A scoping review documenting cancer outcomes and inequities for adults living with intellectual and/or developmental disabilities

Introduction: Emerging evidence suggests adults with intellectual and/or developmental disabilities (IDD) may be at risk of inequities in cancer experiences and outcomes. Individuals with IDD may experience multiple barriers that could worsen outcomes and experience. These barriers may be connected to features of IDD or the healthcare system overall. Future research and program planning to support adults with IDD and cancer must be informed by evidence that acknowledges potential disparities, underlying determinants, and knowledge deficits. Objective: We conducted a scoping review to systematically map the evidence describing and comparing cancer related outcomes along the cancer continuum from risk to mortality for adults with IDD. We identified specific factors observed to influence those outcomes. Methods: We followed the expanded Arksey & O'Malley framework for conducting the scoping review. We searched for literature in PubMed and Embase databases. We abstracted cancer-related data, IDD-related data, and data related to physical and social determinants of health. Results: Of the 2796 studies retrieved, 38 were included for review. Most studies focused on screening outcomes and experiences. Studies reported that adults with IDD experienced inequities at various points along the cancer continuum. Numerous social and physical determinants of health influenced the experiences and outcomes of adults with IDD. Conclusion: This scoping review identified significant gaps in the literature. Of note was the focus on cancer screening and lack of attention to larger systems of oppression that may influence poor cancer experiences and outcomes for adults with IDD. There is strong need to improve both quality and quantity of research in this area.