Accelerated aging and mortality in long-term survivors of childhood cancer: A report from the St. Jude Lifetime Cohort (SJLIFE).

Abstract

10045 Background: Survivors of childhood cancer have functional limitations and health-related morbidity consistent with an accelerated aging phenotype. We characterized aging using a Deficit Accumulation Index (DAI) which examines the accumulation of multiple aging-related deficits readily available from medical records and self-report. DAI’s are used as surrogates of biologic aging and are validated to predict mortality in adult cancer patients. Methods: We included childhood cancer survivors (N = 3,758, mean age 30 [SD 8], 22 [9] years post diagnosis, 52% male) and community controls (N = 575, mean age 34 [10] 44% male) who completed clinical assessments and questionnaires and who were followed for mortality through December 31st, 2018 (mean follow-up 6.1 [3.1] years). Using the initial SJLIFE clinical assessment, a DAI score was generated as the proportion of deficits out of 44 items related to aging, including chronic conditions (e.g. hearing loss, hypertension), psychosocial and physical function, and activities of daily living. The total score ranged 0 to 1; scores > 0.20 are robust, while moderate and large clinically meaningful differences are 0.02 and 0.06, respectively. Linear regression compared the DAI in survivors and controls with an age*survivor/control interaction and examined treatment associations in survivors. Cox-proportional hazards models estimated risk of death associated with DAI. All models were adjusted for age, sex, and race. Results: Mean [SD] of DAI was 0.17 [0.11] for survivors and 0.10 [0.08] for controls. 32% of survivors had a DAI above the 90th percentile of the control distribution (p < 0.001). After adjustment for covariates, survivors had a statistically and clinically meaningfully higher DAI score than controls (β = 0.072 95%CI 0.062, 0.081; p < 0.001). When plotted against age, the adjusted DAI at the average age of survivors (30 years) was 0.166 (95% CI 0.160,0.171), which corresponded to 60 years of age in controls, suggesting premature aging of 30 years. The mean difference in DAI between survivors and controls increased with age from 0.06 (95% CI 0.04, 0.07) at age 20 to 0.11 (95% CI 0.08, 0.13) at age 60, consistent with an accelerated aging phenotype (p = 0.014). Cranial radiation, abdominal radiation, cyclophosphamide, platinum agents, neurosurgery, and amputation were each associated with a higher DAI (all p≤0.001). Among survivors, a 0.06 increase in DAI was associated with a 41% increased risk of all-cause mortality (HR 1.41 95%CI 1.32, 1.50; p < 0.001). Conclusions: Survivors of childhood cancer experience significant age acceleration that is associated with an increased risk of mortality; longitudinal analyses are underway to validate these findings. Given the ease of estimating a DAI, this may be a feasible method to quickly identify survivors for novel and tailored interventions that can improve health and prevent premature mortality.