Cardiovascular disease risk in a large, population-based cohort of breast cancer survivors

Purpose: To conduct a large, population-based study on cardiovascular disease (CVD) in breast cancer (BC) survivors treated in 1989 or later. Methods and Materials: A large, population-based cohort comprising 70,230 surgically treated stage I to III BC patients diagnosed before age 75 years between 1989 and 2005 was linked with population-based registries for CVD. Cardiovascular disease risks were compared with the general population, and within the cohort using competing risk analyses. Results: Compared with the general Dutch population, BC patients had a slightly lower CVD mortality risk (standardized mortality ratio 0.92, 95% confidence interval [CI] 0.88-0.97). Only death due to valvular heart disease was more frequent (standardized mortality ratio 1.28, 95% CI 1.08-1.52). Left-sided radiation therapy after mastectomy increased the risk of any cardiovascular event compared with both surgery alone (subdistribution hazard ratio (sHR) 1.23, 95% CI 1.11-1.36) and right-sided radiation therapy (sHR 1.19, 95% CI 1.04-1.36). Radiation-associated risks were found for not only ischemic heart disease, but also for valvular heart disease and congestive heart failure (CHF). Risks were more pronounced in patients aged <50 years at BC diagnosis (sHR 1.48, 95% CI 1.07-2.04 for left-vs right-sided radiation therapy after mastectomy). Left-versus right-sided radiation therapy after wide local excision did not increase the risk of all CVD combined, yet an increased ischemic heart disease risk was found (sHR 1.14, 95% CI 1.01-1.28). Analyses including detailed radiation therapy information showed an increased CVD risk for left-sided chest wall irradiation alone, left-sided breast irradiation alone, and internal mammary chain field irradiation, all compared with right-sided breast irradiation alone. Compared with patients not treated with chemotherapy, chemotherapy used >= 1997 (ie, anthracyline-based chemotherapy) increased the risk of CHF (sHR 1.35, 95% CI 1.00-1.83). Conclusion: Radiation therapy regimens used in BC treatment between 1989 and 2005 increased the risk of CVD, and anthracycline-based chemotherapy regimens increased the risk of CHF. (C) 2016 Elsevier Inc. All rights reserved.

Language

English

Source (journal)

International journal of radiation oncology, biology, physics. - Bedford

Publication

Bedford : 2016

ISSN

0360-3016

DOI

10.1016/J.IJROBP.2015.11.040

Volume/pages

94 :5 (2016) , p. 1061-1072