AHA Scientific Sessions 2026 Abstract · Nov 2, 2026
Disparities and Impact of Laterality on Cardiovascular Mortality Among Long-Term Female Breast Cancer Survivors: Insights from the SEER Database
By Ubogun O, William S, Ubogun E et al.
Background: Breast cancer survival has improved with newer therapy, with CVD emerging as the leading non-cancer cause of death in long-term survivors. Left-sided breast irradiation historically confers greater cardiac radiation exposure than right-sided treatment. Socioeconomic disparities and the impact of laterality is incompletely characterised. Methods: We conducted a retrospective analysis of female breast cancer survivors from the SEER database (2000-2022). We included women aged ≥20 years with breast cancer (localised, regional, or distant stage) who survived ≥60 months post-diagnosis (N = 747,789). The primary outcome was CVD mortality. Cumulative incidence functions (CIF) were extracted at 10, 15, and 20 years post-survivorship milestone using the Aalen-Johansen method. Fine-grey subdistribution hazard models (sHR; 95% CI) were constructed to evaluate the independent effect of age, income, race/ethnicity, geographic location, cancer stage, treatment modality and effect of laterality on CVD mortality. Results: Among survivors, 35,070 CVD deaths occurred over a maximum follow-up of 215 months. The overall cumulative incidence of CVD mortality by Fine-Grey competing risks analysis was 9.63%, rising progressively from 2.64% at year 10 to 5.35% at year 15 and 8.03% at year 20 post-survivorship milestone. CVD mortality increased sharply with age at diagnosis: from 0.79% in women aged 20-39 years to 27.08% in those aged 80+ years (sHR 61.83; 95% CI: 45.94-83.22; p < 0.001). Socioeconomic disparities were significant: low-income survivors (<$60,000) had an 11.03% cumulative CVD incidence vs. 8.61% in the highest-income group (>$100,000; sHR 1.39; p < 0.001). Rural survivors had higher CVD mortality than urban counterparts (11.23% vs. 9.36%; sHR 1.30; p < 0.001). Racial disparities revealed that non-Hispanic White (10.26%) and non-Hispanic Black survivors (9.84%) bore the highest CVD burden, while Hispanic (sHR 0.57; p < 0.001) and Asian/Pacific Islander (sHR 0.51; p < 0.001) survivors had significantly lower risk relative to non-Hispanic White women. Non-Hispanic Black survivors did not differ significantly from non-Hispanic White survivors (sHR 0.97; p = 0.44). An inverse relationship was observed between cancer stage and CVD mortality, as localised disease carried the highest cumulative incidence (10.47%), followed by regional (8.07%) and distant stages (4.58%). Among treatment modalities, surgery-only patients had the highest CVD incidence (13.11%), while combined chemotherapy plus radiation yielded the lowest (5.46%; sHR 0.29; p < 0.001). In the radiation-exposed cohort, left-sided breast irradiation showed no statistical difference in CVD mortality compared to right-sided irradiation (8.69% vs. 8.81%; sHR 1.05; p = 0.21). Conclusion: Socioeconomic disparities persist; hence, equity-centred care. Tumour laterality did not predict CVD mortality.