Accelerated Aging in Survivors of Childhood Cancer-Early Onset and Excess Risk of Chronic Conditions.

Importance: The lifetime risk of aging-related diseases among survivors of childhood cancer, accelerated by cancer treatment exposures, is unknown. Understanding this risk can provide a more comprehensive assessment of long-term health across the lifespan of survivors and guide adult care. Objective: To estimate the lifetime risks of 8 treatment-related cancers and cardiovascular conditions among childhood cancer survivors and compare them with the general population. Design, Setting, Participants: Using data from the Childhood Cancer Survivor Study and national databases, this simulation modeling study projected long-term outcomes for 5-year survivors diagnosed between 1970 and 1999 based on treatment exposures and age-related risks. The general population comparator was simulated using age-, sex-, and calendar year-matched individuals who faced only age-related risks. Exposures: Treatment era (1970s, 1980s, 1990s), original cancer diagnosis, radiation treatment for primary diagnosis (any, none). Main Outcomes and Measures: Estimated lifetime risks of 8 health conditions (breast cancer, colorectal cancer, glial tumors, sarcomas, heart failure, coronary heart disease/myocardial infarction, stroke, and valvular disease). Risks were projected and compared with the general population, stratified by radiation exposure. Results: In the general population, 20% developed at least 1 health condition by age 65.0 years; in 5-year survivors this threshold was reached at age 47.3 years, representing a 17.7-year (95% uncertainty interval [UI], 14.0-21.0) acceleration in disease onset. By age 65 years, 55% of survivors were projected to develop at least 1 condition, indicating a 2.7-fold (95% UI, 2.2-3.5) higher relative risk and 34.2% (95% UI, 28.3-42.5) absolute excess risk compared with the general population. Risks were higher among those treated with radiation therapy for childhood cancer (22.0 years earlier onset [95% UI, 18.0-25.0]; 37.3% excess risk [95% UI, 31.6%-44.7%]) but still elevated for those without radiation exposure (13.5 years earlier onset [95% UI, 10.0-16.0]; 31.0% excess risk [95% UI, 23.9%-40.3%]). Reaching middle age was still associated with increased health risks. Compared with the general population, survivors who reached age 40 years had a 6.2-fold higher risk (95% UI, 4.8-9.4) of developing a new condition within 10 years. Conclusions and Relevance: This study found that survivors of childhood cancer experience accelerated onset of aging-related diseases, regardless of prior radiation exposure. These findings underscore the importance of prioritizing cancer and cardiovascular disease prevention among survivors decades earlier than for the general population.