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

Objectives: 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).

Methods: 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.

Results: 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.

Conclusions: 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.