Changes in markers of ovarian reserve and endocrine function in young women with breast cancer undergoing adjuvant chemotherapy

BACKGROUND: Premenopausal women undergoing chemotherapy are at risk for amenorrhea and impaired fertility. The objective of the current study was to assess levels of mullerian inhibitory substance (MIS), estradiol (E2), follicle‐stimulating hormone (FSH), and menstrual status, in women undergoing chemotherapy. METHODS: A nested prospective cohort study was conducted in women aged .05). Serum MIS decreased significantly at 6 weeks and remained suppressed for 52 weeks. E2 levels decreased, and FSH levels increased during chemotherapy; however, at 52 weeks, the levels returned to baseline. At 52 weeks, only 1 patient had MIS above the lower normal range, 15 had return of menstrual function, 11 had premenopausal levels of FSH, and 13 had follicular phase levels of E2. In women aged 35 years, 50% were amenorrheic. Amenorrheic and menstruating women were found to have similar MIS values at baseline and follow‐up. CONCLUSIONS: In young women with BC, chemotherapy decreases MIS rapidly and dramatically. Rapid reductions in MIS do not appear to be predictive of subsequent menstrual function. Ovarian reserve and endocrine function may be affected differently by chemotherapy. Cancer 2010. © 2010 American Cancer Society. In young women with breast cancer, chemotherapy decreases mullerian inhibitory substance (MIS) rapidly and dramatically. Rapid reductions in MIS do not appear to predict subsequent menstrual function. Ovarian reserve and endocrine function may be affected differently by chemotherapy.