Abstract P5-11-26: Stage-Based Survival Analysis in the TRIple-Negative Breast Cancer PrOspective Registry in MiddLe East AfrIca (TRIPOLI) Study

Abstract Background: Globally, triple negative breast cancer (TNBC) accounts for ∼15% of all breast cancer cases and some retrospective studies have suggested an advanced presentation and poorer outcomes in the Middle East and North African countries. This study aims to address the lack of reliable treatment and efficacy data in this region. Methods: TRIPOLI is a prospective multinational study from 17 institutions in 9 Arab countries including newly diagnosed patients with early TNBC (eTNBC) followed for a total of 3 years and patients with locally advanced/metastatic TNBC (la/mTNBC) followed for a total of 2 years. Herewith, we report survival analyses by stage in all patients and by pathological complete response (pCR) in eTNBC patients that received neoadjuvant chemotherapy (NAC) and surgery. Survival analyses include overall survival (OS), real-world progression-free survival (rwPFS) and real-world event-free survival (rwEFS). RwEFS was defined as the time from treatment initiation for eTNBC until the date of recurrence or death by any cause. Results: We report the data of 702 patients recruited between 2017 to 2019. Breakdown of patients by stage is as follows: 57 (8.1%) with stage I, 349 (49.7%) with stage II, 228 (32.5%) with stage III and 68 (9.7%) with stage IV disease. Of the 573 evaluable patients with eTNBC, the 3-year rwEFS rate was 96.3% in patients with stage I, 81.0% in patients with stage II and 66.5% in patients with stage III (excluding stage IIIc) (p<0.0001). Of the 99 evaluable patients with la/mTNBC, rwPFS was reported at 37.4%. The estimated 3-year OS rate for eTNBC patients was 100% for stage I, 94% for stage II and 87% for stage III (excluding stage IIIc). The median OS for patients with stage IIIc/IV was 20 months. As reported in Interim Analysis-2, 205 (39.5%) of 519 patients with eTNBC received NAC and surgery, with a pCR rate of 33.2%. The rwEFS rate was 82.4% in patients that achieved pCR versus 57.6% of patients that did not achieve pCR (p=0.0004). Deaths were reported in 9 (13.2%) patients that achieved pCR and in 16 (11.7%) that did not achieve pCR. At 3-year follow-up, OS did not achieve the pre-specified boundary for statistical significance.Conclusion: Among patients with early and locally advanced/metastatic TNBC, the survival outcomes decrease with higher stages. In patients who received NAC and surgery, achieving a pCR was associated with a higher statistically significant rwEFS compared to those who did not achieve pCR. These findings highlight the importance of early detection and effective treatment strategies for TNBC in the Arab countries, with a particular emphasis on the neoadjuvant approach to improve outcomes. Citation Format: Loay Kassem, Bernadette Pöllinger, Maja Velkovski-Rouyer, Alaa Kandil, Heba El Zawahry, Hikmat Abdel-Razeq, Hesham Elghazaly, Suad Al Kharusi, Manal Moawad, Salah Fayaz, Ahmed Saadeddin, Huda A. Alabdulkarim, Rasha Aboelhassan, Hassan Errihani, Tahseen Al Rubai, Salha Bujassoum Al Bader, Nashwa Abdelraouf Nashwa Raouf, Nagi El Saghir, Jean-Marc Nabholtz, Mohamed El Leithy, Pari Shahrezaei, Christine König, Nassib Neaimeh, Marwan Ghosn, Hamdy A. Azim. Stage-Based Survival Analysis in the TRIple-Negative Breast Cancer PrOspective Registry in MiddLe East AfrIca (TRIPOLI) Study [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 P5-11-26.