Childhood Cancer Survivors at Elevated Risk of Heart Disease

August 27, 2019
Survivors of childhood cancer have a higher risk of developing a range of heart disease due to cancer therapy, according to a study published in Circulation. Most studies of childhood cancer survivors have focused only on heart failure related to anthracyclines. The current study used data from Ontario’s healthcare system to investigate the full spectrum of heart disease subtypes in close to 7,300 childhood cancer survivors compared with more than 36,000 people of the same age, gender, and postal code without cancer. Heart disease studied included coronary artery disease, arrhythmias, valve abnormalities, cardiomyopathy, heart failure and pericardial disease. Results showed that, even at relatively young ages, childhood cancer survivors have up to a 3-fold increase for any cardiac event and up to a 10-fold increased risk for heart failure compared with their cancer-free peers. In addition, survivors exposed to higher doses of anthracycline chemotherapy, as well as those diagnosed with diabetes, hypertension or both, are significantly more likely to experience heart disease as adults. “While anthracycline chemotherapy may induce heart disease, many patients require this cancer treatment to survive,” said Paul Nathan, MD, The Hospital for Sick Children (SickKids), Toronto, Ontario. “Doctors should address heart disease risk factors, such as diabetes and hypertension, that can be modified.” Childhood cancer survivors appear to have a higher likelihood of metabolic conditions such as diabetes, hypertension, and unhealthy levels of lipids. These modifiable risk factors appear to interact with chemotherapy or radiation that may be toxic to the heart, prematurely age the heart, and accelerate the development of heart disease. “The close connections between lifestyle, metabolic disorders, and cardiac disease warrant careful follow-up and monitoring of the childhood cancer survivor population,” said Dr. Nathan. The researchers used the Pediatric Oncology Group of Ontario Networked Information System (POGONIS), a provincial paediatric cancer registry, to identify 5-year cancer survivors who were diagnosed before age 18 and treated in a paediatric cancer centre between 1987 and 2010. Each childhood cancer survivor was matched to 5 cancer-free peers. During an average of 10 years of follow-up, nearly 3% of childhood cancer survivors experienced ≥1 cardiac events. Of the controls without cancer, less than 1% experienced a cardiac event. The researchers were unable to assess lifestyle factors, but a more comprehensive understanding of modifiable factors and their impact on cardiovascular disease among childhood cancer survivors could be gained through future work involving the use of data from multiple sources. Reference: SOURCE: American Heart Association