Inadvertent use of aromatase inhibitors in patients with breast cancer with residual ovarian function: cases and lessons.

Aromatase inhibitors (AIs) are important adjunctive therapy for postmenopausal women with hormone receptor-positive, early-stage breast cancer. At the present time, AIs have no role for the management of breast cancer in premenopausal women. We report on several cases of the inadvertent use of AI therapy among women with residual ovarian function.