Optimal extent of lymphadenectomy for gastric adenocarcinoma: A 7-institution study of the U.S. gastric cancer collaborative.

BACKGROUND AND OBJECTIVES The optimal extent of lymphadenectomy in the treatment of gastric adenocarcinoma is debated. We compared gastrectomy outcomes following limited (D1) or extended (D2) lymphadenectomy. METHODS Using the multi-institutional US Gastric Cancer Collaborative database, we reviewed the morbidity, mortality, recurrence, and overall survival (OS) of patients receiving D1 or D2 lymphadenectomies. RESULTS Between 2000 and 2012, 266 and 461 patients received a D1 and D2 lymphadenectomy, respectively. ASA class, mean number of comorbidities, grade, and stage were similar between groups. While major morbidity was similar (P = 0.85), mortality was worse for those receiving a D1 lymphadenectomy (4.9% vs. 1.3%, P = 0.004). D2 lymphadenectomy was associated with improved median OS in stage I (4.7 years for D1 vs. not reached for D2, P = 0.003), stage II (3.6 years for D1 vs. 6.3 for D2, P = 0.42), and stage III patients (1.3 years for D1 vs. 2.1 for D2, P = 0.01). After adjusting for predictors of OS, D2 lymphadenectomy remained a significant predictor of improved survival (HR 1.5, 95%CI 1.1-2.0, P = 0.008). CONCLUSIONS D2 lymphadenectomy can be performed without increased risk of morbidity and mortality. Additionally, D2 lymphadenectomy is associated with improved survival especially in early stages, and should be considered for gastric adenocarcinoma patients. J. Surg. Oncol. 2016;113:750-755. © 2016 Wiley Periodicals, Inc.