Purpose: Cardiac disease is second only to neoplastic disease as a cause of death after treatment for Hodgkin's disease. This study evaluates the risks of cardiac disease following treatment of Hodgkin's disease during childhood and adolescence.
Patients and methods: We reviewed records of 635 patients treated for Hodgkin's disease before 21 years of age at Stanford University between 1961 and 1991. Mean age was 15.4 years; mean follow-up duration was 10.3 years, representing 6,564 person-years of observation. Relative risks (RRs) of death from cardiac diseases were calculated by comparison with age-, sex-, and race-matched general population rates from United States decennial life-tables.
Results: Twelve patients have died of cardiac disease (RR, 29.6; 95% confidence interval [CI], 16.0 to 49.3), including seven deaths from acute myocardial infarction ([AMI] RR, 41.5; 95% CI, 18.1 to 82.1), three from valvular heart disease, and two from radiation pericarditis/pancarditis. Thus far, the risk of AMI death was comparable after radiation alone (RO) or after chemotherapy and radiation (CM) (RO-AMI RR, 52.2; 95% CI, 21.1 to 108.7; CM-AMI RR, 21.1; 95% CI, 0.0 to 104.4; P = .6). The risk for other cardiac death (CD) tended to be higher after combined treatment (RO-non-AMI RR, 7.4; 95% CI, 0.0 to 36.5; CM-non-AMI RR, 45.8; 95% CI, 14.4 to 110.6; P = .1). Deaths occurred 3 to 22 years after patients received 42 to 45 Gy to the mediastinum between 9 and 20 years of age. There have been no deaths among patients treated to lower mediastinal radiation doses or without mediastinal radiation. There are no clear trends in the latency of risk. One hundred six nonfatal abnormalities have also been diagnosed.
Conclusion: Mediastinal radiation of 40 to 45 Gy increases the risk of death from coronary artery and other cardiac diseases. The risk increases within 5 years of irradiation. These observations support combined-modality, low-dose irradiation regimens in children and adolescents and suggest the need for careful cardiac screening of treated patients.