Childhood cancer survivors are at an increased risk for experiencing a cardiac event early in life, particularly those who have undergone potentially cardiotoxic treatment, study results suggest.
The risk for these events, the most common of which was congestive heart failure, may be as high as 1 in 8.
Previous research has established that anthracyclines and cardiac irradiation are linked to asymptomatic cardiac events in survivors of cancer. However, data related to the occurrence of symptomatic cardiac events in survivors of childhood cancers are sparse, according to the researchers.
Stella M. Davies
The researchers examined cardiac events in a cohort of 1,362 childhood cancer survivors who had survived 5 years or longer. Patients were diagnosed between 1966 and 1996 and were evaluated for grade-3 or higher congestive heart failure, cardiac ischemia, valvular disease, arrhythmia and/or pericarditis.
Of the survivors examined, more than half received treatments that could have potentially been cardiotoxic, including anthracyclines (33.6%), cardiac irradiation (11.6%) or both (7.9%). The median time since cancer diagnosis was 22.2 years.
During time since diagnosis, 50 cardiac events had occurred in 42 survivors after a median follow-up of 18.6 years. Median age at the time of the event was 27.1 years. All but two of the survivors who had a cardiac event had received potentially cardiotoxic therapy. Congestive heart failure was the most commonly occurring cardiac event.
The 30-year cause-specific cumulative incidence of cardiac events was significantly increased after treatment with anthracyclines, cardiac irradiation, or both (see chart).
“Although the frequency of severe cardiac complications is alarming, all studies that examine truly late outcomes (beyond 20 years) suffer from the problem that they observe and report outcomes of therapies that have since been modified and in some instances are no longer used,” Stella M. Davies, MBBS, PhD, MRCP, director of bone marrow transplantation and immune deficiency at Cincinnati Children’s Hospital Medical Center, wrote in an accompanying editorial.
“As targeted therapies and small molecules with specific and not generally cytotoxic modes of action emerge, we can hope for a reduction in late adverse effects 40 or 50 years from now,” Davies added. “However, because the majority of children diagnosed with cancer in 2012 will achieve long-term survival with relatively modest refinements of the therapies used in the 1970s, continued focus on surveillance and management of late effects, and education of internists and insurers, remain at the heart of the matter. “