Increased Heart Disease Risk Among Childhood Cancer Survivors Highlights Need To Focus On Healthy Lifestyles

Photo of Sarah de Ferranti, M.D., M.P.H.Sarah de Ferranti, M.D., M.P.H., Chief, Division of Cardiology Outpatient Services and Director, Preventive Cardiology, Boston Children’s Hospital; Associate Professor of Pediatrics, Harvard Medical School

Childhood cancer survivors face an increased risk of heart disease compared to people without cancer, according to a study published today in the American Heart Association journal Circulation.

The finding is based on a comparison of nearly 7,300 five-year cancer survivors with 36,200 people free of cancer matched based on age, sex and postal code. The survivors, who were enrolled in a pediatric cancer registry in Ontario, Canada were diagnosed before age 18 and treated in a pediatric cancer care center between 1987-2010.

Researchers reviewed the risk of several heart diseases — heart failure, arrhythmia, pericardial disease, valvular disease and coronary artery disease — in two cohorts, cancer survivors and individuals without childhood cancer, after a median follow-up of 10 years. They found:
  • Almost 3% of cancer survivors experienced at least one cardiac event, even at relatively young ages, compared to less than 1% of those without cancer.
  • Notably, survivors were at a tenfold higher risk for developing heart failure.
  • Among survivors, several cancer-related factors were associated with higher risks of CVD including relapse or subsequent cancer, and exposure to a certain level of anthracycline chemotherapy.
  • Survivors diagnosed with hypertension were three times more likely to develop heart failure compared to survivors without hypertension.
  • Survivors with diabetes were three times more likely to develop CVD and over four times more likely to develop heart failure compared to survivors without diabetes.

There may also be a relationship between radiation therapy to the chest and increased cardiac risk, but researchers noted that because radiation-associated CVD can take 15 or more years to present, the duration of patient follow-up was insufficient to say definitively whether such a relationship exists or not.

Opportunity to highlight healthy lifestyle behaviors

Cancer therapies can also increase the risk of diabetes, hypertension and dyslipidemia, conditions that increase CVD risk, as this study and previous research indicate. Targeting modifiable risk factors — such as smoking, physical activity and dietary and alcohol intake — could be an important way to reduce the chance of diabetes and hypertension.

Heart disease begins in childhood, even among people who haven’t had childhood cancer, so practicing healthy habits at an early age can help prevent problems later in life. This study wasn’t able to measure participants’ lifestyle habits, but future research could determine if such habits during or after cancer treatment can affect cancer survivors’ CVD risk. Additionally, surveillance for all types of CVD among childhood cancer survivors could help better predict rates of future CVD, track the impact of new cancer treatments on CVD and provide data that supports targeted interventions to promote healthy lifestyles.