Prognostic Value of Lymph Node Yield After Neoadjuvant Chemoradiation for Gastric Cancer

Background. Optimal lymphadenectomy (LAD) for gastric cancer (GC) after neoadjuvant chemoradiation (NACXRT) is not defined. This study assessed the prognostic value of LAD extent after modern preoperative therapy for GC. Methods. The study analyzed patients who underwent resection after NACXRT for GC at the authors' institution. Survival of the patients was compared between D1 and D2 resections and between lymph node (LN) yields (LNY) of fewer than 15 LNs and 15 or more LNs. The patients with early clinical nodal disease (cN0-1) were separately analyzed. Kaplan-Meier survival analyses were used to assess overall survival (OS) and disease-free survival (DFS). Results. Resection of GC was performed for 345 patients after NACXRT. Of these patients, 269 (78%) received a D2 resection, and 277 (80%) had an LNY of 15 LNs or more. There were no differences in length of stay (12[10-16] days vs. 12[10-15] days, p = 0.917) or in any major complication including leak rates, intraabdominal infections, and bleeding (all p[ 0.05). There was a significant difference in DFS (p = 0.050) and an OS trend (p = 0.085) based on D1 versus D2. Those who had 15 LNs removed showed a trend toward improved survival (DFS, p = 0.082; OS, p = 0.096). Among the patients with early clinical N stage disease (cN0-1), those who underwent D2 resections had better survival (DFS, p = 0.040; OS, p = 0.030). Conclusions. Patients with GC who underwent resection after NACXRT showed evidence of improved survival after an extended LAD, particularly those with early N stage disease. Perioperative morbidity did not differ based on extent of LAD. Despite the potential effects of tumor downstaging with preoperative therapy, a thorough locoregional lymphatic resection is recommended.