Resumption or persistence of menstruation after cytotoxic chemotherapy is a prognostic factor for poor disease-free survival in premenopausal patients with early breast cancer

Abstract

We investigated the relationship between resumption or persistence of menstruation after cytotoxic chemotherapy (RM) and disease-free survival (DFS) in premenopausal patients with early breast cancer. Medical records from 872 patients who received cytotoxic chemotherapy for stage I to III breast cancer were retrospectively reviewed. The median patient age was 41 years (range, 21-54) and the median follow-up duration was 6.2 years (range, 0.7-10.4). Six hundred ninety-two patients (79.4%) were hormone receptor (HR) positive and the majority of these received tamoxifen therapy after completing chemotherapy. The chemotherapy-induced amenorrhea (CIA) rate was 76.7% (n = 669), and 51.8% (n = 452) experienced RM during the follow-up period. One hundred twenty-one (13.9%) patients had persistent menstruation without CIA. DFS was significantly affected by younger age at diagnosis (≤35 years) (P = 0.013), tumor size > 2 cm (P < 0.001), node positivity (P < 0.001), HR negativity (P < 0.001), HER2 positivity (P = 0.010), and RM (P < 0.001). HR negativity [hazard ratio 1.7, 95% confidence interval (CI) 1.2-2.4, P = 0.006], tumor size > 2 cm (hazard ratio 2.1, 95% CI 1.4-3.0, P < 0.001), node positivity (hazard ratio 3.0, 95% CI 2.0-4.7, P < 0.001), and RM (hazard ratio 1.8, 95% CI 1.2-2.7, P = 0.004) remained significant factors for DFS on multivariate analysis. A considerable proportion of premenopausal patients treated with chemotherapy experienced RM after CIA. RM was a poor prognostic factor for DFS in premenopausal patients with early breast cancer.