Vitiligo is an independent favourable prognostic factor in stage III and IV metastatic melanoma patients: Results from a single-institution hospital-based observational cohort study

Background: The clinical features and the prognostic relevance of vitiligo lesions in melanoma patients are still controversial. This prospective observational study was designed to characterise the clinical features of melanomaassociated vitiligo, to analyse the association with other autoimmune manifestations and to ascertain whether the development of vitiligo lesions carries a prognostic relevance on the clinical course of melanoma. Materials and methods: A total of 2954 consecutive patients have been included; multivariate analyses of distant metastasis-free survival (DMFS) and overall survival (OS) were carried out to ascertain the independent prognostic role of vitiligo as a time-dependent covariate. Results: Vitiligo was demonstrated in 83 of 2954 melanoma patients (2.8%). A significantly higher percentage of autoimmune diseases was demonstrated in vitiligo patients (7 of 83) with respect to patients without vitiligo (80 of 2871) (P = 0.004). Multivariate analyses selected the time-dependent covariate vitiligo as the favourable independent prognostic variable associated to a longer DMFS in stage III and a higher OS in both stage III and stage IV. Conclusion: Melanoma-associated vitiligo should be considered as a distinct clinical entity, separate from vitiligo vulgaris, and identifies a subgroup of patients characterised by a high prevalence of immune-mediated diseases and by a favourable prognosis.