Association Between Lymph Node Ratio and Survival in Patients with Pathological Stage II/III Gastric Cancer.

Lymph node ratio (LNR), defined as the ratio of metastatic nodes to the total number of examined lymph nodes, has been proposed as a sensitive prognostic factor in patients with gastric cancer (GC). We investigate its association with survival in pathological stage (pStage) II/III GC and explore whether this is a prognostic factor in each Union for International Cancer Control pStage (7th edition). We retrospectively examined 838 patients with pStage II/III GC who underwent curative gastrectomy between June 2000 and December 2018. Patients were classified into low-LNR (L-LNR), middle-LNR (M-LNR), and high-LNR (H-LNR) groups according to adjusted X-tile cutoff values of 0.1 and 0.25 for LNR, and their clinicopathological characteristics and survival rates were compared. The 5-year recurrence-free survival (RFS) and overall survival (OS) rates postsurgery showed significant differences among the groups (P < 0.001). Multivariate analysis demonstrated that LNR was a significant predictor of poor RFS [M-LNR: hazard ratio (HR) 3.128, 95% confidence interval (CI) 2.254–4.342, P < 0.001; H-LNR: HR 5.148, 95% CI 3.546–7.474, P < 0.001] and OS (M-LNR: HR 2.749, 95% CI 2.038–3.708, P < 0.001; H-LNR: HR 4.654, 95% CI 3.288–6.588, P < 0.001). On subset analysis stratified by pStage, significant differences were observed between the groups in terms of the RFS curves of pStage II and III GC (P < 0.001 and < 0.001, respectively) and OS curves of pStage II and III GC (P = 0.001 and < 0.001, respectively). High LNR is a predictor of worse prognosis in pStage II/III GC, including each substage.