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.
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:
To reduce your risk of developing stomach cancer:
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.