A Cross-Sectional Study of Platelet-to-Lymphocyte Ratio in Relation to Pigment Cell Nevi and Atypical Mole Syndrome

Melanocytic nevi (MN) and atypical melanocytic nevi (AMN) are established risk factors for cutaneous malignant melanoma (CMM), with patients exhibiting atypical mole syndrome (AMS) facing an even greater risk. Peripheral blood biomarkers-including neutrophil-to-lymphocyte ratio (NLR), eosinophil-to-lymphocyte ratio (ELR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)-have been linked to various cancers, including CMM. This cross-sectional study aimed to investigate the relationship between these biomarkers and MN and AMS, which are common phenotypes among melanoma patients.

A total of 505 subjects (aged 21-79, 254 males and 249 females, 96 with immunosuppression) at elevated risk of any type of skin cancer were examined for MN, AMN, level of cutaneous photodamage, and other potential confounding factors. A peripheral blood sample was analyzed for blood cells.

PLR levels were significantly higher in subjects with more than 50 nevi or AMS. In multivariable logistic regression models, high PLR was significantly associated with having more than 50 melanocytic nevi (OR: 2.015, 95% CI: 1.159-3.501, p = 0.01) and with atypical mole syndrome (OR: 4.092, 95% CI: 2.012-8.323, p < 0.001). Other significant factors associated with high MN density and AMS were lower age, male sex, higher BMI, no immunosuppression, and fewer actinic keratoses. However, NLR, ELR, and SII showed no relation to MN or AMS.

This study demonstrates a statistically significant association between elevated PLR and the presence of more than 50 MN or AMS, whereas no associations were observed with NLR, ELR, or SII. This specific relationship suggests that PLR may have particular relevance in the context of multiple MN and AMS, potentially influencing its interpretation in melanoma prognosis. However, further studies are needed to validate this finding, explore underlying biological mechanisms, and assess causality.