POTENTIALLY RESECTABLE GASTRIC-CARCINOMA - CURRENT APPROACHES TO STAGING AND PREOPERATIVE THERAPY

The incidence of gastric carcinoma has declined worldwide during the p ast several decades, and yet this cancer remains the most common malig nancy in several countries around the world, particularly Japan, Chile , and Costa Rica. Gastric carcinoma, although not as common in the Uni ted States as it was in the past, is still the eighth most frequent ca use of cancer death. For patients with localized gastric carcinoma, su rgery remains the most effective therapy, resulting in a consistent bu t low rate of cure. Unresectable gastric carcinoma is an incurable dis ease with the exception of a small fraction of patients who are salvag ed with chemoradiotherapy. In Western countries curative resection rat es have been dismal because of the lack of early diagnosis. Additional ly, postoperative adjuvant strategies in the United States and Europe have been ineffective. Even patients with curative resection frequentl y develop intraperitoneal and systemic carcinoma in addition to locore gional relapses. Many investigators have therefore embarked on the the rapeutic strategies of preoperative chemotherapy and postoperative int raperitoneal chemotherapy. The preoperative chemotherapy strategy has particular appeal because of its potential to reduce the size of the p rimary tumor, thereby allowing a higher rate of curative resection; ea rly systemic therapy of micrometastates might prove biologically more effective. To date, several studies using preoperative chemotherapy ha ve demonstrated its feasibility. The effectiveness of repeated courses of postoperative intraperitoneal chemotherapy remains unsettled mainl y owing to the inadequacy of peritoneal drug distribution and the asso ciated toxic effects. Additional investigations are necessary to impro ve preoperative staging with the use of endoscopic ultrasonography and laparoscopy (peritoneal staging). More effective preoperative chemoth erapy combinations that might lead to 5% to 10% complete pathologic re sponse in the presence of modest toxicity must be established prior to launching large-scale trials. The impact of these novel strategies on resection rates, failure sites, and patients' survival can be determi ned only by carefully designed, controlled clinical trials.