HER2 and response to anthracycline-based neoadjuvant chemotherapy in breast cancer

Abstract

Background: The predictive role of human epidermal growth factor receptor 2 (HER2) to adjuvant anthracyclinebased chemotherapy remains controversial. Here, we investigated the association between HER2 status and pathological response in breast cancer patients who received neoadjuvant anthracycline-based regimens. Patients and methods: Women (n = 538) with operable primary breast cancer received neoadjuvant anthracyclinebased chemotherapy. Pathological complete response (pCR) was defined as no invasive breast tumor cells in breast after completion of neoadjuvant chemotherapy. HER2 status was determined by immunohistochemistry and/or by fluorescence in situ hybridization in core biopsy breast cancer tissue obtained before initiation of neoadjuvant chemotherapy. Results: In this cohort of 538 patients, 23.9% of patients achieved a pCR in their breast. HER2-positive tumors had a lower rate of pCR than did HER2-negative tumors (14.7% versus 25.7%, P = 0.013); negative HER2 status remained as an independent favorable predictor of pCR after adjusted for age, estrogen receptor, progesterone receptor, tumor size, chemotherapy cycles, and tumor grade in a multivariate analysis (odds ratio = 3.14; 95% confidence interval = 1.60-6.16, P = 0.001). Furthermore, patients with a pCR had a higher 3-year disease-free survival (DFS) rate than did patients without a pCR (P = 0.007). Conclusion: Women with HER2-negative breast cancers rather than HER2-positive tumors benefit from anthracycline-based neoadjuvant chemotherapy. © The Author 2010. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.