Studies have implied that diet and other environmental factors are the reason for this change. For example, according to the National Cancer Institute, stomach cancer can be induced in laboratory animals by feeding them large amounts of nitrates and nitrites, compounds that occur in certain foods and which also are used to make bacon and other cured meats. The American Cancer Society indicates that stomach cancer occurs twice as often in men as women and is rarely seen in persons under the age of forty. A family history of stomach cancer also increases the risk, as does inflammation of the stomach.
Stomach cancers cause few symptoms in their early stage.
Later, symptoms are often similar to those of an ulcer or may include vague feelings of fullness, loss of appetite, and indigestion. Signs of more advanced stomach cancer include weight loss, vomiting, throwing up blood, pain, difficulty swallowing, blood in the stool or a change in bowel habits, and a lump or mass that can be felt in the abdomen. It is recommended that you see a doctor if stomach pains last for more than two weeks, or if you have any other symptoms of stomach cancer.