Prognostic role of the lymphocyte-to-monocyte ratio for clinical outcomes of patients with progressive radioiodine-refractory differentiated thyroid carcinoma treated by sorafenib

Objectives: The lymphocyte-to-monocyte ratio (LMR) reflects the status of tumour-infiltrating immune cells and host immunity. The LMR has been reported as a prognostic marker in various cancers. The present study evaluated the role of the LMR as a prognostic marker in patients with progressive radioiodine-refractory (RAIR) differentiated thyroid carcinoma (DTC). Design: Retrospective cohort study. Patients: Forty patients with progressive RAIR DTC who were treated by sorafenib with available baseline complete blood cell count data. Measurements: We assessed the response rate, progression-free survival (PFS) and overall survival (OS). Results: The patients were divided into low and high LMR groups based on their baseline LMRs (<4, n = 22, 55% and >= 4, n = 18, 45%, respectively). There were no significant differences in baseline characteristics between the groups. The OS curves differed significantly based on the LMR. The median OS of the low LMR group was 24.3 months and that of the high LMR group was not reached until the end of observation period (P = .015). The PFS curves and median PFS also differed significantly based on the LMR values (P = .019). In multivariate analysis, low LMR was an independent risk factor for all-cause mortality in patients with progressive RAIR DTC (hazard ratio, 2.64; 95% confidence interval: 1.04-6.72, P = .041). Conclusion: A low LMR was associated with poor response rate, PFS and OS in patients with progressive RAIR DTC treated with sorafenib. Thus, LMR could be a simple prognostic biomarker in patients with progressive RAIR DTC.