Adenocarcinoma Is Common
The vast majority of gastric cancers, up to 90% to 95% of all stomach cancers, are adenocarcinomas. These cancers arise from secretory cells in the stomach lining that produce mucus and other fluids. This layer is called the mucosa. Several risk factors predispose individuals to this type of malignancy. Diet, family history, inflammation, polyps, pernicious anemia, and smoking may all play a role in this kind of cancer. It occurs most commonly in men over the age of 40. People from certain regions of eastern Europe, Asia, and South America are also at greater risk.