Stomach is located in the upper left of the abdomen. Tumors may grow from mucosa membrane of the stomach due to various reasons to be mentioned in reasons section. Malignant tumors cause cancer. Stomach cancer often occurs on small curvature of the stomach. Stomach cancer is the 4th most frequent cancer type. In Turkey, approximately twenty thousand persons get stomach cancer annually. Risk of stomach cancer is higher in men. Stomach cancer is more frequent in elderly.

Large intestine, also called colon, is about 2 meters long and comes after small intestines in digestive system. Colon cancer, which is frequently encountered especially in western countries, is of great significance. Incidence of colon cancer within the population is around 5 in 10000. Colon cancer risk is equal in men and women, and colon cancer is the 3rd most frequently seen cancer type.