Background: People with intellectual disabilities have a unique cancer profile, with their needs often unrecognised and unmet. To address this, the CANDID study will explore cancer incidence, route to diagnosis, treatment patterns, and outcomes for adults with intellectual disabilities in Ireland. By comparing this to those without intellectual disabilities it will generate evidence to identify inequalities and inequities and help ensure people with intellectual disabilities receive equitable access to cancer care and inform national policies. Methods: The National Cancer Registry of Ireland dataset will be linked to NASS data, using a validated algorithm to identify people with intellectual disabilities who have been diagnosed with cancer. Cancer incidence rates and trends will be estimated for adults with intellectual disabilities, stratified by age and sex. We will assess differences in mode of presentation and cancer stage for breast, prostate, lung and colorectal cancers between patients with and without intellectual disability, adjusting for sociodemographic factors. We will compare differences in treatment and survival between the two cohorts. Patient and public involvement will be built into the study, guiding the research team throughout, with co-design and lived experience being central to interpretation and dissemination. Implications for policy/practice: This study will provide Irish population-level data on cancer incidence, diagnostic pathways, treatment patterns, and outcomes for people with intellectual disabilities. It will identify areas of critical importance in terms of diagnostic pathways and variations in the provision of care this population receives. This study will highlight any policy gaps or inequities experienced by people with intellectual disabilities and generate evidence to inform inclusive cancer policy and care. Deliverables will include the development of a specific cancer task group, peer-reviewed publications, accessible resources, position paper and policy briefs that support the inclusion of targeted approaches to address inequalities and inequities and inform national cancer policy and practice.
