Efficacy of Neoadjuvant Chemotherapy with Epirubicin and Cyclophosphamide and Weekly Paclitaxel and Trastuzumab in Human Epidermal Growth Factor Receptor 2-Positive Breast Carcinoma: A Real-World Study

Background. Trastuzumab has been introduced a decade ago and demonstrated improvement in the prognosis in patients with human epidermal growth factor receptor 2- (HER2-) positive (+) breast carcinoma (BC). This study is aimed at evaluating the efficacy of epirubicin/cyclophosphamide with weekly paclitaxel-trastuzumab as neoadjuvant chemotherapies in HER2+ BC patients. Methods. A total of 234 HER2+ BC patients were given neoadjuvant chemotherapy (NAC) between 2010 and 2016. The primary endpoints were pathologic complete response (pCR) and disease-free survival (DFS). Univariate and multivariate analyses of clinical and pathological factors associated with pCR and DFS were conducted. Results. The pCR (30.4% vs. 14.8%; P=0.004) and DFS (P=0.036) showed significant differences between patients administered with neoadjuvant trastuzumab therapy and those who did not. Multivariate logistic regression analysis showed that neoadjuvant trastuzumab treatment was regarded as an independent predictor of pCR. Patients with pCR had prolonged DFS (P=0.025). In patients who did not achieve pCR (non-pCR), those who received trastuzumab had more prolonged DFS (P=0.046). The luminal B/HER2+ subtypes had prolonged DFS when compared with nonluminal B/HER2+ subtypes (P=0.010). The luminal B/HER2+ subgroup also showed improved DFS in non-pCR patients (P=0.010). In the subgroup of non-pCR, the luminal B/HER2+ subgroup administered with trastuzumab showed no superior DFS (P=0.168). However, a positive result was observed in patients without trastuzumab (P=0.039). Multivariate analysis showed cT stage (P=0.006) and tumor grade (P=0.041), considering them as significant prognostic factors of DFS. Conclusions. HER2+ BC patients showed improvement in pCR and DFS after neoadjuvant trastuzumab treatment. Patients without pCR had prolonged DFS after trastuzumab maintenance. Although the prognosis of luminal B/HER2+ BC showed favorable outcomes in the non-pCR subgroup, those receiving trastuzumab showed no survival advantage.