The effect of extended lymphadenectomy on survival in patients with gastric adenocarcinoma.

BACKGROUND: In the United States of America, the five-year survival rate among patients surviving curative resection for gastric carcinoma will range between 20 and 25 percent. In Japan, early diagnosis and an aggressive surgical approach including planned lymph node dissection has resulted in the five-year survival rate exceeding 50 percent for all patients with newly diagnosed gastric carcinoma. This report is a retrospective review evaluating the effect of extended lymph node dissection (D2) on overall survival in 101 patients with gastric adenocarcinoma who underwent a potentially curative gastric resection from 1975 to 1990 at Roswell Park Cancer Institute.

STUDY DESIGN: Gastric carcinomas were staged according to the revised 1987 TNM classification. Lymph node dissections were defined according to the General Rules of the Japanese Research Society for Gastric Cancer. Gastric resections in this study were classified as D2.5, D2, D1.5, and D1 and divided into two groups, the extended resection group (D2, D2.5) and the limited resection group (D1, D1.5).

RESULTS: The median follow-up period was 33 months. The entire group (n = 101) had an estimated five-year survival rate of 36 percent with a median survival rate of 33 months. The estimated five-year survival rate for the extended resection group (n = 46) was 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 gastric carcinoma survived five years, 75 percent of patients with stage 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 extended resection, with 44 percent surviving five years with a median of 43 months compared with 16 percent and 25 months, respectively, for patients undergoing a limited resection (p = 0.05). Of 13 patients treated with a D2 or greater resection whose gastric carcinomas metastasized to N2 lymph nodes, four patients (31 percent) survived at least five years. Only the extent of lymph node dissection and type of gastric resection proved to be significant independent predictors of overall survival.

CONCLUSIONS: Patients treated by extended resection (D2, D2.5) were more likely to survive five years and had prolonged median survival 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 approaching statistical significance.