Clinical characteristics of patients with cutaneous melanoma according to variants in the melanocortin 1 receptor gene

Introduction: Patients with cutaneous melanoma who are carriers of polymorphisms in the melanocortin 1 receptor gene (MC1R) have distinctive clinical characteristics. The objective of this study was to determine the clinical characteristics associated with differing degrees of functional impairment of the melanocortin 1 receptor, as determined by the number and type (R and r) of MC1R polymorphisms.

Material and methods: In total, 1044 consecutive patients with melanoma diagnosed in our hospital after January 2000 were selected from the melanoma database. These patients were divided into 3 groups according to a score based on nonsynonymous MC1R polymorphisms. The frequencies of epidemiologic, phenotypic, and histologic variables and personal and family history of cancer were compared.

Results: Patients with a score of 3 or more were more likely to develop melanoma before the age of 50 years (odds ratio [OR]=1.47), have a tumor on the head or neck (OR=3.04), have a history of basal cell carcinoma or cutaneous squamous cell carcinoma (OR=1.70), have atypical nevi (OR=1.74), and have nevi associated with the melanoma (OR=1.87).

Conclusions: The use of a scoring system for MC1R polymorphisms allowed us to identify associations between the degree of functional impairment of the melanogenesis pathway and the clinical characteristics of the patients and melanoma presentation.