Stomach cancer risk factors: what raises the risk

Who gets stomach cancer

Stomach cancer is the fifth most common cancer worldwide. It is more common in East Asia, Western Asia, Eastern Europe and South America than in the United States and other Western countries (NCI risk factors).

Anyone can get it. In the United States it occurs more often among Black, Hispanic, Asian or Pacific Islander, and American Indian or Alaska Native people than among White people. Males are nearly twice as likely as females to be diagnosed with it. Rates have been rising in younger females, particularly Hispanic females (NCI risk factors). It can be diagnosed at any age, but the risk rises with age (NCI risk factors); two-thirds of people who have it are over age 65 (MedlinePlus).

H. pylori infection

Long-term (chronic) infection of the stomach lining with Helicobacter pylori (H. pylori) is a major risk factor for stomach cancer. The bacterium spreads from person to person through direct contact with saliva, vomit or stool. Many people with chronic infection have no symptoms, but some develop stomach ulcers or a stomach inflammation called atrophic gastritis, which in some people leads over time to stomach cancer or a type of lymphoma (NCI risk factors).

Treating H. pylori infection lowers the risk of these cancers (NCI risk factors). H. pylori raises the risk of cancer in the lower and middle parts of the stomach, while obesity and acid reflux (GERD) raise the risk in the upper stomach (NCI risk factors).

Other risk factors

• Smoking. People who smoke have a higher risk than nonsmokers. Smoking also makes H. pylori treatment less effective, and smokers who stop lower their risk over time (NCI risk factors). The quit smoking help check covers the help available.
• Diet. A diet low in fruits and vegetables, or high in salted, smoked or poorly preserved foods, may raise the risk (NCI risk factors). MedlinePlus names salted, smoked or pickled foods (MedlinePlus).
• Stomach conditions. Chronic atrophic gastritis (thinning of the stomach lining from long-term inflammation), atrophic gastritis with intestinal metaplasia (stomach lining cells replaced by cells like those of the intestine), and pernicious anemia (an autoimmune condition in which vitamin B12 is not absorbed properly) (NCI risk factors).
• Epstein-Barr virus infection (NCI risk factors).
• Obesity (NCI risk factors). The BMI calculator shows where your weight falls.
• Gastroesophageal reflux disease (GERD), where stomach acid repeatedly flows back into the esophagus (NCI risk factors). Long-lasting GERD is also linked to esophageal cancer.
• Work and radiation. Working in the rubber or coal industry, or past exposure to very high levels of radiation (NCI risk factors).

Family history and inherited syndromes

The risk is raised, sometimes to very high levels, in people who have (NCI risk factors):

• a parent, sibling or child who has had stomach cancer
• a family cancer syndrome, such as hereditary diffuse gastric cancer, familial intestinal gastric cancer, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), familial adenomatous polyposis, juvenile polyposis syndrome, Li-Fraumeni syndrome, Lynch syndrome or Peutz-Jeghers syndrome
• type A blood

Lynch syndrome also raises the risk of colorectal and endometrial cancer; see colorectal cancer risk factors and uterine cancer risk factors.

Having one or more risk factors does not mean you will get stomach cancer. Many people with risk factors never do, while others with no known risk factors do. NCI advises talking with your doctor if you think you might be at higher risk (NCI risk factors).

Symptoms to check with a doctor

Early stomach cancer usually has no symptoms, which makes it hard to find; symptoms usually begin after the cancer has spread (NCI symptoms). When early symptoms do occur, they may include (NCI symptoms):

• indigestion and stomach discomfort
• a bloated feeling after eating
• mild nausea
• loss of appetite
• heartburn

Advanced stomach cancer may also cause blood in the stool, vomiting, weight loss for no known reason, stomach pain, yellowing of the eyes and skin (jaundice), fluid buildup in the abdomen and trouble swallowing (NCI symptoms). Many conditions other than cancer cause these symptoms, but NCI says it is important to check with your doctor if you have any of them (NCI symptoms).

Screening: what NCI says

In the United States there are no standard or routine screening tests for stomach cancer in people at average risk (NCI screening). Some people at higher risk may benefit from screening with upper endoscopy, including older people with chronic gastric atrophy or pernicious anemia, people who have had part of the stomach removed (partial gastrectomy), people with a family history of stomach cancer or certain genetic syndromes, and people from countries where stomach cancer is more common (NCI screening). Talk with your doctor about whether screening is right for you (NCI screening).

All cancer checks are on the cancer screening hub.

Common questions

Does H. pylori always lead to stomach cancer?

No. Many people with chronic H. pylori infection have no symptoms, and only some develop the stomach changes that can lead to cancer. Treating the infection lowers the risk (NCI risk factors).

Which foods raise stomach cancer risk?

NCI says a diet high in salted, smoked or poorly preserved foods, or low in fruits and vegetables, may raise the risk (NCI risk factors). MedlinePlus lists eating lots of salted, smoked or pickled foods (MedlinePlus).

Does alcohol raise stomach cancer risk?

Alcohol is not on NCI's list of stomach cancer risk factors, and MedlinePlus does not list it either (NCI risk factors) (MedlinePlus). NCI's separate fact sheet on alcohol and cancer says some evidence suggests a link with stomach cancer; the alcohol and cancer risk guide covers that and the cancers alcohol is known to cause.