Childhood Hodgkin Lymphoma Survivors Have High Burden of Cardiovascular Conditions

Survivors of childhood Hodgkin lymphoma had more than twice the number of chronic cardiovascular health conditions and fivefold the number of severe cardiovascular conditions at age 50 vs a group of controls, according to the results of a study published in Lancet Oncology.

“We applied the cumulative burden metric to quantify the added magnitude and trajectory of total cardiovascular morbidity in survivors of Hodgkin lymphoma compared with a control population,” wrote Nickhill Bhakta, MD, of St Jude Children’s Research Hospital in Memphis, and colleagues. “To our knowledge, our approach represents the first application of this metric to study both recurrent and multiple events in a setting where death represents a substantial competing risk and different pathophysiological processes occur.”

The analysis included patients who had been treated or followed at St Jude who reached the age of 18 and were at least 10 years post-diagnosis with primary Hodgkin lymphoma. The patients were taken from two ongoing cohort studies: the St Jude Lifetime Cohort Study (SJLIFE) and the St Jude Long-Term Follow-up Study (SJLTFU). Outcomes among these patients were compared with those of SJLIFE community control participants. All SJLIFE participants were assessed for 22 chronic cardiovascular health conditions.

The researchers identified 670 survivors, of whom 348 were assessed in SJLIFE and 322 were not. At age 50 years, the cumulative incidence of survivors experiencing at least one grade 3–5 cardiovascular condition was 45.5% compared with 15.7% in the controls. There was no difference in the cumulative incidence of grade 1–5 cardiovascular health conditions.

In contrast to the cumulative incidence, survivors experienced a cumulative burden of 430.6 grade 1–5 and 100.8 grade 3–5 cardiovascular conditions per 100 survivors, nearly double that of the controls (227.4 grade 1–5 and 17.0 grade 3–5 conditions per 100 individuals).

“Although the average annual increase of grade 1–5 conditions is higher in all SJLIFE-eligible survivors than in community controls between the ages of 30 and 55 years, by age 45 years, the average annual increase of grade 1–2 conditions in community controls equals and surpasses that of the survivors,” the researchers wrote. “However, for grade 3–5 conditions, the rate of increase in cumulative burden among survivors remains greater than that of community controls over the entire range of attained age of the cohort.”

The major contributors to the grade 3–5 burden among survivors were myocardial infarction and structural heart defects. In addition, a cardiac radiation dose of 35 Gy or higher was associated with an increased number of grade 3–5 cardiovascular burden; however, increased anthracycline dose was not.

In a comment published with the study, editorialists wrote, “Bhakta and colleagues propose a novel method for quantifying the total cardiovascular burden of young survivors of Hodgkin lymphoma treated in the past by considering all the cardiovascular conditions observed so far in the patient’s lifetime. Their approach might be relevant not just for this example but also for many other cancer diagnoses and late side effects. Furthermore, assessment of the continuing cumulative burden of treatment-related morbidity is relevant not only from a clinical viewpoint but also from a health economics perspective.”