Lymphadenectomy in patients with gastric cancer. A critical review.

BACKGROUND: Surgical resection is still the main treatment for patients with gastric cancer. However, while surgical procedures for the treatment of the primary tumor have been standardized, there has been no worldwide consensus as yet on the extent of lymphadenectomy. The aim of the present study was therefore to evaluate the outcome following extended lymphadenectomy, and the prognostic significance of lymph node status, in a group of patients who underwent radical resection for gastric cancer. METHODS: Among 445 consecutive patients operated on for gastric adenocarcinoma between 1980 and 2000 at Clinica Chirurgica II of the Padua University, 314 underwent radical resection (R0). A D2 lymphadenectomy was performed in 293/314 cases (93.3%), and a D1 in 21/314 (6.7%). The rate of postoperative morbidity was 22% (69/314 patients), and the postoperative mortality (within 30 days of surgery), 4.1% (13/314 patients). Survival was determined using the Kaplan Meier method and differences were assessed by the log-rank test. Multivariate analysis was performed using the Cox proportional hazards model in forward stepwise regression. RESULTS: Of 301 valuable patients, a total of 7991 lymph nodes were examined (mean, 27.18; range, 9-62) and the total number of metastatic lymph nodes was 1343 (mean, 4.5; range, 1-47). After a median follow-up of 49 months (range, 2-251), the overall 5-year survival was 57%. At multivariate analysis of all 301 patients, factors retained were depth of invasion (P < 0.001), age (P = 0.027), number of lymph node metastasis (P = 0.029), and metastatic/examined lymph node ratio (P < 0.0001). CONCLUSIONS: D2 dissection can be performed without incurring high mortality and morbidity rates. At least 15 lymph nodes must be removed to achieve an accurate disease staging. As confirmed at multivariate analysis, a metastatic/examined lymph node ratio greater than 25% is an independent negative prognostic factor.