Stomach Cancer Facts

April 28, 2025

This page was reviewed under our medical and editorial policy by Yanghee Woo, M.D., associate professor, Division of Surgical Oncology, Department of Surgery, City of Hope^® Orange County Lennar Foundation Cancer Center.

Approximately 17,720 men and 12,580 women are expected to be diagnosed with stomach cancer in 2025. This disease has become less prevalent in the United States over the past several decades, but it’s still a leading cause of cancer deaths in other countries.

What Is Stomach Cancer?

Stomach cancer — also called gastric cancer — is a disease affecting the stomach, an organ in the abdomen that’s shaped like a “J” and connects the esophagus to the intestines. It’s where food is partially digested before being passed through to the small intestine. It expands and contracts and has the capacity to hold a large volume of food and fluids.

What Causes Stomach Cancer?

Stomach cancer develops when the cells in the stomach change, or mutate, and divide uncontrollably. These cancerous cells then crowd out healthy cells, which may cause tumors.

Stomach Cancer Risk Factors

Things that may put people at higher risk for developing stomach cancer are called risk factors. Since the main role the stomach plays in the body is digesting food, an important risk for developing this type of cancer is related to what people eat.

Other things like genetics, age and whether the patient smokes also play a role. Some major risk factors for getting stomach cancer include those listed below.

Helicobacter pylori infection: Also called H. pylori, this condition is a type of bacterial infection affecting the inner lining of the stomach that can lead to inflammation (an immune system response that lingers for too long) and peptic ulcers. It is found in most stomach cancer patients.

Chronic atrophic gastritis: This creates problems in the immune system, causing it to attack cells in the stomach wall. This condition is related to H. pylori infection and may lead to cancer, but it is not known exactly how.

Intestinal metaplasia: This leads to changes to cells that line the stomach, so that they resemble cells in the intestine. This condition is suspected to play a role in stomach cancer.

Intestinal dysplasia: These are premalignant lesions that may transform into cancer over time if left untreated.

Diet: Those that are high in salted, pickled, fermented, smoked and preserved foods may raise the risk for developing stomach cancer.

Family history of gastric cancer: This may increase a person’s risk for developing the condition.

Genetic syndromes: Inherited conditions such as hereditary diffuse gastric cancer (caused by a mutation in a gene called CDH1), familial adenomatous polyposis, Li-Fraumeni syndrome, Lynch syndrome, juvenile-polyposis syndrome, Peutz-Jeghers syndrome, and hereditary breast and ovarian cancer syndrome may increase the risk of stomach cancer.

Other gastric cancer risk factors include:

Male gender: This is a stomach cancer risk factor — men are twice as likely as women to develop this cancer type.

Race and ethnicity: These factors may increase the risk of stomach cancer, especially for people who are Korean-American, African American, Hispanic or in another Asian group.

Certain medical conditions: Chronic atrophic gastritis, pernicious anemia, intestinal metaplasia and gastric polyps can increase the risk of stomach cancer.

Obesity or excess weight: Excess weight may increase the risk of stomach cancer.

Previous stomach surgery: Certain procedures, including having part of the stomach removed for reasons other than cancer, increases risk.

Industrial chemical exposure: Exposures that come from working in dusty and/or high temperature processing environments — or being exposed to certain chemicals like chromium — is associated with a higher risk for developing stomach cancer.

Smoking: Cigarettes and other tobacco products are linked to an increased risk of gastric cancer.

Blood type A: This blood type is associated with an increased risk of stomach cancer.

Age: Most people are diagnosed with stomach cancer in their late 60s or older

Stomach Cancer Prevention

Quitting smoking, maintaining a healthy weight and avoiding smoked, pickled, preserved and salted foods may lower a person’s risk for developing gastric cancer. Eating a diet rich in fruits and vegetables may also reduce risk and, as with many cancers, being physically active and avoiding processed foods and meats may help.

Studies are ongoing to find out if things like antibiotic treatment and eating an antioxidant-rich diet could thwart one of the biggest risks for stomach cancer: H. pylori.