A Study of Oral Minoxidil to Treat Hair Loss in Children, Teens, and Young Adults Who Are Cancer Survivors

Inclusion Criteria: * Patients must have been diagnosed with cancer before the age of 17. * They must have completed either systemic or radiation therapy (cytotoxic chemotherapy and external beam radiation therapy) for their cancer at least 1 year prior to study entry. * They must be between 6-18 years old at the time of enrollment. * They must have a clinical diagnosis of persistent or late alopecia for \>6 months and that is definitely, probably, or possibly related to prior chemotherapy and/or radiation. Exclusion Criteria: * Had a history of alopecia prior to systemic or radiation therapy for cancer, or has alopecia unrelated to cancer treatment. * Have scalp disorders that preclude the evaluation of alopecia, such as psoriasis * Has a known hypersensitivity to minoxidil * Concurrent use of other therapies for alopecia * Concurrent active anticancer therapies (cytotoxic, targeted, endocrine, immunologic) * History of chronic sclerotic cutaneous GvHD affecting the scalp * Active chronic cutaneous GvHD * History of orthostatic or symptomatic hypotension, syncope related to hypotension; systolic less than or equal than 100 (for adults) and 90 (for children) at screening. * Pregnancy. * Cardiovascular disease that in the opinion of the cardiologist makes the patient unsuitable for therapy * Blood pressure less than the 5th percentile or less than 90/50 mmHg for children 10 years or older