GASTRIC-CANCER

Despite the decline in the incidence of gastric cancer in Western coun tries over the past four decades, adenocarcinoma of the proximal stoma ch and gastroesophageal junction are increasing steadily. Although lit tle is known about the etiologic factors responsible for the increased incidence of these tumors, recent studies have identified molecular a lterations in gastric cancers including mutations in oncogenes, tumor suppressor genes, and genes involved in cellular adhesion processes. R educed expression and mutation of the cell adhesion molecule, E-cadher in, has been found in gastric cancers and may underlie their tendency toward invasion and metastasis. The carbohydrate-associated antigen si alosyl-Tn antigen has been shown to be of prognostic value in colon ca ncer and its role in the clinical behavior of gastric cancers is under evaluation. Interesting data on the use of chemopreventive agents hav e been obtained from a nutritional intervention trial in Linxian, Chin a. Linxian has one of the highest rates of esophageal and gastric card ia cancer in the world and dietary deficiencies in vitamins and minera ls are believed to contribute to cancer causation in this population. Regarding the treatment of local-regional gastric cancer, there is con tinued interest in combined pre- and postoperative chemotherapy in an effort to downstage disease prior to resection. However, more efficaci ous regimens are needed before the theoretical benefits of this approa ch can be fully realized. Chemotherapy for advanced disease remains ex perimental and current approaches aim to maximize existing regimens wh ile the search for new agents continues.