Preoperative lymphocyte-to-monocyte ratio as a strong predictor of survival and recurrence for gastric cancer after radical-intent surgery

OBJECTIVES To evaluate the predictive value of the preoperative lymphocyte-to-monocyte ratio (LMR) for the prognosis of patients with gastric cancer (GC) after radical-intent surgery. METHODS We retrospectively analyzed 1,810 patients who underwent radical-intent gastrectomy for primary GC from December 2008 to December 2013. X-tile software was used to identify the optimal value for blood LMR. Nomograms were developed to predict overall survival (OS) and recurrence-free survival (RFS) after surgery. RESULTS LMR was significantly lower in patients with GC than in matched normal volunteers (P<0.001). As shown by forest plots, the long-term outcomes were poorer in the low LMR group than in the high LMR group when considering subgroups separated by clinical characteristics. Cox regression analysis showed that LMR was an independent prognostic factor for OS (P<0.001) and RFS (P=0.001). Nomograms, combining LMR with age, T stage, and N stage, showed better discriminative abilities than the AJCC staging system did in predicting 5-year survival and recurrence from the time of surgery. The recurrence rate was 30.4% (550/1810) and was significantly higher in the low LMR group than in the high LMR group (P<0.05). The LMR was also closely correlated with liver and lymph node metastases (both P<0.05). CONCLUSION As an independent prognostic factor for GC, preoperative LMR can improve the predictability of individual survival and recurrence. Furthermore, because liver and lymph node metastases were more commonly observed in patients with low blood LMR before surgery, these patients should be closely followed after the operation.