If you have been diagnosed with early-stage hormone receptor-positive breast cancer, Anastrozole testosterone replacement mechanism of action you will likely be recommended to take anastrozole for at least five years after surgery to reduce the risk of recurrence. After five years, if breast cancer has been detected in the lymph nodes, the woman may be recommended to take anastrozole or another aromatase inhibitor for an additional five years, for a total of 10 years of hormone therapy.