Skip to main content
eScholarship
Open Access Publications from the University of California

UC San Diego

UC San Diego Previously Published Works bannerUC San Diego

Modern Radiation Therapy and Cardiac Outcomes in Breast Cancer.

  • Author(s): Boero, Isabel J
  • Paravati, Anthony J
  • Triplett, Daniel P
  • Hwang, Lindsay
  • Matsuno, Rayna K
  • Gillespie, Erin F
  • Yashar, Catheryn M
  • Moiseenko, Vitali
  • Einck, John P
  • Mell, Loren K
  • Parikh, Sahil A
  • Murphy, James D
  • et al.
Abstract

Purpose

Adjuvant radiation therapy, which has proven benefit against breast cancer, has historically been associated with an increased incidence of ischemic heart disease. Modern techniques have reduced this risk, but a detailed evaluation has not recently been conducted. The present study evaluated the effect of current radiation practices on ischemia-related cardiac events and procedures in a population-based study of older women with nonmetastatic breast cancer.

Methods and materials

A total of 29,102 patients diagnosed from 2000 to 2009 were identified from the Surveillance, Epidemiology, and End Results-Medicare database. Medicare claims were used to identify the radiation therapy and cardiac outcomes. Competing risk models were used to assess the effect of radiation on these outcomes.

Results

Patients with left-sided breast cancer had a small increase in their risk of percutaneous coronary intervention (PCI) after radiation therapy-the 10-year cumulative incidence for these patients was 5.5% (95% confidence interval [CI] 4.9%-6.2%) and 4.5% (95% CI 4.0%-5.0%) for right-sided patients. This risk was limited to women with previous cardiac disease. For patients who underwent PCI, those with left-sided breast cancer had a significantly increased risk of cardiac mortality with a subdistribution hazard ratio of 2.02 (95% CI 1.23-3.34). No other outcome, including cardiac mortality for the entire cohort, showed a significant relationship with tumor laterality.

Conclusions

For women with a history of cardiac disease, those with left-sided breast cancer who underwent radiation therapy had increased rates of PCI and a survival decrement if treated with PCI. The results of the present study could help cardiologists and radiation oncologists better stratify patients who need more aggressive cardioprotective techniques.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View