Er det lavere kreftprevalens blant demente enn blant kognitivt klare pasienter på sykehjem? En diskusjon av forskjeller i prevalens og assosierte faktorer

BACKGROUND: Life expectancy is continuously increasing worldwide, thus increasing the likelihood of individuals developing dementia and cancer. Dementia causes symptoms that render difficult communication and interaction with patients. A possible consequence is difficulty in identifying possible cancer symptoms. Prior studies indicate lower cancer prevalence among patients with dementia. The reason for this is not studied closely and studies provide different explanations. In nursing homes (NH), patients both with and without dementia reside. Thus, it is an appropriate arena to study cancer prevalence. PURPOSE: To investigate if the prevalence of cancer among NH patients with dementia is different from that of NH patients without dementia. In addition, relevant factors that may shed light on this relationship are explored. METHOD: An epidemiologic cross-sectional study based on a comprehensive data set from a sample of Norwegian NHs. For patients with and without dementia, comparisons are made of cancer prevalence, and of number of diagnoses and number of medications, in particular analgesics. Furthermore, the study investigates if variations in cancer diagnoses can be explained by the same variables, as well as by neuropsychiatric status, depression, general medical health and level of active daily living. RESULTS: There is significantly lower prevalence of cancer among NH patients with dementia than among those without. Furthermore, patients with dementia have fewer diagnoses and use less medication. The regression supports these findings, and shows that the number of analgesics used and patients' general medical health contribute to explaining variation in cancer. CONCLUSION: Findings show significantly lower cancer prevalence among patients with dementia. The study explores several different interpretations of this difference and discusses its weaknesses. The analyses and insights from prior research support the interpretation of the results as undetected cancer being potentially widespread among patients with dementia. Future research should investigate this further