Neurologic morbidity and functional independence in adult survivors of childhood cancer

Objective: To examine associations between neurologic late effects and attainment of independence in adult survivors of childhood cancer treated with central nervous system (CNS)-directed therapies. Methods: A total of 7881 survivors treated with cranial radiation therapy (n = 4051; CRT) and/or intrathecal methotrexate (n = 4193; IT MTX) ([CNS-treated]; median age [range] = 25.5 years [18–48]; time since diagnosis = 17.7 years [6.8–30.2]) and 8039 without CNS-directed therapy reported neurologic conditions including stroke, seizure, neurosensory deficits, focal neurologic dysfunction, and migraines/severe headaches. Functional independence was assessed using latent class analysis with multiple indicators (independent living, assistance with routine and personal care needs, ability to work/attend school, attainment of driver's license, marital/partner status). Multivariable regression models, adjusted for age, sex, race/ethnicity, and chronic health conditions, estimated odds ratios (OR) or relative risks (RR) for associations between neurologic morbidity, functional independence, and emotional distress. Results: Among CNS-treated survivors, three classes of independence were identified: (1) moderately independent, never married, and non-independent living (78.7%); (2) moderately independent, unable to drive (15.6%); and (3) non-independent (5.7%). In contrast to 50% of non-CNS-treated survivors and 60% of siblings, a fourth fully independent class of CNS-treated survivors was not identified. History of stroke (OR = 2.50, 95% CI: 1.70–3.68), seizure (OR = 9.70, 95% CI: 7.37–12.8), neurosensory deficits (OR = 2.67, 95% CI: 2.16–3.31), and focal neurologic dysfunction (OR = 3.05, 95% CI: 2.40–3.88) were associated with non-independence among CNS-treated survivors. Non-independence was associated with emotional distress symptoms. Interpretation: CNS-treated survivors do not attain full independence comparable to non-CNS-treated survivors or siblings. Interventions to promote independence may be beneficial for survivors with treatment-related neurological sequalae.