A 57-year-old woman arrives at the office complaining of left breast pain, fatigue, nausea, and unexplained weight loss. Mammography is ordered for her, and it reveals a 3-cm dominant mass in her left breast. Adenocarcinoma is confirmed by biopsy, and subsequent studies reveal that the tumor is estrogen receptor-positive and human epidermal growth factor receptor 2- (HER2) negative. The patient went through menopause at the age of 52, and her medical history is otherwise unremarkable. Anastrozole treatment is started, which results in a significant reduction in the size of the primary tumor. Which of the following is the best explanation for the therapeutic effect of this agent?

Question

Quizplus · Accepted Answer

Eductional Objective: Estrogen is the main hormone responsible for the growth and development of estrogen receptor (ER)-positive breast tumors.  Aromatase inhibitors (eg, anastrozole, letrozole, exemestane) decrease the synthesis of estrogen from androgens, suppressing estrogen levels and slowing progression of ER-positive tumors.

A 57-Year-Old Woman Arrives at the Office Complaining of Left