A prospective longitudinal analysis of the predictors of amenorrhea after breast cancer chemotherapy: Impact of BRCA pathogenic variants

BACKGROUND: Better tools for post‐chemotherapy amenorrhea risk assessment are needed for fertility preservation decision‐making. Our aim was to determine the predictors of amenorrhea risk at 12 and 18 months post‐chemotherapy in women with breast cancer. METHODS: 142 women with breast cancer were longitudinally followed for their menstrual changes at 6, 12, and 18 months after the completion of adjuvant chemotherapy with an Anthracycline‐Cyclophosphamide‐based (AC‐based) or Cyclophosphamide‐Methotrexate +5‐Fluorouracil regimen. Pre‐ and/or post‐chemo AMH levels, age, BMI, tamoxifen use, regimen type, and germline BRCA pathogenic variant (gBRCApv) status were evaluated for the prediction of amenorrhea at 6–18 months. RESULTS: In multivariable‐adjusted logistic regression, age (p = 0.03) and AMH (p = 0.03) at 12 months, and gBRCApv status (p = 0.03) at 18 months were significant predictors of amenorrhea (areas under the ROC curve of 0.77 and 0.76, for 12 and 18 months, respectively) among 102 evaluable subjects. An undetectable AMH immediately post‐chemotherapy was predictive of amenorrhea with <18 month follow‐up. In longitudinal analysis estimating time trends, baseline AMH and gBRCApv status was associated with the risk of amenorrhea over 6–18 months; the AMH >2.0 ng/mL group showed attenuated time‐trend risk of amenorrhea versus AMH ≤2.0 group (ratio of ORs = 0.91, 95% CI = 0.86–0.97, p = 0.002), while the gBRCApv + showed a steeper time trend, versus the controls (ratio of ORs = 1.12, 95% CI = 1.04–1.20, p = 0.003). CONCLUSIONS: In addition to the pre‐ and post‐treatment AMH levels, gBRCApv status is a novel potential predictor of amenorrhea at 12 and 18 months after chemotherapy. The higher likelihood of amenorrhea in women gBRCApv suggests that they are more prone to losing their fertility post‐chemotherapy.