Immune checkpoint inhibitor-induced vitiligo in cancer patients: characterization and management.

This study highlights the range of non-melanoma cancers where ICI-induced vitiligo can be present and challenges the exclusivity of this phenomenon to melanoma. We believe our manuscript will encourage awareness in our colleagues and stimulate interest in further studies to elucidate the mechanisms of ICI-induced vitiligo in both melanoma and non-melanoma cancers, and to understand whether this phenomenon holds the same positive prognostic value in both cancer groups. This is a retrospective cohort study from a single-institution's electronic medical record for cancer patients treated with ICIs who subsequently developed vitiligo. We identified 151 patients with ICI-induced vitiligo, 19 (12.6%) non-melanoma and 132 (77.4%) melanoma patients. Time to onset of vitiligo was nearly doubled in the non-melanoma cohort, however, this is confounded by possible delayed diagnosis or under reporting of this asymptomatic condition in patients who do not regularly receive skin exams. The majority of patients had a stable course of vitiligo with 91.4% receiving no treatment in this largely Caucasian cohort. Two patients with non-melanoma cancers and Fitzpatrick type IV or above skin received treatment with narrowband ultraviolet B light therapy and topical steroids with near-complete response. This study highlights the occurrence of ICI-induced vitiligo in a variety of non-melanoma cancers, where skin of color patients will be more prevalent and the need for treatment will potentially be more urgent. Further study is needed to elucidate the mechanism of ICI-induced vitiligo and determine if non-melanoma cancers have the same association between vitiligo and increased tumor response.