Markedly reduced incidence of melanoma and nonmelanoma skin cancer in a nonconcurrent cohort of 10,040 patients with vitiligo

Background: Genetic findings suggesting a lower susceptibility to melanoma in patients with vitiligo are supported by recent clinical studies. Nonmelanoma skin cancer (NMSC) has also been studied, but mainly in small samples, and with conflicting results. Objective: We sought to study the relative risk (RR) of melanoma and NMSC in patients with vitiligo compared with that in patients seen for vascular surgery. Methods: The frequency of melanoma and NMSC was compared between patients with vitiligo and patients seen for vascular surgery. Occurrence of skin cancer was compared by computing RR and modeled using multiple logistic regression. Results: Overall, the crude RR for melanoma was 0.24 (95% confidence interval [CI] 0.13-0.45) in patients with vitiligo compared with those with a nondermatologic condition (occurrence 1.1 parts per thousand, 95% CI 0.5 parts per thousand-2.0 parts per thousand in patients with vitiligo and occurrence 4.5 parts per thousand, 95% CI 3.8 parts per thousand-5.4 parts per thousand in the control cohort). The crude RR for NMSC was 0.19 (95% CI 0.14-0.17) and the occurrence was 3.8 parts per thousand (95% CI 2.7 parts per thousand-5.2 parts per thousand) among patients with vitiligo and 19.6 parts per thousand (95% CI 18.0 parts per thousand-21.4 parts per thousand) in control subjects. Patients with vitiligo who underwent phototherapy had a markedly higher risk of both cancers. Conclusions: In our large study, patients with vitiligo have a decreased risk of developing skin neoplasms, even considering that a larger proportion in this patient group is exposed to higher levels of ultraviolet radiation.