Stomach Cancer Causes

Although experts haven’t identified the exact causes of gastric cancer, research has uncovered a number of stomach cancer risk factors. These include age and ethnicity, along with health history and a variety of lifestyle factors.

Cancer risk factors are things that can increase one’s risk of developing cancer. However, it’s important to understand that having risk factors doesn’t mean you’ll get cancer of the stomach, just as some people who aren’t at risk for the disease can develop this type of cancer.

Stomach Cancer Risk Factors: Demographics

First, let’s look at the demographics of stomach cancer. More men than women develop stomach cancer, and most stomach cancer occurs in people over the age of 70, according to the National Cancer Institute (n.d.).

Gastric cancer is most common in people of Asian or Pacific Island descent. Stomach cancer is relatively rare in the United States, and Japan has the world’s highest rate of stomach cancer.

Stomach cancer is also found in increased rates in people who work in the coal, metal and rubber industries, though this link is unclear.

Stomach Cancer Risk Factors: Diet

Diet is a factor in many diseases. A heavy diet of smoked, salted or pickled foods appears to increase the risk of stomach cancer, possibly due to high levels of nitrates and nitrites that naturally-occurring bacteria in the stomach can convert into cancer-causing compounds. As the use of refrigeration for preserving foods has increased, stomach cancer rates have declined, according to the Mayo Clinic (2009). Also, eating a diet with lots of fresh fruits and vegetables may lower the risk of the disease.

Stomach Cancer Risk Factors: Stomach Health

Helicobacter pylori (“H. pylori”) is a type of bacteria that can infect the stomach. H. pylori can cause stomach inflammation and lead to a peptic ulcer. Between 2 and 20 percent of people infected with H. pylori will develop a peptic ulcer, according to the National Cancer Institute (n.d.). According to some studies, the presence of H. pylori appears to increase the risk of stomach cancer.

In addition, atrophic gastritis and intestinal metaplasia are two conditions that appear to be pre-cancerous. In cases of atrophic gastritis, the stomach has either decreased or absent normal glands and inflammation. In cases of intestinal metaplasia, the normal lining of the stomach is replaced with cells that closely resemble the cells that usually line the intestine. However, neither condition is well understood.

Stomach Cancer Risk Factors: Smoking

Smoking is a major risk factor for stomach cancer. If you quit smoking, you are less likely to get stomach cancer.

Other Stomach Cancer Risk Factors

Other gastric cancer risk factors include:

  • Heavy alcohol use
  • Family history of stomach cancer
  • Inherited conditions, such as hereditary diffuse gastric cancer, hereditary non-polyposis colorectal cancer, familial adenomatous polyposis (FAP), and the presence of the inherited breast cancer genes BRCA1 and BRCA2
  • Obesity may increase the risk of cancer of the stomach in the upper part of the stomach (cardia), but the strength of this link isn’t yet clear.
  • Pernicious anemia (vitamin B12 deficiency)
  • Stomach polyps, which are usually benign growths on the stomach lining, although some polyps can develop into cancer
  • Stomach surgery to remove part of the stomach to treat non-cancerous conditions, such as an ulcer, is linked to increased rates of stomach cancer.

Researchers continue to investigate stomach cancer causes. If you’re concerned about your risk of developing gastric cancer, talk to your healthcare provider.


American Cancer Society. (2010). Stomach cancer. Retrieved February 7, 2011, from

Mayo Clinic. (2009). Stomach cancer. Retrieved February 7, 2011, from

National Cancer Institute. (2006). H. pylori and cancer: Fact sheet. Retrieved February 7, 2011, from

National Cancer Institute. (n.d.). Stomach (gastric) cancer. Retrieved February 7, 2011, from