The Burden of Cardiovascular Disease in Pediatric Leukemia Survivors

Pediatric Hodgkin lymphoma survivors are more than twice as likely to develop cardiovascular issues as an adult than those who did not have a history of pediatric cancer, a study published in The Lancet Oncology journal found.

In the study, researchers used a cumulative burden measure instead of the currently used statistical methods, which counts health conditions once at diagnosis, to help better examine the distribution and magnitude of chronic disease in survivors of childhood cancer.

The cumulative burden allows researchers to track an individual’s multiple, recurring treatment-related health conditions. It could help aid researchers in refining health screening guidelines for survivors, and to design clinical trials that maintain high cure rates that also reduce the late effects of treatment.

“With cure rates for pediatric cancer at historic highs, the question becomes what is the legacy of that cure?” said first and corresponding study author Nickhill Bhakta, MD. “We are doing a better job of keeping patients alive, but are we doing a better job at addressing the chronic diseases that are sometimes the price of that cure. Cumulative burden is a new tool for studying for chronic illness in childhood cancer survivors or any patient population with significant morbidity, such as diabetes or HIV/AIDS.”

During the study, researchers calculated the cumulative burden of cardiovascular disease in 670 pediatric Hodgkin lymphoma survivors based on a detailed health analysis of 348 patients enrolled in the St Jude Lifetime Cohort Study (St. Jude LIFE). The survivors were a minimum of 18-years-old, and survived at least 10 years after being diagnosed with cancer.

First the St Jude LIFE participants were assessed for 22 chronic cardiovascular conditions that included, arrhythmias, heart attacks, hypertension, and structural heart defects. The assessments and other clinical findings were then used to calculate the cumulative burden by tracking the incidence and severity of cardiovascular disease.

The cumulative burden was also calculated for a comparison group of 272 St Jude LIFE community volunteers who had no history of childhood cancer,and were similar in age and gender to the group of cancer survivors.

The results of the analysis showed that the cumulative burden of cardiovascular disease was greater among survivors at 30- and 50-years-old, compared with the comparison group, which also included severe and life threatening conditions. Additionally, the cumulative burden of the most serious heart conditions, including heart attacks, was similar for 30-year-old survivors and 50-year-old community volunteers.

Although there were similarities found among both of the groups with severe, chronic heart conditions that became more common with age. The serious problems seemed to accumulate more rapidly in the group of survivors.

“Survivors tended to have more severe disease across the lifespan and likely need an individualized screening and treatment plan,” Bhakta said.

Authors noted that the findings highlighted some potential trade-offs that should be considered when designing future clinical trials, such as: reducing the dose of anthracyclines, which will reduce the rate, but not the severity of cardiovascular disease in pediatric and young adult Hodgkin lymphoma survivors; or lowering the heart radiation dose, which will not significantly lower the rate of cardiovascular disease but will reduce the severity.

“Cumulative burden provides us with a global view of tradeoffs between different treatment late effects that must be considered when designing new interventions,” Bhakta said.