Different Chemotherapy Regimens and Pathologic Complete Response in Triple-Negative Breast Cancer: An Updated Network Meta-Analysis of Phase 3 Trials

Background and Objectives: Currently, the standard treatment for non-metastatic triple-negative breast cancer (TNBC) consists of a systemic neoadjuvant (or perioperative) anthracycline plus taxane-based chemotherapy, delivered either sequentially or concomitantly. We performed a network meta-analysis (NMA) to compare the relative efficacy of different neoadjuvant treatments for TNBC in terms of pathologic complete response (pCR). Materials and Methods: The MEDLINE, Embase, and Cochrane databases were searched from database inception to 1 November 2023. Randomized clinical trials were used that enrolled adults with stage I-III TNBC and provided data on pCR defined as residual ypT0/TisN0M0. Between-group comparisons were estimated using risk ratios (RRs) with 95% credible intervals (95% CrIs). The primary outcome was the pCR rate. Results: 1129 citations were screened, and 12 randomized clinical trials were included. In Bayesian comparisons, all regimens, except anthracycline/taxanes plus gemcitabine or capecitabine, resulted in a higher pCR than the standard regimen in both direct and indirect comparisons. In particular, immunotherapy-based regimens resulted in more than double the pCR compared to historical regimens (RR = 2.3, 95% CI 1.9-2.9) and ranked as being the optimal regimen with a probability of 97%. Disease-free survival was better for immune checkpoint inhibitor-based chemotherapy (HR = 0.36, 95% 1.21-2.09) than for historical regimens. Conclusion: This meta-analysis confirmed that incorporating immunotherapy with neoadjuvant platinum-based chemotherapy is the best option to guarantee remarkable pathologic downstaging and improve clinical outcomes.