Androgen Deprivation Therapy and Risk of Dementia

Date of ISAC Approval: 
05/07/2016
Lay Summary: 
Androgen deprivation therapy is the mainstay treatment for advanced prostate cancer. However, this treatment has been linked to cognitive impairment and concordantly, low testosterone levels have been linked to Alzheimer's disease and dementia. To date, only one observational study has examined the association between this therapy and Alzheimer's disease. The aim of this study is to assess whether patients diagnosed with prostate cancer who are treated with androgen deprivation therapy are at an increased risk of dementia (including Alzheimer's disease), in comparison to patients who are not treated with this therapy.
Technical Summary: 
The association between androgen deprivation therapy (ADT), a mainstay treatment for advanced prostate cancer, and dementia is controversial. Thus, the objective of this study will be to use the Clinical Practice Research Datalink to assess whether the use of ADT is associated with an increased risk of dementia in a cohort of approximately 45,000 patients newly-diagnosed with prostate cancer. The use of ADT will be treated as a time-varying variable, with exposure lagged by one year for latency considerations and to minimize reverse causality. Time-dependent Cox proportional hazards model will be used to estimate adjusted hazard ratios (with 95% CI) of incident dementia associated with use of ADT when compared with non-use of ADT. This study will address an important safety question in an older population already at increased risk of dementia.
Health Outcomes to be Measured: 
To assess whether the use of ADT is associated with an increased risk of dementia
Collaborators: 

Samy Suissa - Chief Investigator - McGill University
Armen Aprikian - Collaborator - McGill University
Farzin Khosrow-Khavar - Collaborator - Sir Mortimer B Davis Jewish General Hospital
Hui (Hoi) Yin - Collaborator - Sir Mortimer B Davis Jewish General Hospital
Dr Laurent Azoulay - Corresponding Applicant - McGill University
Rej Soham - Collaborator - University of Toronto