Abstract 2320: Cardiovascular disease mortality among breast cancer survivors in Puerto Rico: 2004-2019

Abstract Purpose: Cancer and Cardiovascular disease (CVD) are the two leading causes of death in both the United States and Puerto Rico (PR). Breast cancer (BC) survivors, considered since the time at diagnosis, face an elevated risk of CVD mortality, largely due to the cardiotoxic effects of cancer treatments and the presence of shared cardiometabolic risk factors with BC. However, there is a need for studies examining the risk of CVD mortality specifically among BC survivors in PR, one of the most rapidly aging populations in the world. This study aims to assess and compare the risk of CVD mortality among BC survivors and the general population in PR from 2004 to 2019. Methods: Data on BC survivors were obtained from the PR Central Cancer Registry for the period 2004 to 2019. Follow-up started approximately 12 months after diagnosis to account for treatment completion and extended through 2021. Standardized Mortality Ratios (SMRs) were calculated to compare CVD mortality risk between BC survivors and of the general population of women in PR aged 18 and older. The expected number of deaths was determined using age-, sex- and calendar year-specific mortality rates from the general population, obtained from the National Vital Statistics System. Results: The overall SMR for CVD mortality among BC survivors was 2.18 (95% CI: 1.99-2.38), with 470 observed, compared to 215.89 expected CVD deaths during the study period. The total person-years at risk amounted to 66, 388. A significant positive trend in increased risk of CVD mortality was observed by calendar year (p < 0.001), starting with a SMR of 1.51 (95% CI: 1.13-2.03) in 2004 and peaking in 2019 (SMR: 8.39; 95% CI: 4.64-15.15). Women under 60 years of age faced a particularly elevated risk (SMR: 8.48; 95% CI: 5.82-12.37), with SMRs declining to 1.73 (95% CI: 1.53-1.95) in women over 80 years of age. Conclusion: Our findings reveal a significantly elevated CVD mortality risk among BC survivors in PR, particularly in younger survivors, compared to the general population. Increasing SMRs over time highlight the importance of understanding cardiometabolic risk factors and stress-related social drivers throughout survivorship to guide targeted interventions for improving cardiovascular health. Citation Format: Carola T. Sánchez-Díaz, Genesis Rodriguez-Ortiz, Liliana Castro-JImenez, Barbara Segarra-Vazquez, Francisco Cordova, Vivian Colón-Lopez, Cynthia Perez-Cardona. Cardiovascular disease mortality among breast cancer survivors in Puerto Rico: 2004-2019 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2320.