developing stomach cancer compared to non-smokers. Tobacco smoke contains harmful chemicals that damage the cells of the stomach lining.
Family history of stomach cancer. People with a first-degree relative, meaning a parent, sibling, or child, who has had stomach cancer have a higher risk of developing the disease themselves. This may be due to shared H. pylori infection, shared dietary habits, or inherited genetic factors.
Hereditary diffuse gastric cancer syndrome. A rare inherited condition caused by mutations in the CDH1 gene. People with this syndrome have a very high lifetime risk of diffuse-type stomach adenocarcinoma and often require preventive surgery to remove the stomach. Mutations in other genes, including BRCA2, Lynch syndrome genes, and others, also raise the risk.
Previous stomach surgery. People who have had part of their stomach removed for non-cancer reasons have a higher risk of stomach cancer in the remaining stomach. Changes in stomach acid and bile flow after surgery may lead to chronic irritation.
Pernicious anemia. A condition in which the stomach cannot produce intrinsic factor, leading to vitamin B12 deficiency and chronic stomach inflammation. People with pernicious anemia have an elevated risk of stomach cancer.
Chronic atrophic gastritis. Long-term inflammation that causes thinning and loss of the normal glands in the stomach lining. It is often caused by H. pylori and is considered a precancerous condition.
Gastric polyps. Most stomach polyps are benign, but adenomatous polyps carry an increased risk of becoming cancerous and are usually removed when found.
Epstein-Barr virus infection. A small percentage of stomach cancers, about 5 to 10 percent, are associated with infection by the Epstein-Barr virus. These cancers tend to have specific molecular features and may respond differently to treatment.
Obesity. Being overweight or obese increases the risk of stomach cancer, particularly cancers that occur at the junction between the stomach and the esophagus.
Age, sex, and ethnicity. Stomach cancer is more common in men than in women, more common in people over the age of 55, and more common in people of East Asian, Eastern European, and Latin American descent. These differences are thought to be related to a combination of genetic, dietary, and H. pylori-related factors.
Occupational exposures. Working in coal mining, rubber or metal processing, or other industries with exposure to certain dusts and chemicals may slightly increase the risk of stomach cancer.
Factors that may lower your risk
Testing for and treating H. pylori. Treating H. pylori infection with antibiotics reduces inflammation and lowers the risk of stomach cancer. People with a family history of stomach cancer, chronic stomach symptoms, or precancerous stomach conditions should ask their doctor about testing for H. pylori.
Eating a healthy diet. A diet rich in fresh fruits and vegetables and low in salt, processed meats, smoked, and pickled foods is associated with a lower risk of stomach cancer. Foods high in vitamins C and E and other antioxidants may help protect the stomach lining.
Not smoking. Quitting smoking or never starting lowers the risk of stomach cancer and many other cancers.
Maintaining a healthy weight. Staying at a healthy weight reduces the risk of stomach cancer, particularly at the gastroesophageal junction.
Regular monitoring for people at high risk. People with known precancerous conditions such as intestinal metaplasia or dysplasia, or with a strong family history of stomach cancer, may benefit from regular endoscopic surveillance to find changes early.