Prognostic Value of the Neutrophil-to-lymphocyte Ratio, Platelet-to-lymphocyte Ratio and Monocyte-to-lymphocyte Ratio in Melanoma Patients: A Cohort Study

The prognostic value of the neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and monocyte-lymphocyte ratio in patients with melanoma has yielded controversial results in the literature. A retrospective single -centre cohort study was conducted from 1998 to 2020, including patients diagnosed with invasive melanoma. A total of 2,721 patients were included in the study. The median follow-up was 8.23 years (IQR 4.41-13.25). The median baseline neutrophillymphocyte ratio, platelet-lymphocyte ratio and monocyte-lymphocyte ratio values increased significantly ( p < 0.001) with the increasing American Joint Committee on Cancer stage. The optimal cut-off values for neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and monocyte-lymphocyte ratio were determined as 2.1, 184 and 0.2, respectively. In the multivariate analysis, high levels of neutrophil-lymphocyte ratio (>= 2.1), platelet-lymphocyte ratio (>= 184) and monocyte-lymphocyte ratio (>= 0.2) were independently associated with significantly shorter melanoma-specific survival (neutrophil-lymphocyte ratio: HR 1.30, 95% CI 1.06-1.60, p = 0.013; platelet-lymphocyte ratio: HR 1.37, 95% CI 1.06-1.76, p = 0.014; monocytelymphocyte ratio: HR 1.29, 95% CI 1.05-1.58, p = 0.015) and overall survival (neutrophil-lymphocyte ratio: HR 1.39, 95% CI 1.19-1.64, p < 0.001; plateletlymphocyte ratio: HR 1.44, 95% CI 1.19-1.74, p < 0.001; monocyte-lymphocyte ratio: HR 1.42, 95% CI 1.21-1.66, p < 0.001). High levels of neutrophillymphocyte ratio and monocyte-lymphocyte ratio were also associated with poor relapse-free survival, while platelet-lymphocyte ratio was not. In conclusion, baseline neutrophil-lymphocyte ratio, plateletlymphocyte ratio and monocyte-lymphocyte ratio were identified as independent predictors for the prognosis of melanoma. SIGNIFICANCE The counts and ratios of peripheral neutrophils, lymphocytes and platelets are readily available and have proven valuable in predicting the prognosis of various malignant tumours. Our study specifically highlights the significance of these markers in primary cutaneous melanoma, where a high baseline neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and monocyte-to-lymphocyte ratio independently correlate with a shorter lifespan. By identifying high -risk patients through these non-invasive measures, clinicians can guide interventions and treatment options, potentially enhancing patient prognosis and overall quality of life.