Expression of ER, PgR, HER1, HER2, and response: a study of preoperative chemotherapy

Purpose: To identify the role of estrogen (ER), progesterone (PgR), epidermal growth factor 1 (HER1), and HER2 receptors in predicting response to preoperative chemotherapy. Materials and methods: We reviewed the pretreatment biopsies of 485 patients with locally advanced breast cancer (cT2-T4, N0-2, M0) treated with preoperative chemotherapy. The incidence of pathological complete remission (pCR) and outcome were assessed with respect to clinical and pathological findings including ER/PgR status (absent versus expressed), HER1 (absent versus expressed) and HER2 (overexpressed versus none) expression. Results: Patients with ER/PgR-absent tumors were 12.0 times [95% confidence interval (CI) 4.93-29.28] more likely to achieve a pCR (P < 0.0001). Predictors of disease-free survival (DFS) at the univariate analysis included HER1 [hazards ratio (HR) 1.6, 95% CI 1.04-2.32, P = 0.03] and HER2 (HR 1.6, 95% CI 1.08-2.38, P = 0.02) expression. A statistically significant difference in DFS was confirmed at the multivariate analysis for patients with ER/PgR-absent disease (HR 2.1, 95% CI 1.41-2.99, P = 0.0002). Conclusions: The pCR rate is higher and outcome worse for patients with ER/PgR-absent tumors. HER1 and HER2 expression may have a prognostic role in locally advanced breast cancer and warrant further studies.