CDK4/6 plus aromatase inhibitor-induced alopecia in breast cancer patients.

e12537 Background: Cyclin-dependent kinase (CDK) 4 and 6 inhibitors are a novel therapy for metastatic breast cancer, and have shown to double the risk of alopecia. This study analyzed CDK4/6 plus aromatase inhibitor-induced alopecia (CDKIA), its impact on quality of life (QoL), and response to topical dermatologic therapy. Methods: The study analyzed a retrospective cohort of breast cancer patients diagnosed with CDKIA, evaluating clinical features, QoL, and response to therapy. CDKIA was also compared with endocrine-therapy induced alopecia (EIA). Results: 39 female CDKIA patients (median age 62 years [range 34-81]) were included, and 36 (92%) had standardized clinical images. CDKIA was most commonly attributed to a CDK inhibitor and letrozole in 23 patients (59%). CDKIA was similar to androgenetic alopecia (AGA) in every patient. Compared to EIA, CDKIA took less time to develop, was more severe, was associated with diffuse alopecia more frequently, and consisted of more vellus hairs on trichoscopy (Table). The Hairdex questionnaire, an alopecia-specific QoL survey, showed that CDKIA patients experienced worse QoL than EIA patients ( P < 0.05) and were most affected emotionally ( P < 0.01). There was a moderate to significant alopecia improvement in 11 of 13 CDKIA patients (85%) after treatment with topical minoxidil. Conclusions: CDKIA was clinically similar to AGA in association with diffuse alopecia. Patients with CDKIA had a negative emotional impact on appearance-based QoL. However, topical minoxidil may improve the severity of CDKIA. Baseline characteristics of CDKIA and EIA patients. [Table: see text]