As Dr. Helena J. van der Pal told Reuters Health by email, “Long-term survivors of childhood cancer have a high treatment-related risk of developing clinical heart disease, especially congestive heart failure. For survivors treated with both anthracyclines and radiotherapy involving the heart region, the risks are the highest; one in eight had severe heart disease 30 years later.”
Dr. van der Pal, with the Academic Medical Center, Amsterdam and colleagues came to this conclusion after examining data on a hospital-based cohort of 1362 5-year childhood cancer survivors diagnosed between 1966 and 1996.
Overall, there were 50 cardiac events, including 27 cases of congestive heart failure, in 42 survivors. These occurred at a median of 18.6 years after cancer diagnosis and at a median age of 27.1 years.
Compared to other treatments, the 30-year cause-specific cumulative incidence of these events was significantly increased after combination treatment with anthracyclines and cardiac irradiation (12.6%). Corresponding rates were 7.9% after anthracyclines and 4.0% after cardiac irradiation.
Further analysis showed that the anthracycline dose, the cardiac radiation dose, and the combination of these treatments as well as congenital heart disease were significantly associated with developing a symptomatic cardiac event. There was an exponential relationship between the cumulative anthracycline dose and irradiation dose and the risk of such an event.
Although suggested in other studies, the team found no evidence that other chemotherapy or being female were risk factors.
“The most important take home messages for clinicians,” concluded Dr. van der Pal, “are that survivors of childhood cancer need continued risk-based (based on cancer treatment received) follow-up long after cancer treatment. Survivors who received either anthracyclines or radiotherapy involving the heart region should receive cardiac follow-up by assessing heart function in order to detect and treat deterioration of cardiac function early.”