Abstract A117: Racial and ethnic disparities in cardiovascular disease mortality among breast cancer survivors in Puerto Rico and the United States, 2004–2019

Abstract Purpose: Cancer and cardiovascular disease (CVD) are the leading causes of death in both the United States (US) and Puerto Rico (PR), and breast cancer (BC) survivors may face elevated CVD mortality risk due to treatment-related cardiotoxicity and shared risk factors. Yet, little is known about the CVD burden among BC survivors on PR or how it compares to survivors across racial/ethnic groups in the US. Objective: To quantify and compare CVD mortality risk among BC survivors in PR and among racially and ethnically groups in the US, relative to the US general population. Methods: We analyzed data from women aged ≥18 years diagnosed with a first primary invasive BC between 2004 and 2019, using the PR Cancer Registry and SEER 17. Follow-up began 12 months post-diagnosis (to approximate treatment completion) and continued through December 31, 2021. Participants were categorized as PR Hispanics (n=470), and in the US, as non-Hispanic (nH) Whites (n=23,582), nH Blacks (n=3,292), US Hispanics (n=2,193), and Asian Americans, Native Hawaiians, Pacific Islanders, and American Indian/Alaska Natives (AANHPI/AIAN) (n=1,632). CVD mortality was defined using ICD-10 codes for diseases of the heart, cerebrovascular disease, atherosclerosis, and other vascular causes. Standardized mortality ratios (SMRs) and 95% CI were computed using age-, sex-, and calendar year-specific CVD mortality rates from the general populations of the US. SMRs were stratified by race/ethnicity, age at diagnosis, treatment, stage at diagnosis and calendar year. Results: Among 31,169 CVD deaths, 75.7% occurred among nH White BC survivors. PR Hispanic and AANHPI/AIAN survivors experienced significantly higher CVD mortality compared to the general US population (SMRs:1.27; 95% CI: 1.15–1.38 and 1.08; 95%CI: 1.03–1.13). Conversely, lower CVD mortality was observed among US Hispanic (SMR:0.83; 95% CI: 0.79–0.86) and nH White (SMR: 0.86; 95% CI: 0.85–0.88), with marginally elevated risks for nH Black (SMR: 1.03; 95% CI: 1.00–1.07). The highest disparities were observed among PR Hispanics aged 40–49, 50–59, and 60–69, who had 3.0-, 1.8-, and 1.8-fold increased CVD mortality risk, respectively. Similarly, AANHPI/AIAN survivors 40 and over 80 years had 2.5- and 1.2-fold increased risk, respectively. When stratified by stage at diagnosis, PR Hispanics had elevated CVD mortality at localized and regional stages. Black, AANHPI/AIAN, and White survivors with distant-stage disease experienced 2.2-, 2,2- and 1.3-fold higher mortality. US Hispanic and Whites with localized disease had reduced risk, and no risk was observed for distant-stage PR and US Hispanic survivors. Additionally, both PR Hispanic and nH Blacks demonstrated elevated risk across 3 of the 5 treatment modalities evaluated. Conclusions: PR Hispanic survivors face a significantly higher burden of CVD mortality than all US racial and ethnic groups, particularly among younger survivors. These findings underscore the urgent need for targeted, multilevel interventions to address CVD across the survivorship continuum in PR. Citation Format: Carola T. Sánchez-Díaz, Génesis Rodríguez-Ortiz, Liliana Castro-Jiménez, Lorraine N. Vélez-Torres, Bárbara Segarra-Vázquez, Francisco Córdova-Pérez, Vivian Colón-López, Cynthia Pérez-Cardona. Racial and ethnic disparities in cardiovascular disease mortality among breast cancer survivors in Puerto Rico and the United States, 2004–2019 abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A117.