Late psychiatric morbidity in survivors of cancer at a young age: A nationwide registry-based study

Childhood cancer survivors have been shown to be prone to psychosocial adverse outcomes. Data on young adults and their psychiatric late effects are still scarce. In a nationwide, registry-based study, we explored the risk (HR) of new psychiatric diagnoses in 5-year survivors of childhood and young adulthood (YA) cancer (n = 13,860) compared with a sibling cohort (n = 43,392). Hazard ratios (HRs) were calculated using Cox regression models. Patients and siblings were identified from the Finnish Cancer Registry and Central Population Registry, respectively. Outcome diagnoses were retrieved from the national hospital discharge register. The risk of organic memory/brain disorders was significantly increased in both childhood (HR 4.9; 95%CI 2.7-8.9) and YA (HR 2.1; 95%CI 1.4-3.1) cancer survivors compared with siblings. Mood disorders were also more common in childhood (HR 1.3; 95%CI 1.1-1.7) and YA survivors (1.3; 95%CI 1.1-1.5) than in siblings. Radiotherapy did not explain the differences. Female childhood cancer survivors had significantly increased HRs for mood disorders, psychotic disorders, neurotic/anxiety disorders, somatization/eating disorders and personality disorders. In survivors of YA cancers, females had significantly increased HR for neurotic/anxiety disorders, and the difference between female survivors and siblings was significantly (p < 0.05) higher than that between male survivors and male siblings. The effect of treatment era was also analyzed, and the risk of organic memory and brain disorders in childhood cancer survivors did not diminish over time. Despite the trend of decreased use of cranial irradiation in children, the risk of organic memory/brain disorders was elevated, even during the most recent era. Thus, additional research on chemotherapy-only protocols and their impact on mental health, is warranted.