A risk factor is something that increases the chance of having a certain health condition. Different cancers have different risk factors. The exact cause of stomach cancer is not known. But certain factors can make it more likely for you to have stomach cancer.
Age, sex, race, blood type
Age. Stomach cancer is more likely in people older than 50. Most people with stomach cancer are in their late 60s or older.
Sex. Stomach cancer is more common in men.
Race. In the U.S., stomach cancer is more common in Hispanics, African Americans, Asians, and Pacific Islanders.
Blood type. People with the blood type A have an increased risk for stomach cancer.
Diet. Some foods are linked to stomach cancer. These include smoked, salted, pickled, and cured foods.
Smoking. Smoking increases the risk for stomach cancer.
Overweight and obesity. Being overweight or obese may increase the risk for stomach cancer.
Some health conditions increase the risk for stomach cancer. They include:
Helicobacter pylori (H. pylori) infection. H. pylori is a bacterium that causes many cases of stomach ulcers. Long-term infection with H. pylori is also a major risk factor for stomach cancer.
Previous stomach surgery. Having part of your stomach removed for reasons other than cancer increases the risk for stomach cancer.
Pernicious anemia. People with this condition are not able to absorb vitamin B12, and they have low red blood cell levels (anemia). This can lead to an increased risk for stomach cancer.
Stomach polyps. A type of growth or polyp called adenoma can occur in the stomach. Having these raises your risk for stomach cancer.
A toxic workplace. People who work in the coal, metal, and rubber industries are at increased risk. This may be because of toxic dust and fumes that are inhaled.
Having family members with certain conditions increases the risk for stomach cancer. Some of the conditions include:
Stomach cancer in parents, brothers, sisters, or children
Hereditary nonpolyposis colorectal cancer
Familial adenomatous polyposis
Breast cancer gene mutations BRCA1 and BRCA2
Some risk factors, such as family history, are not within your control. But you can control other risk factors, such as diet and smoking. You may be able to lower your risk for stomach cancer if you:
Stop smoking. If you need help, talk with your health care provider. Many resources are also available in your community and on the Internet. You can get resources for quitting at www.smokefree.gov. Or call 800-QUIT-NOW.
Avoid certain foods. Not eating smoked, salted, pickled, or cured foods may lower your risk.
Maintain a healthy weight. If you are overweight, talk with your health care provider about how to lose weight. If you are at a healthy weight, stay there. Eat fruits, vegetables, and whole grains every day.
Talk with your health care provider if you have a family history of stomach cancer. Talk with him or her about your risk factors. Your health care provider may advise you to have regular health exams or certain tests.