Locoregional and Overall Recurrence after Neaodjuvant Endocrine Therapy Versus Chemotherapy in Postmenopausal Women with Estrogen Receptor+ HER2- Breast Cancer

Purpose: We report clinical outcomes in patients treated with neoadjuvant endocrine therapy (NET) versus neoadjuvant cytotoxic chemotherapy (NCT) in a cohort of postmenopausal women with ER+, HER2- breast cancer. Materials and Methods: We retrospectively reviewed 140 patients treated between May 1998 and September 2010 and collected patient, disease, and treatment characteristics, response to neoadjuvant therapy, and clinical outcome. Results: The median age was 59.5 years. Stage group: stage I 2.2%, stage II 26.8%, stage III 71%, the median tumor size 6 cm (range, 1.5 to 19 cm). Fifty-seven (40.7%) received NET and 83 (59.3%) NCT. One patient (1.8%) in the NET group and 7 (8.4%) in the NCT group had a pathologic complete response (P=0.142). The median follow-up was 48.1 months. Five-year cumulative incidence of locoregional recurrence (LRR) among the entire cohort was 4.1% (95% confidence interval [CI]: 1.5, 8.9), and any recurrence 25.3% (95% CI: 17.6, 33.6). There was no difference in cumulative incidence of LRR or overall recurrence between NET and NCT. On multivariate analysis adjusting for receipt of chemotherapy, presenting stage, and positive lymph nodes, the use of adjuvant radiation therapy was associated with decreased risk of LRR (hazard ratio [HR]=0.24, P=0.035), and ypN2 status with higher risk of LRR (HR=4.91, P=0.032). When the same multivariate model was fitted for any recurrence outcome, only ypN2 status was a significant predictor of overall recurrence (HR=3.02, P=0.005). Conclusions: We have demonstrated equivalent locoregional and overall outcomes in patients receiving NET versus NCT in a cohort of postmenopausal women with locally advanced ER+HER2-tumors.