Long-term cardiovascular disease risk after anthracycline and trastuzumab treatments in U.S. breast cancer survivors.

Abstract

Although breast cancer survivors are at risk for cardiovascular disease (CVD) from treatment late effects, evidence to inform long-term and age-specific cardiovascular surveillance recommendations is lacking. We conducted a retrospective cohort study of 10,211 women diagnosed with first primary unilateral breast cancer in Kaiser Permanente Washington or Colorado (aged 20+, survived ≥1 year). We estimated multivariable adjusted hazard ratios (aHR) for associations between initial chemotherapy regimen type (anthracycline and/or trastuzumab, other chemotherapies, no chemotherapy [reference]) and CVD risk, adjusted for patient characteristics, other treatments, and CVD risk factors. Cumulative incidence was calculated considering competing events. After 5.79 median years, 14.67% of women developed CVD (cardiomyopathy/heart failure (CM/HF), ischemic heart disease (IHD), stroke). Women treated with anthracyclines and/or trastuzumab had a higher risk of CVD compared with no chemotherapy (aHR=1.53,95%CI=1.31-1.79), persisting 5+years post-diagnosis (aHR5-<10 years=1.85,95%CI=1.44-2.39;aHR10+ years=1.83,95%CI=1.34-2.49). CM/HF risks were elevated among women treated with anthracyclines and/or trastuzumab compared with no chemotherapy, especially for ages<65 (aHR20-54years=2.97,95%CI=1.72-5.12;aHR55-64years=2.21,95%CI=1.52-3.21), differing for older women (aHR65+years=1.32,95%CI=0.97-1.78), and 5+years post-diagnosis (aHR5-<10years=1.89,95%CI=1.35-2.64;aHR10+years=2.21,95%CI=1.52-3.20). Anthracyclines and/or trastuzumab receipt was associated with increased IHD risks after 5+years (aHR5-<10years=1.51,95%CI=1.06-2.14;aHR10+years=1.86,95%CI=1.18-2.93) with no clear age effects, and stroke risk (aHR=1.33,95%CI=1.05-1.69) which did not vary by time or age. There was some evidence of long-term CM/HF and IHD risks with other chemotherapies. Among women aged<65 treated with anthracyclines and/or trastuzumab, up to 16% developed CVD by 10-years (20-54=6.91%;55-64=16.00%), driven by CM/HF (20-54=3.90%;55-64=9.78%). We found increased long-term risks of CM/HF and IHD among breast cancer survivors treated with anthracyclines and/or trastuzumab, and increased CM/HF risk among women aged<65.