THE EFFECT OF EXTENDED LYMPHADENECTOMY ON SURVIVAL IN PATIENTS WITH GASTRIC ADENOCARCINOMA

BACKGROUND: In the United States of America, the five-year survival ra te among patients surviving curative resection for gastric carcinoma w ill range between 20 and 25 percent. In Japan, early diagnosis and an aggressive surgical approach including planned lymph node dissection h as resulted in the five-year survival rate exceeding 50 percent for al l patients with newly diagnosed gastric carcinoma. This report is a re trospective review evaluating the effect of extended lymph node dissec tion (D2) on overall survival in 101 patients with gastric adenocarcin oma who underwent a potentially curative gastric resection from 1975 t o 1990 at Roswell Park Cancer Institute. STUDY DESIGN: Gastric carcino mas were staged according to the revised 1987 TNM classification. Lymp h node dissections were defined according to the General Rules of the Japanese Research Society for Gastric Cancer. Gastric resections in th is study were classified as D2.5, D2, D1.5, and D1 and divided into tw o groups, the extended resection group (D2, D2.5) and the limited rese ction group (D1, D1.5). RESULTS: The median follow-up period was 33 mo nths. The entire group (n=101) had an estimated five-year survival rat e of 36 percent with a median survival rate of 33 months. The estimate d five-year survival rate for the extended resection group (n=46) tvas 49 percent with a median of 50 months compared with 27 percent and 25 .7 months, respectively, for the limited resection group (n=55, p=0.01 ). Following extended resection, 74 percent of patients with stage I g astric carcinoma survived five years, 75 percent of patients with stag e II carcinoma were alive at five years as were 13 percent with stage IIIA, and 30 percent with stage IIIB. Patients whose tumors fell into the classifications of T2-4, N0-1, M0 and required a total or proximal gastrectomy enjoyed a significant survival advantage undergoing an ex tended resection, with 44 percent surviving five years with a median o f 43 months compared with 16 percent and 25 months, respectively, for patients undergoing a limited resection (p=0.05). Of 13 patients treat ed with a D2 or greater resection whose gastric carcinomas metastasize d to N2 lymph nodes, four patients (31 percent) survived at least five years. Only the extent of lymph node dissection and type of gastric r esection proved to be significant independent predictors of overall su rvival. CONCLUSIONS: Patients treated by extended resection (D2, D2.5) were more likely to survive five years and had prolonged median survi val times when compared with patients treated with Limited resection ( D1, D1.5). For patients with T2-4, N0-1, M0 gastric carcinomas treated with extended resection, their differences reached levels at or appro aching statistical significance.