Prognostic role of disease extent and lymphocyte-monocyte ratio in advanced melanoma

Advanced melanoma (AM) represents the leading cause of death from skin cancer. To date, the crucial role of the immune system in AM pathogenesis and progression is well known, but the prognostic value of clinicopathological characteristics remains unclear. Lactate dehydrogenase (LDH) is an ascertained prognostic indicator and previous data showed that AM patients treated with BRAF and MEK inhibitors with normal LDH values and fewer than three metastatic sites achieved a better outcome. Moreover, the neutrophil-to-lymphocytes ratio and the lymphocyte-to-monocyte ratio (LMR) have been suggested as other potential prognostic factors. The aim of this study was to evaluate the prognostic value of LMR together with other clinical biomarkers in patients with AM. We retrospectively analyzed 162 consecutive patients with AM treated between January 2010 and March 2016. Outcome was measured in terms of overall survival (OS). In our cohort, the BRAF mutation was present in 74 (46%) patients. Overall, 42 and 26% of the patients received targeted therapy and immunotherapy, respectively. After 48 months of follow-up, 129 (78%) patients died; the median OS was 12.8 months. High LMR was associated with the following clinicopathological characteristics: absence of central nervous system localization (P=0.011), fewer than three metastatic sites (P=0.014), and normal LDH (P=0.006). In multivariate analysis, Eastern Cooperative Oncology Group Performance Status>1 [hazard ratio (HR) 7.87, P=0.001], high LDH (HR 2.76, P=0.006), and high LMR (HR 0.76, P=0.033) were associated significantly with OS. In conclusion, LMR seems to be associated with OS. Further prospective investigations are needed to confirm these data and introduce peripheral blood cell count in daily clinical use.