Abstract P2-08-15: From Clinical Trials to Real-World Practice: Treatment Regimens, Pathological Complete Response Rates, and the Addition of Platinum Salts in Patients with Triple- Negative Breast Cancer

Abstract Purpose: Comprehensive real-world data on current treatment methods for early triple- negative breast cancer (TNBC) are limited. To validate optimal treatments demonstrated in randomized controlled trials analyses of data obtained from routine clinical care are essential. This study aims to analyze the treatment outcomes of patients with early-stage TNBC using data from a large, population-based cancer registry. Methods: This retrospective, non-interventional, population-based singlemulti-center study utilized data from TNBC patients diagnosed between January 1, 2010, and December 31, 2018, at the cancer registry Tumor Centre Regensburg. The data included demographics, pathology, treatment, recurrence, and survival, with follow-up extending to December 2023. 319 patients with TNBC who received neoadjuvant chemotherapy were identified. The outcomes measured were pathologic complete response (pCR), overall survival (OS), and recurrence-free survival (RFS). Results: A total of 319 patients were included. Of these, 132 (41.4%) received neoadjuvant chemotherapy (NACT) with Epirubicin/Cyclophosphamide (EC) and Paclitaxel (EC-T), 74 (23.2%) received NACT with EC-T and Platinum (EC-P/T), and 22 (6.9%) received NACT with EC-P/nabPaclitaxel (EC-P/nabP). Other NACT protocols were administered to 91 (28.5%) patients. A pCR was achieved in 49.8% of NACT patients, with a rate of 37.1% in the subgroup without platinum. The addition of platinum significantly increased the pCR rate to 54.1% compared to EC-T (OR 3.476, 95% CI 1.655-7.300, p=0.001). EC-P/nabP led to a significant increase in the pCR rate to 77.3% (OR 8.767, 95% CI 2.421-31.744, p<.001). Conclusion: This real-world evidence study demonstrates the increased use of platinum- based neoadjuvant therapies in alignment with current clinical guidelines, resulting in higher pCR rates. This trend is consistent with findings from randomized controlled trials. Platinum salts should be a standard of care in the chemotherapy regiments for patients with TNBC. Citation Format: Maria Eleni Hatzipanagiotou, Verena Zeltner, Michael Gerken, Miriam Pigerl, Sophie Räpple, Jonas Roth, Olaf Ortmann, Monika Klinkhammer-Schalke, Stephan Seitz. From Clinical Trials to Real-World Practice: Treatment Regimens, Pathological Complete Response Rates, and the Addition of Platinum Salts in Patients with Triple- Negative Breast Cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P2-08-15.