Comparison of the Efficacy and Safety of Docetaxel-Trastuzumab-Pertuzumab (DTP) with Standard 4-Doxorubicin and Cyclophosphamide (AC)-Taxan-Trastuzumab-Pertuzumab in Neoadjuvant Treatment of Locally Advanced Human Epidermal Growth Factor Receptor 2 (HER-2) Positive Breast Cancer: a Turk Oncology Group (TOG) study.

Abstract

Abstract Introduction:Human epidermal growth factor receptor 2 (HER2) overexpression is a characteristic observed in 18%–20% of all breast cancer cases. While some clinics have adopted abbreviated neoadjuvant treatment for HER2-positive breast cancer, there remains a shortage of comprehensive clinical data to support this practice. One of the primary considerations in the treatment of HER2-positive breast cancer is the need for regimens that minimize cardiac toxicity while not compromising survival outcomes. This issue continues to be a topic of discussion within the medical community. Methods:Retrospectively analyzed were the data of HER2-positive breast cancer patients, aged ≤65 years, with left ventricular ejection fraction (LVEF) ≥50% who received neoadjuvant chemotherapy and underwent surgery at 10 different oncology centers in Türkiye between October 2016 and December 2022. Results: A total of 142 patients were included in the study. The treatment arms were divided into 4 to 6 cycles of docetaxel/trastuzumab/pertuzumab (DTP) for arm A, 4 cycles of adriamycin/cyclophosphamide (AC) followed by 4 cycles of taxane/TP for arm B. There were 50 patients (35.2%) in arm A and 92 patients (64.8%) in arm B. The mean age of the patients in arm A was 53 years (±11, SD), while in arm B it was 48 years (±11, SD). The median follow-up of all of the patients was 19.9 months (95% CI: 17.5–22.3). Median disease-free survival (DFS) was not reached in either treatment arm. The 3-year DFS rates for treatment arms A and B were 90.0% and 83.8%, respectively, and the survival outcomes between the groups were similar (p = 0.34). Furthermore, the pathologic complete response (pCR) rates were similar in both treatment arms, at 50.0% and 51.1%, respectively (p = 0.90). During the treatment period, the LVEF decline was seen in 3 patients (6%) in arm A and 11 patients (12%) in arm B, but the difference between the groups did not reach statistical significance (p = 0.37). Although the LVEF decreases were asymptomatic in both treatment arms, the rate of LVEF decrease was between 11% and 20% in 2 patients (2.2%) in arm B. Discussion/Conclusion: This study supports shortened neoadjuvant treatment of HER2-positive breast cancer, a common practice in some clinics. Given the similar DFS and pCR rates between DTP and AC-taxan/TPtreatments, DTP may avoid the severe toxicities associated with standard combined chemotherapy regimens.