Anthracycline-containing versus anthracycline-free carboplatin-based regimens in early-stage triple-negative breast cancer: real-world outcomes

Abstract

Triple‑negative breast cancer (TNBC) is an aggressive disease with poor survival outcomes. With the integration of immunotherapy, the optimal neoadjuvant chemotherapy backbone remains poorly defined. We examined real-world treatment patterns and response rates among patients receiving a carboplatin-based regimen, with or without anthracyclines. In this retrospective cohort study, women diagnosed 2012–2024 with stage I-III TNBC who received neoadjuvant carboplatin plus taxane (CbT) or CbT with anthracyclines (AC-CbT) were identified from electronic health records data from 10 sites within the Greater Plains Collaborative network. Registry-recorded physician assessment of pathologic complete response (pCR) was the primary outcome. Multivariable logistic regression evaluated whether adding anthracyclines to carboplatin-based treatment was associated with pCR. Among 878 patients with TNBC, 41.2% received CbT and 58.8% received AC-CbT. Overall, 46% received pembrolizumab, 11.7% in the CbT group and 66.3% in the AC-CbT group. On univariate analysis, pCR rates did not differ between the CbT and AC-CbT groups (47.2% vs. 51.9%, OR = 1.21, 95%CI 0.92–1.58), among patients who underwent surgery. In multivariate adjusted analyses, AC-CbT was not associated with higher odds of pCR (aOR = 1.05, 95%CI 0.69–1.59), among patients who underwent surgery. Other patient characteristics associated with pCR included pembrolizumab use, higher-grade disease, lower stage, and age at diagnosis (40–49 versus 60+). Use of carboplatin-containing regimens increased substantially over time. In this real-world cohort, addition of anthracycline to carboplatin-containing regimen was not associated with an improvement in pCR rates. These findings suggest clinical equipoise regarding anthracycline omission in early-stage TNBC, to be validated in prospective trials. Additional work evaluating adherence, toxicity, and long-term outcomes is needed.