Oral minoxidil for late alopecia in cancer survivors.

Purpose: Late alopecia, defined as incomplete hair regrowth > 6 months following cytotoxic chemotherapy or > 6 months from initiation of endocrine therapy, negatively impacts quality of life and may affect dose intensity of adjuvant therapy. This study investigates the effect of oral minoxidil in women with chemotherapy and/or endocrine therapy-induced late alopecia.

Methods: The rate of clinical response was assessed by standardized photography and quantitated with trichoscopy.

Results: Two hundred and sixteen patients (mean age 57.8 ± 13.7) were included. The most common cancer diagnosis was breast, in 170 patients (79.1%). Alopecia developed after chemotherapy in 31 (14.4%) patients, endocrine monotherapy in 65 (30.1%) patients, and chemotherapy followed by endocrine therapy in 120 (55.6%) patients. In 119 patients, standardized photography assessments were used to determine clinical change in alopecia after a median of 105 (IQR = 70) days on oral minoxidil and revealed improvement in 88 (74%) patients. Forty-two patients received quantitative trichoscopic assessments at baseline and at follow-up after a median of 91 (IQR = 126) days on oral minoxidil. Patients had clinically and statistically significant increases in frontal hair shaft density (from 124.2 hairs/cm² at initial to 153.2 hairs/cm² at follow-up assessment, p = 0.008) and occipital shaft density (from 100.3 hairs/cm² at initial to 123.5 hairs/cm² at follow-up assessment. p = 0.004). No patients discontinued oral minoxidil due to adverse events.

Conclusions: Overall, oral minoxidil was well tolerated by patients and may benefit both frontal and occipital late alopecia in cancer survivors treated with cytotoxic and/or endocrine therapy by increasing hair shaft and follicle density.