Adverse mental health outcomes in a population-based cohort of survivors of childhood cancer

Background — The elevated risk for physical late effects in childhood cancer survivors (CCS) is well documented, but their risk for mental health problems is less well described.

Methods — We assembled a cohort of all five-year CCS diagnosed before age 18 years and treated in an Ontario pediatric cancer center between 1987-2008. Patients were matched to population controls, and linked to health administration databases. We calculated rates of mental healthcare visits (family physician, psychiatrist, emergency department [ED], hospitalization) and risk for a severe mental health event (ED, hospitalization, suicide). Outcomes were compared using recurrent event and survival analyses.

Results — Compared to 20,269 controls, 4,117 CCS had a higher rate of mental health visits (Adjusted relative rate [RR] 1.34, 95% CI 1.12-1.52). Higher rates were associated with female gender (RR 1.39, CI 1.10-1.75; p=0.006) and age 15-17.9 years at diagnosis (compared to age 0-4 years, RR 1.81, CI 1.17-2.80 p=0.008). Cancer type, treatment intensity, and treatments targeting the CNS were not significant predictors. Survivors were at increased risk of a severe event compared to controls (adjusted hazard ratio 1.13, 95% CI 1.00-1.28; p=0.045). CCS diagnosed with cancer at ≤4 years were at greatest risk; 16.3% (95% CI 13.2-19.8%) experienced a severe event by age 28.

Conclusion — CCS experience higher rates of mental health visits and a greater risk for a severe event than the general population. Survivors of adolescent cancer have a higher rate of mental health visits overall, while survivors of cancer prior to age 4 have a markedly elevated risk of severe events.