Stomach cancer often begins at a site where the stomach lining is inflamed or irritated. However, many experts argue that inflammation is the result of stomach cancer, not its cause.
Some studies have suggested that stomach ulcers can lead to cancer, but other experts believe most people with ulcers and stomach cancer probably had an undetected cancer before the ulcers developed.
Stomach polyps are thought to be forerunners of cancer and are removed as a precaution. Cancer is increasingly likely with certain types of polyp, a polyp larger than ? inch, or when a number of polyps are present.
Medical conditions that may contribute to stomach cancer include:
Two types of anemia (megaloblastic anemia and pernicious anemia).
Partial removal of the stomach (gastrectomy) .
A stomach disorder called atrophic gastritis, or Menetrier's disease.
Environmental Factors
Exposure to certain dusts, molds, fumes, and other environmental agents at home or in the workplace has been linked to a higher than average risk of stomach cancer.
Some experts believe that smoking might increase stomach cancer risk.
Infection
Helicobacter pylori bacteria associated with duodenal ulcers, has been implicated in stomach cancers.
Diet
Some dietary factors are believed to play a role in the development of stomach cancer. If followed over a long period of time, these dietary practices may increase your risk. These include:
A high salt intake.
High intake of preservatives called nitrates, which are found in salted, pickled, or smoked foods.
A low intake of green leafy vegetables and fruit.