1) Clinico-pathologic Considerations

Almost all gastric cancers are adenocarcinomas, with lymphoma, carcinoid, gastrointestinal stromal tumours and other rare malignancies comprising the remainder. The pattern of presentation of gastric cancer has been changing over the past several decades. Since 1950, there has been a progressive shift in the proportion of proximal gastric adenocarcinomas, such that about 1/3 of gastric cancer presents in the proximal stomach. About 15% of cases will present as "linitis plastica", a diffuse disease which tends to involve the entire stomach. About 5-10% of cases will now present as expansive-type or superficial gastric cancer, which is much more amenable to surgical cure if there is no distant spread.

2) Classification Criteria

Gastric adenocarcinoma may be sub-classified into intestinal type or diffuse type, based upon the histologic appearance. Patients with diffuse cancers tend to do worse, likely related to more advanced stage at diagnosis. Management is based upon clinical staging of the disease.