A literature review of cancer diagnostic tests and treatments in adults with intellectual disability.

Background: Adults with intellectual disabilities have significantly lower rates of routine cancer screening and cancer is often diagnosed at more advanced stages. Some studies highlight gaps that exist in national screening programmes for cancers such as breast, cervical and colorectal. Evidence in the intellectual disability population points towards factors such as limited screening education, distrust in healthcare providers, and challenges in providing consent, leading to limited uptake of screening programmes. While there are many contributing factors to these inequalities, changes in individuals' health status may go unrecognised for longer because of their intellectual disability. The aim of this literature review is to explore cancer diagnostic approaches and treatment options for adults with intellectual disability and examine barriers to accessing diagnostic procedures and treatments. Methods: Five electronic databases were systematically searched: Cinahl Ultimate, Medline, PsycINFO, PubMed, and Web of Science. Thematic analysis was completed using the Braun and Clark Six Step process. Results: Four main themes emerged from 28 included studies: Prevention, education, adaptation, and ethical practice. Prevention encompassed individuals receiving regular screening and barriers that prevented access. Educational tools that explained the importance of screening reduced feelings of stress and anxiety. Case studies illustrated how specific treatment plans were adapted for patients with intellectual disability. Autonomy and honesty were themes throughout many studies, in terms of treatment, education, and diagnostics. It was determined that patients should be involved in decision making and be aware of their cancer diagnosis unless there are contra-indications. Conclusion: Adults with intellectual disability face considerable barriers when accessing cancer diagnosis and treatment. Barriers, including living conditions, communication difficulties and age, contributed to later cancer diagnosis and worse outcomes, compared to the general population. The successful use of education and tailored treatments were enabling factors.