Cardiotoxicity Among Childhood Cancer Survivors Decreasing Over Time

Submitted by admin5 on Tue, 01/24/2017 - 20:56

Initiatives to reduce cardiotoxicity among childhood patients with cancer treated more recently have had a measurable impact over time, according to research published in Circulation.
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Previous research has shown an increased risk of cardiac morbidity and mortality among childhood cancer survivors. Yet, the long-term risks of cardiac-specific mortality and the relative risk among those childhood patients more recently diagnosed has not been extensively analyzed, prompting a need for further studies.

Researchers led by Michael M Hawkins, MSc, BSc, Centre for Childhood Cancer Survivor Studies, University of Birmingham (UK), investigated the risk of long-term cardiac-specific mortality among childhood cancer survivors by utilizing the British Childhood Cancer Survivor Study, the largest population-based cohort in existence to assess late cardiac mortality. The cohort consists of 34,489 5-year survivors of childhood cancer diagnosed from 1940-2006 and contains follow-up data from as recently as 2014. Researchers used standardized mortality ratios and absolute excess risks to measure cardiac-specific mortality excess risk as well as multivariable Poisson regression models and likelihood-ratio tests to evaluate effect of risk factors and trends over time.

Results of the study showed cardiac-specific mortality among 5-year survivors of childhood cancer has remained increased for survivors aged > 50 years. However, risk was greatest in those patients diagnosed from 1980-1989. Childhood survivors diagnosed between 1980-1989 had 28.9-times the excess number of deaths observed than those survivors diagnosed either before 1970 or from 1990 onwards. Leading causes of cardiac-specific mortality included primary neoplasms (31%), cardiac disease (22%), and other circulatory conditions (15%).

Researchers believe the higher rate of cardiac-specific mortality for childhood survivors from 1980-1989 reflects the effects of “anthracycline chemotherapy, which has been shown to increase the risk of dilated cardiomyopathy and congestive heart failure.” The fact that childhood survivors diagnosed between 1990 and 2006 are no more likely to die of cardiac causes than those diagnosed before 1970 suggests the success of initiatives to reduce cardiotoxicity such as “alternative drugs, lowering cumulative doses, and improved monitoring and intervention.”

Researchers concluded that the specific causes of mortality shown in their study provide a clear focus for preventative interventions for the future.