Abstract PS4-10-28: Neoadjuvant Chemoimmunotherapy in Early-Stage TNBC: Real-World Analysis of Predictors of pCR and Survival

Abstract Background: Triple-negative breast cancer (TNBC) is one of the most challenging breast cancer subtypes to manage due to its aggressive biology, high recurrence risk, and limited targeted treatment options. Neoadjuvant chemotherapy plus pembrolizumab (NACP) has become a new standard aimed at increasing pathological complete response (pCR) rates and improving long-term survival. This study aims to evaluate pCR and survival outcomes in early-stage TNBC patients receiving NACP based on real-world data, and to identify clinicopathological factors predictive of pCR and survivals. Methods: This multicenter retrospective study included 164 early-stage TNBC patients treated with NACP, followed by surgery. Demographic, clinical, radiological, and pathological data were analyzed. The primary endpoint was the pCR rate; secondary endpoints included disease-free survival (DFS) and overall survival (OS). Predictors of pCR and survivals were evaluated using multivariate logistic and Cox regression analyses, respectively. Results: Among 164 patients with a median follow-up of 49.2 months, the pCR rate was 60.4%. Recurrence and mortality rates were 18.3% and 3.0%, respectively. In the univariate analyses for DFS, radiological T stage at diagnosis (p=0.001), carboplatin administration schedule (p