No run-in period is planned. The intervention phase will begin within 5 days following randomization and end on the day prior to surgical resection. The 4-OHT group will apply active gel 2 mg daily to each breast for 4-10 weeks and take oral placebo. The TAM group will take 20 mg TAM orally daily and apply gel placebo. The last dose of study medication will be used on the morning of the day prior to surgery.