Impact of Cancer Therapy-Related Exposures on Late Mortality in Childhood Cancer Survivors.

Survival of children and adolescents diagnosed with cancer has improved dramatically in recent decades, but the substantial burden of late morbidity and mortality (i.e., more than 5 years after cancer diagnosis) associated with pediatric cancer treatments is increasingly being recognized. Progression or recurrence of the initial cancer is a primary cause of death in the initial postdiagnosis period, but as survivors age, there is a dramatic shift in the cause-specific mortality profile. By 15 years postdiagnosis, the death rate attributable to health-related causes other than recurrence or external causes (e.g., accidents, suicide, assault) exceeds that due to primary disease, and by 30 years, these causes account for the largest proportion of cumulative mortality. The two most prominent causes of treatment-related mortality in childhood cancer survivors are subsequent malignant neoplasms and cardiovascular problems, the incidence of which can be largely attributed to the long-term toxicities of radiation and chemotherapy exposures. These late effects of treatment are likely to increase in importance as survivors continue to age, inspiring continued research to better understand their etiology and to inform early detection or prevention efforts.