Pathological Complete Response to Nab-Paclitaxel-Containing Neoadjuvant Regimens in Early Triple-Negative Breast Cancer: A Systematic Review and Meta-Analysis.

Background: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited targeted treatment options. This systematic review and meta-analysis evaluated pathological complete response (pCR) outcomes associated with nab-paclitaxel-containing neoadjuvant regimens incorporating platinum chemotherapy and/or immune checkpoint inhibitors in early-stage TNBC. Methods: PubMed/MEDLINE, Scopus, Google Scholar, CENTRAL, and Embase were searched for eligible publications within the review window (January 2005 through 31 March 2026). Eligible studies were randomized or prospective clinical studies of non-metastatic TNBC receiving nab-paclitaxel-containing neoadjuvant regimens with platinum and/or immune checkpoint inhibition. Randomized checkpoint-inhibitor comparisons were synthesized as risk ratios; eligible prospective non-randomized pCR datasets were synthesized using a logit random-effects model with REML variance estimation and Hartung-Knapp-Sidik-Jonkman inference. Results: The final evidence base comprised 21 unique eligible prospective studies. Four clinically comparable randomized checkpoint-inhibitor trials (n = 1228) yielded a pooled pCR risk ratio of 1.25 (95% CI 1.12-1.41; I2 = 0%). Fourteen prospective non-randomized datasets (n = 539; 320 pCR events) yielded a pooled pCR proportion of 59.8% (HKSJ 95% CI 53.8-65.6%; I2 = 32.7%; τ2 = 0.0559). Conclusions: Within nab-paclitaxel-containing neoadjuvant backbones, checkpoint-inhibitor addition was associated with higher pCR in randomized comparative evidence. The approximately 60% pooled pCR proportion from prospective non-randomized studies is descriptive and should not be interpreted as a cross-regimen comparison because of clinical and methodological heterogeneity.