Abstract B126: Cardiovascular disease mortality among multiple myeloma patients treated with chemoimmunotherapy, 2000-2021

Abstract Background: Survival for multiple myeloma (MM) patients treated with chemoimmunotherapy have significantly improved over the past two decades. Cardiovascular disease (CVD) remains an important survivorship concern for MM patients in part due to older age, comorbidities, and treatment-related cardiotoxicity. Despite well-established racial and ethnic disparities in CVD mortality in the general U.S. population, there is a paucity of data among MM patients. Our study characterized CVD mortality among MM patients by race and ethnicity and across patient and tumor characteristics. Methods: Using SEER 17 Registries, we identified 53,910 individuals diagnosed with first primary MM between 2000-2020 (followed until 2021) and treated with chemotherapy/immunotherapy. We assessed the hazard ratio (HR) of CVD mortality using Cox proportional hazards models with attained age as the time scale for Hispanic (all races; N=7,136 [13%]), non-Hispanic (NH) American Indian/Alaska Native (AI/AN, N=230 [0.4%]), NH Asian American (Asian American, N=3,057 [6%]), NH Black (Black, N=10,129 [19%]), NH Native Hawaiian and Pacific Islander (NHPI, N=336 [0.6%]), compared with NH White (White, N=33,022 [61%]) patients. We quantified CVD HRs overall and stratified by sex, age at MM diagnosis, years since MM diagnosis, county-level median household income quartiles, and urbanicity. We then estimated cumulative CVD mortality accounting for competing events (non-CVD deaths) by race and ethnicity. Results: Compared to White patients, CVD mortality rates were significantly higher among Black (HR=1.48, 95%CI=1.35-1.62) and NHPI (HR=2.00, 95%CI=1.30-3.08) patients but not AI/AN (HR=1.35, 95%CI=0.80-2.29), Asian American (HR=1.02, 95%CI=0.86-1.21), Hispanic (HR=1.08, 95%CI=0.96-1.22) patients. Among Black patients, elevated risks of CVD mortality were consistent across patient characteristics but most notable for the youngest patients (aged 20-49 years, HR=2.54, 95%CI=1.64-3.93) and those living in non-metropolitan counties (HR=2.13, 95%CI=1.68-2.70). Among NHPI patients, the highest risk of CVD mortality were observed for those aged 50-64 years (HR=3.84, 95%CI=2.04-7.22), male sex (HR=2.13, 95%CI=1.28-3.54), and those residing in lower income (HR=3.56, 95%CI=1.76-7.19) and non-metropolitan counties (HR=2.81, 95%CI=1.02-7.77). By 10 years after MM diagnosis, the greatest absolute CVD mortality risks were observed among AI/AN (8.52%, 95% CI=3.95-13.10), Black (7.77%, 95%CI=7.15-8.38), and NHPI (7.19%, 95%CI=4.10-10.29) patients followed by White (6.49%, 95%CI=6.18-6.79), Asian (5.82%, 95%CI=4.82-6.82), and Hispanic (5.63%, 95%CI=4.98-6.28) patients. Conclusions: Our findings revealed striking racial and ethnic difference in CVD mortality for MM patients, most notable for Black and NHPI patients. Future research should consider the impact of comorbidities, modifiable CVD risk factors, alternatives to cardiotoxic cancer treatment, and strategies to improve clinician awareness of high-risk patients and ultimately reduce CVD mortality disparities for MM patients. Citation Format: Jacqueline B. Vo, Martha S. Linet, Keli’i Shontell, Wayne R. Lawrence, Kekoa Taparra, Jaimie Z. Shing, Paloma R. Mitra, Rochelle E. Curtis, Sara J. Schonfeld, Graça M. Dores, Lindsay M. Morton. Cardiovascular disease mortality among multiple myeloma patients treated with chemoimmunotherapy, 2000-2021 [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 B126.