Yield of screening echocardiograms during pediatric follow-up in survivors treated with anthracyclines and cardiotoxic radiation.

BACKGROUND: Guidelines published by the Children's Oncology Group recommend screening echocardiograms for childhood cancer survivors exposed to anthracyclines and/or cardiotoxic radiation. This study aims to assess risk factors for cardiac late effects while evaluating the overall yield of screening echocardiograms.

PROCEDURE: Demographics, exposures, and echocardiogram results were abstracted from the medical records of survivors diagnosed at ≤ 21 years old and ≥ 2 years off therapy who were exposed to anthracyclines and/or potentially cardiotoxic radiotherapy. Descriptive statistics and logistic regressions were performed and the yield of screening echocardiograms was calculated.

RESULTS: Of 853 patients, 1,728 screening echocardiograms were performed, and 37 patients had an abnormal echocardiogram (overall yield 2.1%). Yields were only somewhat higher in more frequently screened patients. Risk factors for an abnormal result included anthracycline dose of ≥300 mg/m2 (adjusted odds ratio [aOR] 3.1; 95% confidence interval [CI]: 1.3-7.2; P < 0.01) with a synergist relationship in patients who also received radiation doses ≥30 Gy (aOR 7.0; 95% CI: 1.6-31.9; P = 0.01), as well as autologous bone marrow transplant (OR 3.3; 95% CI: 1.3-8.5; P = 0.01). Sex, race, age at diagnosis, and cyclophosphamide exposure were not statistically significant risk factors, and no patient receiving <100 mg/m2 anthracycline dose without concomitant radiation had an abnormal echocardiogram.

CONCLUSIONS: Dose-dependent and synergist anthracycline and cardiotoxic radiotherapy risks for developing cardiomyopathy were confirmed. However, previously identified risk factors including female sex, black race, and early age at diagnosis were not replicated in this cohort. The yields showed weak correlation across frequency categories. Echocardiographic screening recommendations for low-risk pediatric patients may warrant re-evaluation.