LONGITUDINAL OVARIAN RESERVE CHANGES IN WOMEN WITH BREAST CANCER RECEIVING ADJUVANT CHEMOTHERAPY OR TAMOXIFEN-ALONE

ABSTRACT Background To determine the longitudinal impact of adjuvant chemotherapy and tamoxifen-only treatments on ovarian reserve by serum anti-Mullerian hormone (AMH) levels in women with breast cancer. Methods One-hundred-and-forty-two women with a primary diagnosis of breast cancer were prospectively followed with serum AMH assessments before the initiation, and 12, 18 and 24 months after the completion of adjuvant chemotherapy or the start of tamoxifen-only treatment. The chemotherapy regimens were classified into Anthracycline-Cyclophosphamide-based (AC-based) and Cyclophosphamide-Methotrexate+5-Fluorouracil (CMF). Longitudinal data were analyzed by mixed effects model for treatment effects over time, adjusting for baseline age and BMI. Results Both chemotherapy regimens resulted in significant decline in ovarian reserve compared to the tamoxifen-only treatment (p<0.0001 either regimen vs. tamoxifen for overall trend). AMH levels sharply declined at 12 months but did not show a significant recovery from 12 to 18 and 18 to 24 months after the completion of AC-based or CMF regimens. The degree of decline did not differ between the two chemotherapy groups (p=0.53). In contrast, tamoxifen-only treatment did not significantly alter the age-adjusted serum AMH levels over the 24-month follow up. Likewise, the use of adjuvant tamoxifen following AC-based regimens did not affect AMH recovery. Conclusions Both AC-based and CMF regimens significantly compromise ovarian reserve, which does not recover during the 12-24-month post-chemotherapy follow up. In contrast, tamoxifen treatment does not seem to alter ovarian reserve. This novel information should be valuable for fertility preservation counselling and in assessing future reproductive potential of breast cancer survivors.