Cancer Diagnostics Among People With Intellectual Disability-A Systematic Review

People with intellectual disability (ID) have a markedly lower life expectancy than the general population, with cancer being one of the most common causes of death. This systematic review aims to provide an overview of existing knowledge on cancer diagnostics among people with ID, including cancer screening, routes to cancer diagnosis and cancer stage.

We systematically searched Embase, PubMed, CINAHL and PsycInfo for observational studies on cancer screening, routes to diagnosis, and cancer stage among people with ID published from 2000 onwards. Study selection and quality assessment were conducted independently by two authors.

Twenty-five register-based studies met the inclusion criteria. Sixteen consistently reported lower cancer screening participation among people with ID. Three studies found that people with ID were less likely to be diagnosed through standardized, fast-track pathways and more likely to be diagnosed following emergency hospital contacts. Across nine studies, people with ID were more often diagnosed at advanced or unknown cancer stage than those without ID.

People with ID experience substantial inequalities in cancer detection, including lower screening participation, less optimal diagnostic pathways and more frequent diagnosis at advanced or unknown stages. These disparities highlight the need for interventions targeting symptom recognition, diagnostic pathways and healthcare accessibility among people with ID.