Topical minoxidil is widely used to treat hair loss, but new findings suggest that a combination of oral and topical minoxidil could be effective for women with breast cancer who have experienced alopecia from anticancer treatment.
In a retrospective cohort study of women with breast cancer and anticancer therapy–induced alopecia, researchers found that combining low-dose oral minoxidil (LDOM) and topical minoxidil achieved better results than topical minoxidil alone and that the treatment was well tolerated. A total of 5 of the 37 patients (13.5%) in the combination therapy group achieved a complete response, defined as an improvement of alopecia severity from grade 2 to grade 1, compared with none of the 19 patients in the topical therapy–only group.
In contrast, none of the patients in the combination group experienced worsening of alopecia, compared with two (10.5%) in the topical monotherapy group.
The study was published online in the Journal of the American Academy of Dermatology.
Topical minoxidil is approved by the US Food and Drug Administration to treat androgenetic alopecia. Oral minoxidil is not approved for treating hair loss but has been receiving increased attention as an adjunctive therapy for hair loss, particularly for women. Oral minoxidil is approved for treating hypertension but at much higher doses.
An increasing number of studies have been conducted on the use of oral minoxidil for the treatment of female pattern hair loss, dating back to a pilot study in 2017, with promising results. The findings suggest that LDOM might be more effective than topical therapy, well tolerated, and more convenient for individuals to take.
Asked to comment on the results of the new study, Kai Johnson, MD, a medical oncologist who specializes in treating patients with breast cancer at the Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, noted that the study, like most small-scale retrospective studies, is hypothesis-generating. However, he added, "I'd be hesitant to broadly recommend this practice of dual therapy ― oral and topical minoxidil together ― until we see a placebo-controlled prospective study performed demonstrating clinically meaningful benefits for patients."
Another factor is the study endpoints. "While there was a statistically significant benefit documented with dual therapy in this study, it's important to have study endpoints that are more patient oriented," Johnson said. The most important endpoint for patients would be improvements "in the actual alopecia grade, which did occur in 5 of the 37 of dual-therapy patients, vs 0 topical minoxidil patients."
George Cotsarelis, MD, chair of the Department of Dermatology and professor of dermatology at the University of Pennsylvania, Philadelphia, also weighed in. He questioned whether adding the topical therapy to oral minoxidil actually improved the results. "What was missing was a study arm that used the oral alone," he said in an interview. "So we don't know how effective the oral therapy would be by itself and if combining it with the topical is really adding anything."
He noted that oral minoxidil as a treatment for hair loss is gaining traction, and it's clear that it is effective. However, the risk of side effects is higher. "The risk isn't that high with the low dose, but it can grow hair on places other than the scalp, and that can be disconcerting," Cotsarelis said. In this study, two women who took the oral drug reported edema, and one reported headache and dizziness, he noted. Hypertrichosis was reported by five patients who received the combination.
In the study, Jeewoo Kang, MD, and colleagues from the Seoul National University College of Medicine evaluated the efficacy of LDOM in 100 patients with breast cancer who had been diagnosed with persistent chemotherapy-induced alopecia (pCIA) and endocrine therapy–induced alopecia (EIA) at a dermatology clinic.
They conducted a retrospective review of medical records, standardized clinical photographs, and trichoscopic images to evaluate the alopecia pattern, severity, treatment response, and posttreatment changes in vertex hair density and thickness.
Compared with those with EIA alone, patients with pCIA were significantly more likely to have diffuse alopecia (P < .001), and they were more likely to have more severe alopecia, although this difference was not significant (P = .058). Outcomes were evaluated for 56 patients who were treated with minoxidil (19 with topical minoxidil alone and 37 with both LDOM and topical minoxidil) and for whom clinical and trichoscopic photos were available at baseline and at the last follow-up (all patients were scheduled for follow-up at 3-month intervals).
The results showed that those treated with 1.25–5.0 mg/d of oral minoxidil and 5% topical minoxidil solution once a day had better responses (P = .002) and a higher percentage increase in hair density from baseline (P = .003) compared with those who received topical minoxidil monotherapy.
However, changes in hair thickness after treatment were not significantly different between the two groups (P = .540).
In addition to the five (13.5%) cases of hypertrichosis, two cases of edema (5.4%), and one case of headache/dizziness (2.7%) among those who received the combination, there was also one report of palpitations (2.7%). Palpitations were reported in one patient (5%) who received topical monotherapy, the only adverse event reported in this group.
Johnson noted that at his institution, a dermatologist is conducting a clinical trial with oncology patients post chemotherapy and endocrine therapy. "She is looking at a similar question, although she is comparing oral minoxidil to topical minoxidil directly rather than in combination," he said. He noted that there is also an active clinical trial at Northwestern University, Chicago, of LDOM alone for patients with chemotherapy-induced alopecia.
"So there is a lot of momentum surrounding this concept, and I feel we will continue to see it come up as a possible treatment option, but more data are needed at this time before it can become standard of care," Johnson added.
No funding for the study was reported. The authors have disclosed no relevant financial relationships.
J Am Acad Dermatol. Published online December 13, 2022. Abstract
Roxanne Nelson is a registered nurse and an award-winning medical writer who has written for many major news outlets and is a regular contributor to Medscape.
Lead image: Nadzeya Kolabava/Dreamstime
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Cite this: Oral Minoxidil Improves Anticancer Treatment–Induced Alopecia in Patients With Breast Cancer - Medscape - Dec 22, 2022.