Topical or Oral Minoxidil for the Treatment of Endocrine Therapy-Induced Alopecia in Patients With Stage I-IV Breast Cancer

Inclusion Criteria: * Women \>= 18 years of age * Established diagnosis of breast cancer stages I-IV * On endocrine therapy including tamoxifen or aromatase inhibitors with or without concurrent use of ovarian function suppression * Self-reporting hair loss since starting endocrine therapy Exclusion Criteria: * Pregnant or nursing women * Current chemotherapy use or prior chemotherapy use within the last 2 years * History of scarring/cicatricial alopecia or alopecia areata * Prior use of oral or topical minoxidil * Prior or ongoing use of spironolactone * Known sensitivity to minoxidil * Untreated hypothyroidism or iron deficiency as determined by thyroid stimulating hormone (TSH) with reflex free T4 and ferritin level \> 40 to be checked at the time of enrolling if not completed in the 12 months prior