Serum estradiol above the postmenopausal level after chemotherapy-induced amenorrhea in breast cancer patients

Author(s): Albert S Braverman, Harindar Sawhney, Aron Tendler, Nilesh Patel, Sujatha Rao, Mahmoud El-Tamer, Boriana Kamenova and Jeremy Weedon

Background: Cytotoxic drugs suppress ovarian function and induce permanent or transient amenorrhea in one- to two-thirds of women. Suppression of ovarian function is effective therapy for premenopausal women with hormone receptor-positive breast cancer. Aromatase inhibition is effective for postmenopausal women with hormone receptor-positive breast cancer, but is not indicated in premenopausal women. Objective: We aim to determine whether, and for how long, ovarian estrogen production persists after chemotherapy-induced amenorrhea. Materials & methods: Serum estradiol, follicle-stimulating hormone and luteinizing hormone levels were determined in 56 breast cancer patients, 1–34 months after the onset of chemotherapyinduced amenorrhea. In 18 patients, these values were determined more than once. Postmenopausal estradiol levels are less than 10 pg/ml, follicle-stimulating hormone and luteinizing hormone greater than 20 mIU/ml. Results: The estradiol level was greater than 9 pg/ml at least once in 42 out of 56 patients. For 75 determinations, the estradiol level ranged from less than 10 to 344 pg/ml, with a median of 25 pg/ml and a mean of 41 pg/ml. Estradiol levels were not significantly correlated with either the number of months after the onset of amenorrhea at which they were drawn, or follicle-stimulating and luteinizing hormone levels. Conclusions: Ovarian estradiol production often persists for 1 year or more after chemotherapy-induced amenorrhea.