Real-World Outcomes of Neoadjuvant Pembrolizumab plus Chemotherapy in Early-Stage Triple-Negative Breast Cancer: A Multicenter Study from Türkiye
Rashad Ismayilov1, Arzu Oğuz1, Arif Akyıldız2, Engin Hendem2, Elvina Almuradova3, Özden Altundağ1, Kadri Altundağ41Department of Medical Oncology, Baskent University Faculty of Medicine, Ankara, Türkiye, 2Department of Medical Oncology, Erzincan Binali Yıldırım University Faculty of Medicine, Erzincan, Türkiye, 3Department of Medical Oncology, Memorial Goztepe Hospital, İstanbul, Türkiye, 4MKA Breast Cancer Clinic, Tepe Prime, Ankara, Türkiye
Objectives: Neoadjuvant pembrolizumab plus chemotherapy is the standard of care for high-risk early-stage triplenegative 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. Keywords: Breast Cancer, Neoadjuvant Therapy, Pembrolizumab, Real-World Evidence, Triple-Negative
Cite This Article
Ismayilov R, Oğuz A, Akyıldız A, Hendem E, Almuradova E, Altundağ Ö, Altundağ K. Real-World Outcomes of Neoadjuvant Pembrolizumab plus Chemotherapy in Early-Stage Triple-Negative Breast Cancer: A Multicenter Study from Türkiye. EJMI. 2026; 10(2): 171-178
Corresponding Author: Rashad Ismayilov