Predictors of pathologic complete response in triple‑negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and meta-analysis

Preoperative neoadjuvant chemotherapy (NAC) is a commonly employed treatment strategy for triple-negative breast cancer (TNBC). Various clinical factors may influence the likelihood of achieving a pathological complete response (pCR) following NAC. This study conducted a meta-analysis to identify factors associated with pCR to inform clinical decision-making. EMBASE, PubMed, WOS, Scopus databases were selected as the information sources to identify studies published before July 1, 2025. Predefined inclusion and exclusion criteria were applied, and the quality of included studies was assessed. Commonly reported factors were subjected to meta-analysis. Thirteen studies published between 2011 and 2025 were included, with eight published before 2020 and five thereafter. Seven potential influencing factors were analyzed, including individual characteristics, pathological features, and serum biomarkers. The pooled results indicated that clinical tumor stage (OR (odds ratio) = 0.35, 95% CI: 0.21-0.59, p = 0.032), Ki-67 expression (OR = 2.91, 95% CI: 1.64-5.16, p < 0.001), BRCA1/2 mutation status (OR = 1.95, 95% CI: 1.04-3.66, p = 0.037), and neutrophil-to-lymphocyte ratio (NLR) (OR = 5.61, 95% CI: 2.05-15.34, p < 0.001) were significantly associated with pCR. In contrast, age at diagnosis, histological grade, and nodal status were not statistically significant predictors. The likelihood of achieving pCR in TNBC patients undergoing NAC is significantly associated with clinical stage, Ki-67 expression, BRCA1/2 mutation status, and NLR. These factors should be evaluated prior to chemotherapy to help tailor treatment strategies and optimize therapeutic outcomes.