Prognostic and predictive value of metastatic lymph node ratio in stage III gastric cancer after D2 nodal dissection

Introduction: This study is to evaluate the prognostic and predictive value of metastatic lymph node ratio (MLR) in stage III gastric cancer following radical D2 dissection.

Methods: 87 patients who underwent radical resection with D2 lymphadenectomy were retrospectively evaluated. The median age was 60 with a 2:1 ratio of male/female. Of these 87 patients, 83 underwent total gastrectomy, the remaining 4 underwent subtotal gastrectomy and 57 patients received adjuvant chemotherapy with fluoropyrimidines. Indexes of lymph node involvement and other clinicopathological data were analyzed. Survival was determined by the Kaplan-Meier method and log-rank test. Multivariate analysis was performed using the Cox proportional hazards model.

Results: Median total retrieved lymph node number was 35 (range: 10-104) with median metastatic lymph node amount of eight (range: 0-71). Median survival time was 31.7 months with a 3-year survival rate of 36.4%. Patients were divided into four groups according to MLR: MLR0, 0; MLR1, <0.1; MLR2, 0.1-0.25; MLR3, >0.25. After median follow-up of 31 months, median OS rates of MLR0 to MLR3 were 37.1m, 35.9m, 31.5m and 20.8m, respectively (p=0.013). Median OS rates were significantly different among subgroups: 39.3m and 36.5m were obtained for low subgroups (MLR<0.24) with or without adjuvant chemotherapy, respectively; 22.9m and 12.2m were found in high subgroups (MLR>0.24) with and without chemotherapy, respectively (p=0.002). Finally, MLR constituted an independent prognostic factor in multivariable analysis.

Conclusions: After R0 resection with D2 lymphadenectomy for stage III gastric cancer, MLR constitutes an effective prognostic indicator. Patients with high MLR may benefit the most from adjuvant chemotherapy.