Predicting ischemic heart disease and stroke in survivors of childhood cancer

This study investigated the individual risk of ischemic heart disease and stroke through age 50 in 5-year survivors of childhood cancer. The authors concluded that these conditions can be reasonably predicted using information available after childhood cancer therapy.

For the 400,000 childhood cancer survivors in the U.S., heart disease is the top non-cancer contributor to early death. In recent years, radiation exposure to the heart, brain, or neck have been identified as risk factors for these conditions after cancer therapy. Cancer treatment itself can also cause side effects that later lead to poorer heart health. For example, neuropathy (tingling or numbness) can lead to decreased physical activity, obesity, and eventual high blood pressure or diabetes.

Childhood cancer survivors have a 10 times greater risk of heart disease and stroke compared to healthy siblings. For this high-risk population, models that predict the rates of these conditions after cancer treatment exposure may be useful, especially as these patients grow older.

This study analyzed data from 13,060 participants who participated in the Childhood Cancer Survival Study (1970 – 1986) and survived at least 5 years after diagnosis. Data was collected from medical records and self-reported questionnaires. Patients were divided into risk groups (low, moderate, and high). Outcomes were limited to those that happened by age 50. The average follow-up was 19 years.

At follow-up by age 50, there were 265 cases of ischemic heart disease and 295 cases of stroke. The cumulative incidence (CIR; number of new cases per person by age 50) rates were 7.7% (ischemic heart disease) and 6.3% (stroke).

Overall, the predicted CIRs for both conditions were less than 5% (low risk patients) and 20% (high risk patients). For ischemic heart disease, the predicted CIRs were 2.3% (low risk) and 11.9% (moderate risk). For stroke, the CIRs were 2.4% (low risk) and 6.9% (moderate risk). For high-risk patients, the predicted CIR was 19.9% for both ischemic heart disease and stroke.

The authors concluded that ischemic heart disease and stroke can be reasonably predicted for childhood cancer survivors, especially those who may have cardiovascular risk factors. Current data suggests that these survivors may still be at risk after treatment, perhaps more so than the general population.

A key limitation of this study is that ischemic heart disease and stroke cannot be predicted 5 years after diagnosis. This is because most childhood survivors are still young, and these conditions take decades to develop. More follow-up is needed to determine whether childhood cancer treatments influence survival as young survivors get older.

If you are a childhood cancer survivor, talk to your doctor about your risk of developing heart disease or stroke.