Long-term follow-up for cardiovascular disease after chemotherapy and/or radiotherapy for breast cancer in an unselected population

Abstract

Whereas earlier research focused on specific patient groups, this study assessed the risk of cardiovascular disease (CVD) in an unselected population curatively treated for breast cancer (BC), compared with an age-matched random sample of controls. Risks were determined in BC survivors and controls. CVD was divided into three categories: congestive heart failure, vascular cardiac diseases, and "other" cardiac diseases. Hazard ratios (HRs) and 95% confidence intervals (95% CI) adjusted for age, CVD, and CVD risk factors at baseline were determined by Cox regression analyses. All 561 survivors of BC experienced surgery of whom 229 received (neo)adjuvant radiotherapy, 145 received chemotherapy (with or without radiotherapy), and 187 received no adjuvant therapy. During follow-up (median 9; range 5-57 years), CVD occurred in 176/561 (31%) survivors and in 398/1,635 (24%) controls. After radiotherapy, no increased risks of congestive heart failure (HR 0.5; 95% CI 0.2-1.8), vascular cardiac diseases (HR 1.1; 95% CI 0.7-1.7), or other cardiac diseases (HR 1.3; 95% CI 0.8-2.3) were found compared with controls. Similar results were found after chemotherapy for congestive heart failure (HR 1.8; 95% CI 0.6-5.8), vascular cardiac diseases (HR 1.1; 95% CI 0.5-2.3), and other cardiac diseases (HR 1.2; 95% CI 0.3-5.5). In an unselected population of BC survivors, no significant increased risk of CVD after radiotherapy and/or chemotherapy was found compared with controls. However, the HRs after chemotherapy were in-line with previous studies. Future studies should include more detailed information on treatment and more specific outcome measures.