Risk of dementia in prostate cancer survivors: A nationwide cohort study in Korea

Objectives: To investigate the effects of prostate cancer (PC) and various treatment modalities for PC, specifically androgen deprivation therapy (ADT), on the risk of dementia and dementia subtypes in PC survivors. Material and methods: A total of 51,252 patients newly diagnosed with PC from 2007 to 2013, who had no prior diagnosis of cancer or dementia, were included and matched with 209,659 non-cancer control. The screening subset was comprised of subjects who participated in a health screening program. We used Cox proportional hazards model to estimate the relative risk of dementia and dementia subtypes according to the primary treatment for the PC. Results: Compared to non-PC matched controls, PC survivors showed slightly higher risk for dementia and Alzheimer disease (AD) only in the screening cohort. While PC survivors who underwent ADT were higher risk for dementia and AD, patients who underwent surgery were lower risk for dementia and AD, compared to the non-cancer population. Compared to surgery, ADT, surgery + ADT, and active surveillance/watchful waiting showed a significantly elevated risk for dementia. Conclusion: PC survivors had slightly higher risk for dementia compared to non-PC controls, which might be related to the screening effects of PC. The risk for dementia was most prominent among PC patients who underwent ADT, followed by patients who underwent AS/WW, and those who underwent surgery+ ADT. This finding suggests that individualized ADT strategies that consider the survival benefit and underlying dementia risk in PC survivors are necessary. (c) 2020 Elsevier Inc. All rights reserved.