Prognostic role of lymphocyte-to-monocyte ratio in pancreatic neuroendocrine neoplasms

Systemic inflammation markers have been demonstrated to be associated with prognosis in various tumors. In this study, we aimed to assess the value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index and the counts of lymphocyte, monocyte and neutrophil in predicting prognosis among patients with resected pancreatic neuroendocrine neoplasms (pNENs).A total of 174 patients were included in the study. Univariate and multivariate analyses were performed to evaluate the predictive roles of inflammation markers for relapse-free survival (RFS) and overall survival (OS) in pNEN patients.The optimal cut-off values of NLR, LMR and lymphocyte count were 1.9, 5.0 and 1.4 × 109/L, respectively, determined by the X-tile software. RFS was found to be significantly longer in patients with NLR ≤1.9 (P= 0.041), LMR >5.0 (P< 0.001) and lymphocyte count >1.4 × 109/L (P= 0.002) in comparison to those with NLR >1.9, LMR ≤5.0 and lymphocyte count ≤1.4 × 109/L, respectively. Multivariate analysis revealed that LMR (hazard ratio 0.30, 95% CI 0.11–0.85, P= 0.023) was an independent predictor for RFS, but not NLR or lymphocyte count. For long-term survival analysis, patients with NLR ≤1.9 (P= 0.016) were found to be associated with favorable OS, but NLR was not an independent factor validated by multivariate analysis.Preoperative LMR is an independent systemic inflammation marker to predict relapses in pNEN patients who underwent curative resections, whose clinical value needs to be verified in further large sample-based prospective studies.