Determinants of survival in triple-negative breast cancer: A clinicopathological study from an Indonesian Cancer Center

A BSTRACT Objectives: Triple-negative breast cancer (TNBC) outcomes in Southeast Asian and resource-limited settings remain underreported. This study evaluated factors associated with 3-year overall survival (OS), event-free survival (EFS) in stage I–IIIC disease, and progression-free survival (PFS) in stage IV disease. Materials and Methods: This retrospective cohort included 290 women with TNBC diagnosed at an Indonesian national cancer center between 2015 and 2021. OS was analyzed in all patients, EFS in stage I–IIIC patients, and PFS in stage IV patients. Survival was administratively censored at 36 months. Prognostic factors were assessed using univariable and multivariable Cox regression. Results: The 3-year Kaplan–Meier OS rate was 57.1%. Among stage I–IIIC patients, 3-year EFS was 55.6%; among stage IV patients, 3-year PFS was 13.9%, with a median PFS of 15.0 months. In the full cohort, higher education was associated with improved OS, whereas stage IV disease and thrombocytosis were associated with poorer OS. In stage I–IIIC disease, higher education was associated with improved EFS, while stage III disease and thrombocytosis were associated with poorer EFS. In exploratory stage IV analyses, obesity was associated with longer PFS and a first-degree family history of breast and/or ovarian cancer with shorter PFS. Conclusion: TNBC survival in this Indonesian cohort was associated with disease extent, thrombocytosis, and educational attainment as a surrogate social determinant, with distinct prognostic patterns across disease settings. These readily available markers may support risk stratification, but require validation and should be interpreted as associations, not causal effects.