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

ObjectiveThe 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.MethodsPatients 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.ResultsTwenty-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.ConclusionsGATA-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.