Chemotherapy-induced amenorrhea: influence on disease-free survival and overall survival in receptor-positive premenopausal early breast cancer patients.

BACKGROUND: The aim of this study was to evaluate the influence of early chemotherapy-induced amenorrhea (CIA) on disease-free survival and overall survival in premenopausal patients with receptor-positive early breast cancer treated with adjuvant chemotherapy without any hormonotherapy. PATIENTS AND METHODS: Retrospectively, we reviewed data from 130 premenopausal patients with localized hormone-sensitive breast cancer. These patients were treated between 1985 and 1995 at the same institution. They all underwent a loco-regional treatment and adjuvant chemotherapy. Early CIA was defined as an amenorrhea arising during the first year following the beginning of chemotherapy. Predictors of early CIA were examined. The survival analyses were done using the Kaplan-Meier method and Cox analysis.
RESULTS: Median follow-up was 9 years. Mean age was 42.9 +/- 5 years. Ninety-two per cent of patients had histologically-proven positive axillary nodes. Adjuvant chemotherapy contained no anthracycline in 63%. Early CIA occurred during or after adjuvant chemotherapy in 57% of the patients. It was definitive in 91%. In our study, age was the only CIA predictor in univariate analysis. Women who experienced early CIA tend to have a longer disease-free survival, but the difference was not significant. This trend was lost in multivariate analysis, most probably due to the small sample size. The overall survival was not different.
CONCLUSION: Although not statistically significant, our results on a very selected population of patients suggest that a chemotherapy-induced amenorrhea might have its own therapeutic effect besides the cytotoxic action of chemotherapy.