Objective: The aim of this study was to look for predictive and prognostic factors in anthracycline-based neoadjuvant chemotherapy.
Methods: Three hundred and nine patients with early-stage or locally advanced breast cancer were enrolled in this study and preoperatively treated with neoadjuvant chemotherapies in intense dose-dense (cyclophosphamide + epirubicin) or conventional (paclitaxel + epirubicin) regimens. Outcome parameters included overall objective response rate, as well as factors for determining pathological features influencing the efficacy of chemotherapy, such as estrogen receptor, progesterone receptor, and HER2 status, Eastern Cooperative Oncology Group (ECOG) score, tumor size, tumor inflammation, and lymph node metastasis.
Results: The overall pathological complete response (pCR) rate was 14.3%, and the main factor affecting the efficacy of chemotherapy was HER2 expression. The pCR rate was significantly higher for patients with HER2 overexpression, compared with patients with low HER2 expression (27.5% vs. 9.6%, p<0.001). The recurrence risk for patients with pCR decreased 1.12-fold compared with patients without pCR (5-year disease-free survival [DFS]: 81.8% vs. 65.7%, p=0.038). Patients in the HER2 overexpression subgroup benefited more from pCR than those in the HER2 low expression group (5-year DFS: 86.4% vs. 62.1%, p=0.049).
Conclusion: HER2 overexpression in primary tumors might be a predictive marker for good efficacy of anthracycline-based neoadjuvant chemotherapy. The pCR is a suitable prognostic factor, even for patients with HER2 overexpression.