Causes, Risk Factors, and Prevention of Stomach Cancer

There is no clear indicator as to what causes stomach (gastric) cancer. Stomach cancer occurs when cells in your stomach develop errors, known as mutations, in their DNA. These mutations make cells grow and divide out of control. These abnormal cells accumulate, forming a tumor in the stomach that can metastasize (spread) to other parts of the body such as the liver, peritoneum, lungs, and bones. 

Stomach Cancer Risk Factors

While the cause of stomach cancer is uncertain, there are various factors that can increase your risk of developing the disease. These risk factors can include: 

  • Tobacco use
  • Eating a diet high in salty and smoked foods
  • Not eating enough fruits and vegetables
  • Family history of stomach cancer
  • Stomach polyps 
  • Pernicious anemia (a condition in which the body can't make enough healthy red blood cells because it doesn't have enough vitamin B12)
  • Infection with Helicobacter (H) pylori
  • Long-term stomach inflammation

Reducing Your Risk of Stomach Cancer

To reduce your risk of developing stomach cancer: 

  • Quit smoking
  • Increase the amount of fruits and vegetables in your diet
  • Avoid a diet that is high in smoked and pickled foods and salted meats and fish
  • Maintain a healthy weight

A small percentage of stomach cancers are known to be caused by hereditary diffuse gastric cancer syndrome. If you have a personal history of invasive lobular breast cancer before age 50 or have close family members who have had stomach cancer, you may choose to talk with a genetics professional about getting tested for the CDH1 gene mutation. Another hereditary cancer syndrome with an increased risk for stomach cancer is Lynch syndrome.