Cancer and Cognitive Function: The PATH Through Life Project

Background: A limited number of studies have shown that cancer diagnosis plays a protective role in Alzheimer's disease. However, the effect of the cancer diagnosis on general cognitive function/cognitive decline has not been previously examined. The aim of this study was to investigate the relationship between cancer diagnosis and cognitive function and mild cognitive impairment/disorders (MCI/MCD), adjusting for cancer treatments. Methods: These data were drawn from the Personality and Total Health (PATH) Through Life Study, a population-based Australian cohort study. A total of 2,547 participants (age range 60-66 years; 48.4% women) who answered cancer-related questions were included in analyses. Random effects linear and logistic models were used to analyze 8-year follow-up data. Results: Participants who were diagnosed with cancer at or prior to baseline (n = 166) had higher levels of physical conditions and depression compared with those who received cancer diagnoses during follow-ups (n = 346) and those who reported no cancer history (n = 2,035). A main effect suggested an improvement in processing speed (p < .01), working memory (p < .05), and simple reaction time (p < .05) for those who received the cancer diagnosis after baseline when compared with those without a cancer diagnosis. However, these group differences were no longer significant when adjusted for cancer treatments. Those with a cancer diagnosis at or prior to baseline reported poorer processing speed when compared with those without a cancer diagnosis, even after adjusting for the treatments. Conclusions: A cancer diagnosis alone did not play a protective role for cognitive function and cognitive impairment in this population of older community-living individuals.