Rashad ISMAYILOV, Arzu OĞUZ, Arif AKYILDIZ, Engin HENDEM, Elvina ALMURADOVA, Özden ALTUNDAĞ, Kadri ALTUNDAĞ
Eurasian Journal of Medical Investigation - 2026;10(2):171-178
Objectives: Neoadjuvant pembrolizumab plus chemotherapy is the standard of care for high-risk early-stage triple-negative breast cancer (eTNBC), yet real-world data remain limited. We evaluated the effectiveness and safety of this regimen in Türkiye. Methods: This multicenter retrospective cohort study included consecutive adults with stage I-III eTNBC treated with neoadjuvant pembrolizumab plus chemotherapy between 2022 and 2025 at four centers. Primary endpoints were pathological complete response (pCR) and event-free survival (EFS). Safety was assessed using CTCAE v5.0 criteria. Results: Sixty-one women were included (median age 44 years); 37.7% had stage III disease and 62.3% had nodal involvement. Most tumors were grade 3 (78.7%) with high Ki-67 (>=40% in 85.2%). Planned neoadjuvant chemotherapy was completed in 91.8% of patients. The pCR rate was 62.3%. At a median follow-up of 12.2 months, five EFS events (8.2%) occurred. Estimated 12- and 18-month EFS rates were 91.4% and 86.8%. pCR was the only significant predictor of EFS (1-year EFS 100% vs. 75.5%, p = 0.001). Grade >=3 adverse events were mainly hematologic, while severe immune-related toxicity was rare. Conclusion: Neoadjuvant pembrolizumab plus chemotherapy demonstrated high pCR rates and preliminary favorable early survival outcomes in real-world practice, confirming pathological response as a key driver of prognosis in eTNBC.
