Risk of cancer in adult people diagnosed with infantile autism in childhood: A longitudinal case control study based on hospital discharge diagnoses

• Most of lifetime is spend in adulthood, nevertheless, most research on autism spectrum disorders (ASD) has focused on childhood and adolescence. Accordingly, little is known about the health condition in adults with ASD.
• This study has investigated whether adult people diagnosed with infantile autism (IA) as children may have a higher cancer risk than comparable people from the general population without IA.
• Although cancer diseases occurred at rates similar to the general population, it is important to recognize that adults with IA are at similar risk for these diseases.
• Taken together, there are no published evidence to suggest that there is a high overall concordance between ASD and cancer or between ASD and specific cancers.

Research dealing with adults with autism spectrum disorders (ASD) noticeably lags behind studies of children and young individuals with ASD. The objective of this study is to compare the incidence and types of cancer in a clinical sample of 118 adult people diagnosed with infantile autism (IA) in childhood with 336 sex and age matched controls from the general population. All participants were screened through the nationwide Danish National Hospital Register. The average study interval of both groups was 37.2 years, and mean age at follow-up was 49.6 years. Of the 118 people with IA, 8 (6.8%) were registered with at least one cancer diagnosis against 17 (5.1%) in the comparison group (p = 0.49; OR = 1.4; 95% CI 0.6–3.3). Significant group differences were also lacking with respect to specific cancer types.