Survivors of childhood cancer are living longer, but over time the cardiotoxicity of some chemotherapies and radiation therapy may be taking a toll on their hearts. The American Heart Association published a scientific statement online Sept. 30 in Circulation that reviewed the evidence of cardiotoxicity in childhood survivors and highlighted future directions.

The survival rates for children with cancer continue to increase, and almost a quarter of childhood cancer survivors in the U.S. are beyond 30 years of diagnosis, according to Steven E. Lipshultz, MD, of the University of Miami School of Medicine, and colleagues. Cardiac-specific disease is now the most common noncancer cause of death in these patients.

Certain chemotherapies and radiation therapies have been associated with rhythm abnormalities, left ventricular dysfunction, MI, and hypertension. Latent cardiotoxicity may manifest as heart failure, valvular heart disease, premature coronary artery disease cardiomyopathy and pericarditis. The statement gives an overview of therapies, incidence of cardiovascular outcomes, presentation and progression of disease and strategies for monitoring patients after therapy.

“Long-term cardiovascular monitoring of cancer survivors diagnosed in childhood, adolescence and young adulthood should be aimed at early, preclinical detection, when interventions can be expected to have the greatest benefit; however, evidence-based, comprehensive screening recommendations to standardize and direct follow-up care for cancer survivors have not fully evolved,” wrote the authors.

The statement is targeted toward pediatric oncologists, pediatricians and specialists who treat adolescents and young adults. It is not meant to serve as an evidence-based guideline and avoids giving specific recommendations for care.

“The developing field of cardio-oncology is beginning to provide clinicians with a better model to identify adverse cardiac effects of antineoplastic therapy,” they concluded. “It is crucial that an optimal monitoring regimen is developed based on clinically based evidence.” They added that initiatives are under way to develop guidelines.