Real-world study of trastuzumab and pertuzumab combined with chemotherapy in neoadjuvant treatment for patients with HER2-positive breast cancer

Clinical trials have shown that trastuzumab (H) and pertuzumab (P) combined with chemotherapy as neoadjuvant therapy increased pathological complete response (pCR) rate of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, date in China in the real world are currently limited. Clinical data from patients with HER2-positive breast cancer who received HP combined with chemotherapy as neoadjuvant therapy at 2 institutions from March 2019 to February 2022 were retrospectively analyzed. Adverse reactions were evaluated using CTCAE version 5.0. The primary endpoint was total pathologic complete response (tpCR; ypT0/isypN0), and the secondary endpoints were breast pathologic complete response (bpCR; ypT0/is) and axillary pathologic complete response (apCR; ypN0). Factors influencing tpCR were also analyzed. A total of 302 patients were included in the analysis, of which 145 were treated with H + P + taxane + carboplatin (TcbHP), 94 with H + P + taxane (THP) and 63 with sequential anthracycline and cyclophosphamide, followed by H + P + taxane (AC-THP). The overall tpCR rate was 64.9%, and those of TcbHP, THP, and AC-THP were 73.1%, 52.1%, and 65.1%, respectively. The tpCR rate of the hormone receptor (HR) negative group (80.3%) was higher than that of the HR positive group (52.1%). The overall bpCR rate was 73.5% and the apCR rate was 75.8%. In the univariate analysis, HR, HER2 status and treatment regimen were related factors that affected tpCR. In the multivariate analysis, HR, HER2 status and treatment regimen were independent predictors of tpCR (P < .001, P < .001 and P = .009). The levels 3 and 4 toxicities rates of TcbHP were slightly higher than those of THP and AC-THP. HP combined with chemotherapy has achieved a high pCR rate. The TcbHP regimen had the highest pCR. HR-negative tumors demonstrated a higher pCR. HR, HER2 status and treatment regimen were independent predictors of tpCR. The adverse reactions are controllable.