Gastric cancer

Despite the decline in the incidence of gastric cancer in Western countries over the past four decades, adenocarcinoma of the proximal stomach and gastroesophageal junction are increasing steadily. Although little is known about the etiologic factors responsible for the increased incidence of these tumors, recent studies have identified molecular alterations in gastric cancers including mutations in oncogenes, tumor suppressor genes, and genes involved in cellular adhesion processes. Reduced expression and mutation of the cell adhesion molecule, E-cadherin, has been found in gastric cancers and may underlie their tendency toward invasion and metastasis. The carbohydrate-associated antigen sialosyl-Tn antigen has been shown to be of prognostic value in colon cancer and its role in the clinical behavior of gastric cancers is under evaluation. interesting data on the use of chemopreventive agents have been obtained from a nutritional intervention trial in Linxian, China. Linxian has one of the highest rates of esophageal and gastric cardia cancer in the world and dietary deficiencies in vitamins and minerals are believed to contribute to cancer causation in this population. Regarding the treatment of local-regional gastric cancer, there is continued interest in combined pre- and postoperative chemotherapy in an effort to downstage disease prior to resection. However, more efficacious regimens are needed before the theoretical benefits of this approach can be fully realized. Chemotherapy for advanced disease remains experimental and current approaches aim to maximize existing regimens while the search for new agents continues.