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Cardiovascular disease risk following radiotherapy among breast cancer survivors: a nationwide cohort study in South Korea

Year: 2025

Type: article

Abstract: BACKGROUND: While radiotherapy (RT) improves breast cancer survival outcomes, concerns persist regarding radiation-induced cardiovascular complications. We aimed to evaluate the incidence and risk of radiation-associated cardiovascular disease (CVD) among breast cancer survivors. METHODS: This population-based retrospective cohort study included 38,045 female breast cancer survivors in South Korea who survived at least 1 year following diagnosis between 2012 and 2019. Cumulative incidence of CVD was estimated using the cumulative incidence function accounting for competing risks. Hazard ratios (HRs) for radiation-associated CVD were calculated using cause-specific Cox proportional hazards models with adjustments for potential confounders. RESULTS: Among the study population, 67.8% received RT. The RT group was younger at diagnosis, had fewer distant-stage cancers, and lower prevalence of pre-existing cardiovascular conditions compared to the non-RT group. The 9-year cumulative incidence of overall CVD was 32.8%, with higher rates in the non-RT group. RT was not significantly associated with increased risk of overall heart disease (HR: 0.94; 95% CI 0.88-1.01) or specific subtypes. No significant differences were observed between RT techniques. While no significant interaction was observed between RT and chemotherapy for overall heart disease risk (p = 0.2641), a significant interaction was identified for heart failure (p = 0.0013); patients receiving both RT and chemotherapy exhibited an increased risk (HR: 1.31; 95% CI 1.03-1.65) compared to those receiving neither treatment. CONCLUSIONS: RT was not significantly associated with increased overall CVD risk, nor were there significant differences based on RT technique or its combination with chemotherapy for most cardiac outcomes. However, combined RT and chemotherapy significantly elevated heart failure risk, suggesting a potential interaction effect. Given the relatively short follow-up period, cautious interpretation of these results is warranted.

Source: Breast Cancer Research

DOI: 10.1186/s13058-025-02178-4

Authors: Jeeyoung Lee, Eun Young Park, Won Jin Lee

Institutions: Korea University, Korea University Medical Center

Language: English

Topic: Chemotherapy-induced cardiotoxicity and mitigation

Subfield: Cardiology and Cardiovascular Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $4,190