Vitiligo-like lesions in patients with advanced breast cancer treated with cycline-dependent kinases 4 and 6 inhibitors

Purpose Introduction of cyclin-dependent inhibitors was a milestone in therapeutics for patients with estrogen receptor+/HER2- metastatic breast cancer. Despite the wide use of such agents and remarkable improvement of survival rates, drug-related adverse events are not yet fully characterized. We describe vitiligo-like lesions as a new adverse event occurring in patients with advanced breast cancer treated with cyclin-dependent inhibitors. Methods We performed an international retrospective study including patients with advanced breast cancer who developed vitiligo-like lesions during treatment with cyclin-dependent kinases 4 and 6 inhibitors, in the period January 2018-December 2019. Patients > 18 years, both males and females, were recruited at six Dermatology Departments located in Italy (3), France (1) and Greece (2). We evaluated epidemiological and clinical characteristics, impact on quality of life and outcome of vitiligo-like lesions in patients treated with cyclin-dependent 4 and 6 inhibitors. The percentage of skin involved by vitiligo-like lesions was assessed using the Body Surface Area (BSA) score. Changes in patients' quality of life were investigated through the evaluation of the Dermatology Life Quality Index (DLQI) questionnaire. Results Sixteen women (median age: 62.5 years; range 40-79 years) treated with cyclin-dependent kinases 4 and 6 inhibitors for advanced breast cancer presented with vitiligo-like lesions during follow-up visits. Cutaneous lesions consisted of white, irregular macules and patches located mainly on sun-exposed areas in 11/16 patients or diffuse to the entire body surface in 5/16. Cutaneous lesions clearly impaired the quality of life of patients tested (DLQI >= 10). Conclusions We present for the first time, to our knowledge, a case series of vitiligo-like lesions developing in patients with advanced breast cancer treated with cyclin-dependent kinases 4 and 6 inhibitors. We showed that such lesions further impair the patients' quality of life and their treatment is challenging.