A 52-year-old postmenopausal woman with ER-positive, HER2-negative early breast cancer (T1N0M0) is started on adjuvant endocrine therapy. Which aromatase inhibitor is NOT appropriate for a premenopausal woman, and why?
- A Letrozole, because it causes ovarian suppression
- B Exemestane, because it is steroidal
- C Anastrozole, because it cannot overcome ovarian estrogen production ✓
- D Tamoxifen, because it is not an aromatase inhibitor
Correct answer: C. Anastrozole, because it cannot overcome ovarian estrogen production
Explanation
Aromatase inhibitors (letrozole, anastrozole, exemestane) are contraindicated in premenopausal women because the ovary can compensate by increasing aromatase production. They are only effective in postmenopausal women where peripheral aromatization is the main estrogen source. In premenopausal women, tamoxifen or ovarian suppression plus AI is used.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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