Neoadjuvant chemotherapy versus neoadjuvant hormonal therapy in postmenopausal women with ER-positive, HER2/neu negative locally advanced breast cancer.

Abstract

595 Background: Postmenopausal women with large ER+/HER-2 negative tumors frequently receive neoadjuvant chemotherapy (NC), but pathological complete response (pCR) rates are low. Neoadjuvant hormonal therapy (NH) may offer benefit in this setting. Methods: Retrospective review of medical records from University of Miami/Jackson Memorial Hospital from 1998-2011. Primary outcomes: pCR (absence of invasive tumor in breast and lymph nodes at surgery), recurrence free survival (RFS) and tumor size reduction evaluated through comparison of palpable breast mass size at presentation with pathological tumor size in surgical specimen, and categorized as good response (GR) ≥ 30% reduction or no response (NR) < 30%. The Kaplan-Meier method and the log-rank test were used in the analysis of RFS. Results: Data from 151 post-menopausal women with ER+/HER-2 negative BC who received NC (57%) or NH (43%) was analyzed. Median follow-up among alive patients with no evidence of disease was 5.4 years in NC and 2.9 years in NH. Mean age was higher in the NH group (63.3 vs 56.1, p<0.0001). There were no racial or ethnic differences between the groups. Clinical stage was comparable in NC and NH (IIA 5.8% vs 9.2%, IIB 25.6% vs 20%, IIIA 37.2% vs 29.2%, IIIB/IIIC 31.4% vs 41.5%, p=0.775). Tumor histology was predominantly ductal in both groups (NC 85.7% and NH 78.5%, p=0.247). pCR was similar in NC and NH (4.7% vs 0%, p=0.078) along with RFS (median 8.5 yrs vs 6.0 yrs, p=0.946). In the NC group, GR was significantly more frequent (77.9% vs 60%, p=0.017). Among patients in the NH group, having GR was predictive of longer RFS (5-year rate 83.7% vs 50.5%, p=0.014). Breast only pCR occurred at equivalent rates between NC and NH (9.3% vs 3.1%, p=0.189) as did the absence of lymph node metastasis (29.1% vs 26.2%, p=0.606). In the NH cohort 38.5% received no adjuvant chemotherapy. Conclusions: NH provides an effective alternative to NC and, if there is a GR, may preclude the need for chemotherapy in over one third of postmenopausal women with large ER positive/HER-2 negative breast cancer.