Oncologic Outcomes and Safety of Neoadjuvant Treatment with Anthracyclines Versus Anthracycline-Free Regimens in HER2-Positive Early Breast Cancer in a Colombian Cancer Center: An Observational, Analytical, Retrospective Study

Abstract

Background: There are no comparative trials between the two most common schemes in HER2-positive early breast cancer treatment; BERENICE (with anthracyclines) and TRAIN-2 (without anthracyclines). In this study, we investigated the pathological complete response (pCR) and safety events achieved with each. Methods: This analytical retrospective observational study included 111 patients with early and locally advanced HER-2-positive breast cancer who initiated neoadjuvant treatment with an anthracycline-based scheme (four cycles of doxorubicin and cyclophosphamide, followed by four cycles of taxane, trastuzumab, and pertuzumab = AC-THP) and a non-anthracycline scheme (carboplatin, weekly paclitaxel, trastuzumab, and pertuzumab for six–nine cycles = TCbHP) at the National Cancer Institute in Colombia, between April 2020 and December 2024. The primary endpoint was the pCR. Safety was analyzed in patients who received at least one treatment cycle. Results: A total of 51 patients received AC-THP and 60 TCbHP (89.6% of which received six cycles). The pCR was 58.3% in ACHTP and 60.4% in TCbHP (p = 0.84). As a descriptive analysis, with the anthracycline-based scheme, there was a trend toward a higher pCR in patients with T3-T4, positive nodal involvement (N+), and positive hormone receptor (HR+). Cardiac toxicity events during the neoadjuvant phase were 9.8% in ACTHP and 3.3% in TCbHP. Grade 2 neuropathy events were higher in patients with the TCbHP scheme, at 23.3%, versus 9.8% in ACTHP. Conclusions: We found similar pCR rates between the schemes with anthracyclines and without anthracyclines. It is still pertinent to discuss the risk–benefit of using anthracycline-based regimens in patients with HR+, T3-T4, and N+. The cardiac adverse events reported in our patients were similar to those reported in the BERENICE trial.