GATA-3 expression is not associated with complete pathological response in triple negative breast cancer patients treated with neoadjuvant chemotherapy

Objective: The prognosis for patients with triple negative breast cancer (TNBC) is poor, however, a subset will demonstrate complete pathological response (pCR) to chemotherapy. GATA-3 and AR may be a negative predictors for pCR although it is unclear if these results apply to TNBC. Methods: Patients diagnosed with TNBC and treated with neoadjuvant chemotherapy were identified. Immunohistochemistry was performed for GATA-3 and AR. Both were scored using a composite of staining intensity and percentage cells stained. The primary outcome was pCR. Results: Twenty-four patients were included and 7 achieved pCR. There was no difference in the pre-chemotherapy tumor size (44 +/- 28 mm vs. 54 30 mm; p = 0.764) or lymph node status (86% vs. 71%; p = 0.629) between patients with and without pCR. GATA-3 expression was present in 20 cases (83%)while AR was present in 6 cases (25%). No AR expression was seen in 15 cases (63%) with GATA-3 positivity. There was no difference in either GATA-3 (4.3 +/- 2.7 vs. 3.6 +/- 2.5; p = 0.549) or AR (1.4 +/- 2.5 vs. 1.1 +/- 2.4; p = 0.778) expression between patients with and without pCR. Conclusions: GATA-3 expression is frequent in TNBC even in the absence of AR. However, neither GATA-3 nor AR are associated with pCR after neoadjuvant chemotherapy. (C) 2016 Elsevier GmbH. All rights reserved.