A Model-Based Estimate of Cumulative Excess Mortality in Survivors of Childhood Cancer

Background: Although childhood cancer survival rates have dramatically increased, survivors face elevated risk for life-threatening late effects, including secondary cancer. Objective: To estimate the cumulative effect of disease-and treatment-related mortality risks on survivor life expectancy. Design: State-transition model to simulate the lifetime clinical course of childhood cancer survivors. Setting: Childhood Cancer Survivor Study. Patients: Five-year survivors of childhood cancer. Measurements: Probabilities of risk for death from the original cancer diagnosis, excess mortality from subsequent cancer and cardiac, pulmonary, external, and other complications, and background mortality (age-specific mortality rates for the general population) were estimated over the lifetime of survivors of childhood cancer. Results: For a cohort of 5-year survivors aged 15 years who received a diagnosis of cancer at age 10 years, the average lifetime probability was 0.10 for late-recurrence mortality; 0.15 for treatment-related subsequent cancer and death from cardiac, pulmonary, and external causes; and 0.05 for death from other excess risks. Life expectancy for the cohort of persons aged 15 years was 50.6 years, a loss of 10.4 years (17.1%) compared with the general population. Reduction in life expectancy varied by diagnosis, ranging from 4.0 years (6.0%) for kidney tumor survivors to more than 17.8 years (>= 28.0%) for brain and bone tumor survivors, and was sensitive to late-recurrence mortality risk and duration of excess mortality risk. Limitation: Estimates are based on data for survivors who received treatment 20 to 40 years ago; patients who received treatment more recently may have more favorable outcomes. Conclusion: Childhood cancer survivors face considerable mortality during adulthood, with excess risks reducing life expectancy by as much as 28%. Monitoring the health of current survivors and carefully evaluating therapies with known late toxicities in patients with newly diagnosed cancer are needed.