AHA outlines CV toxicity management in young patients undergoing cancer treatment

Investigators with the American Heart Association recently published a comprehensive summary outlining all aspects of cardiotoxicity associated with cancer therapy in children, adolescents and young adults. The statement includes information on short-, medium- and potential long-term CV effects of not just antineoplastic agents, but combination therapies.

More comprehensive research is required in several areas, according to the authors. One of those areas is the detection and monitoring of late cardiotoxicity. Another is the modalities for diagnosing and monitoring left ventricular function. Echocardiography is currently the standard, but novel echocardiographic techniques such as myocardial velocity and deformation warrant further investigation, as does cardiac MRI.

Indices of LV systolic function including fractional shortening and ejection fraction may not be sufficient for assessing LV diastolic and systolic dysfunction, according to the authors. They added that improved screening tools may result from broader epidemiological study.

Toxicities associated with pediatric cancer treatments such as anthracyclines, chest or gonadal radiation and high-dose alkylating agents such as cyclophosphamide, ifosfamide, cisplatin and mitomycin may affect endocrine, reproductive, musculoskeletal or neurological function and cause obesity, diabetes, CVD or hypertension. Survivors may experience MI, valvular disease, conduction abnormalities, pericarditis or cardiomyopathy, according to the authors.

Regarding specific therapies, the investigators cited evidence that dexrazoxane administered with doxorubicin may reduce cardiotoxicity. As for causative agents, taxanes/paclitaxel may lead to bradycardia; anthracyclines such as doxorubicin may be associated with arrhythmias and QT prolongation; antimetabolites/5-fluorouracil may cause myocardial ischemia; anthracyclines such as doxorubicin, tyrosine kinase inhibitors such as imatinib (Gleevec, Novartis) or sunitinib (Sutent, CPPI CV), alkylating agents such as cyclophosphamide or ifosfamide, or cisplatin may be associated with LV dysfunction or congestive HF.

Conventional HF therapy may not be appropriate in childhood cancer survivors experiencing cardiac dysfunction, according to findings in the statement. Further investigation is required to determine appropriate strategies for monitoring CV outcomes in this patient population, and how it may affect HF incidence. More randomized trials with longer follow-up, along with more comprehensive clinical registries, may provide answers to these questions.

The investigators noted that CV-associated diseases cause considerable morbidity and mortality among the hundreds of thousands of childhood cancer survivors in the United States each year. Death and stroke risk in this population may be eight to 10 times higher than in the general population.

The authors said primary prevention is critical to reducing poor CV outcomes in this population.

For more information, visit:

http://circ.ahajournals.org/content/128/17/1927.full.