Incidence and risk factors of anthracycline-induced cardiotoxicity in long-term survivors of pediatric cancer: A population based cohort study

Population-based data on the incidence of anthracycline-induced cardiotoxicity (AIC) in long-term survivors of childhood cancer is limited but essential in order to identify patients at higher risk. This study will report the incidence and risk factors for AIC in long term survivors of pediatric cancer. A retrospective population-based study was conducted using (i) patient charts (ii) oncology database at the IWK Health Centre, in Halifax, NS. All pediatric oncology patients treated with anthracycline on or before December 2014 and followed in the long-term follow up clinic at the IWK Health Centre were included. Cardiotoxicity was defined as an ejection fraction (EF) < 50% and/or a fractional shortening (FS) < 27% in any echocardiogram or comparable cardiac imaging and/or symptomatic cardiotoxicity. The incidence of AIC was reported. Pearson's Chi-Square and Fisher's exact were used to determine the relationship of cardiac changes to various risk factors. In our study population of 184 patients, we found an incidence of AIC of 5.98%, and found that AIC with long-term complications has a low incidence (2.17%). The mean age at diagnosis for patients with AIC was 5.55 ± 4.97 years. The follow-up time ranged from 5 to 25 years (mean = 9.06). The time from treatment to a cardiac event ranged from 0 to 15 years (mean = 3.82). Our study found that bone marrow transplant (p = 0.025) and cancer diagnosis (p = 0.039) were significantly associated with anthracycline-induced cardiotoxicity. However, when only symptomatic patients were analyzed, only a cumulative dose of anthracycline ≥300 mg/m2 had a significant relationship with AIC (p = 0.017).