Abstract 81: Survival Disparities in Colombian Breast Cancer: A Prospective Cohort Study on Incident Cases Diagnosed Between 2012 and 2019 in Three Urban Cities

Abstract Purpose: To identify predictors of overall survival in a prospective cohort of Colombian patients with breast cancer diagnosed between 2012 and 2019. Methods: A cohort of 330 women, with at least 3 years of residence and diagnosed with incident breast cancer in three oncology clinics of Barranquilla, Cali, and Medellin was followed from 2012 to 2024. Women were recruited and interviewed before treatment. Clinical and pathological records were manually reviewed from both physical and digital sources. Ancestry was defined by genotyping 106 informative markers in DNA from blood cells. Death from any cause was ascertained by annual telephone calls to cases or most near family members. Vital status was independently verified in central public databases. The effect on 5-year survival of sociodemographic factors, health care social security scheme [subsidized (the poorest population) and contributory (medium and high incomes population)], clinical characteristics, tumor molecular subtype and genetic ancestral component was evaluated by Hazard Ratios-HR using the Cox model. This analysis includes 59 of 70 deaths and 244 of 260 censored cases. Results: Overall, 5-year survival was 79% (95%CI, 74–83). Survival estimates for women in high, middle, and low socioeconomic strata were 79% (95%CI 63–89), 67% (95%CI 55–77), and 57% (95%CI 46–67), and for women of the subsidized and the contributory health care regime were 69% (95%CI 58–78) and 82% (95%CI 76–86) respectively, (p=0.007). After adjusting by all variables women residing in Barranquilla (HR 2.40, 95%CI 1.1–5.21) and Cali (HR 2.45, 95%CI 1.12–5.36), with a locally advanced or metastatic stage (III, and IV) at diagnosis (HR 4.8, 95%CI 2.6–8.90), a triple-negative tumor (HR 3.8, 95%CI: 2.0–7.20) and low European ancestry (HR 1.78, 95%CI 1.0–3.12) have a higher risk of death than women of Medellin, with an early stage at diagnosis, luminal type tumor, and high European ancestry. The best predictors for death in the stepwise Cox proportional hazards model including city, locally advanced or metastatic stage (HR 5.33, 95%CI 3.02–9.4), triple-negative tumor and low European ancestry. Conclusion: Breast cancer survival in Colombia shows regional disparities despite the implementation of a national early detection program since 2012. The results also underscore the need for specific interventions tailored to improve breast cancer early detection in disadvantaged socioeconomic backgrounds in Colombia. Citation Format: Maria C. Agudelo, Samuel Agudelo, Gonzalo Angel, Carlos Andres Ossa, Mauricio Borrero, Jorge Madrid, Roberto Jaramillo, Israel Diaz, Angel Hernandez, Alvaro Guerrero, Luis Alfonso Gonzalez, Edgar Navarro, Gloria Ines Sanchez. Survival Disparities in Colombian Breast Cancer: A Prospective Cohort Study on Incident Cases Diagnosed Between 2012 and 2019 in Three Urban Cities [abstract]. In: Proceedings of the 13th Annual Symposium on Global Cancer Research; 2025 Sep 16. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(12_Suppl):Abstract nr 81.