Lymphocyte-to-monocyte ratio predicts survival of patients with hepatocellular carcinoma after curative resection

Aim: To investigate the prognostic value of preoperative lymphocyte-to-monocyte ratio (LMR) in patients with hepatocellular carcinoma (HCC) undergoing curative hepatectomy.

Methods: Clinicopathological data of 210 hepatitis B virus (HBV)-associated HCC patients who were treated by radical hepatic resection between 2003 and 2010 were retrospectively analyzed. None of the patients received any preoperative anticancer therapy or intraoperative radiofrequency ablation. The diagnosis was confirmed by pathological examination after surgery. Absolute peripheral blood lymphocyte and monocyte counts were derived from serum complete blood cell count before surgery, and LMR was calculated by dividing lymphocyte count by monocyte count. The best cutoff was determined by receiver operating characteristics (ROC) curve analysis. Correlations between LMR levels and clinicopathological features were assessed using the χ(2) test. Survival outcomes were estimated using the Kaplan-Meier method and compared by the log-rank test. Univariate and multivariate analyses were performed to evaluate the prognostic impact of LMR and other clinicopathological factors on overall survival (OS) and recurrence-free survival (RFS), using the Cox proportional hazards model.

Results: The optimal cutoff value of LMR for survival analysis was 3.23, which resulted in the most appropriate sensitivity of 55.3% and specificity of 74.7%, with the area under the curve (AUC) of 0.66 (95%CI: 0.593-0.725). All patients were dichotomized into either a low (≤ 3.23) LMR group (n = 66) or a high (> 3.23) LMR group (n = 144). A low preoperative LMR level was significantly correlated with the presence of cirrhosis, elevated levels of total bilirubin and larger tumor size. Patients with a low LMR level had significantly reduced 5-year OS (61.9% vs 83.2%, P < 0.001) and RFS (27.8% vs 47.6%, P = 0.009) compared to those with a high LMR level. Multivariate analyses indicated that a lower LMR level was a significantly independent predictor of inferior OS (P = 0.003) and RFS (P = 0.006). Subgroup analysis indicated that survival outcome was significantly more favorable in cirrhotic patients with LMR > 3.23. However, there were no differences between low and high LMR groups for OS and RFS in non-cirrhotic patients.

Conclusion: Preoperative LMR was demonstrated for the first time to serve as an independent prognostic factor in HBV-associated HCC patients after curative resection. Prospective studies with larger cohorts for validation are warranted.