Treating advanced prostate cancer with androgen deprivation therapy (ADT) does not increase risk of Alzheimer’s disease, according to research published in the Journal of Clinical Oncology.
ADT is prescribed to men with advanced prostate cancer because it eliminates testosterone in the testosterone-fueled disease. The therapy has shown to be highly effective at stopping the progress of prostate cancer, but recent observational studies have associated its use with an increased risk of dementia and Alzheimer’s disease. Some methodological deficiencies have since been found in the studies that reported this association, prompting researchers to further investigate the matter.
Researchers led by Laurent Azoulay, PhD, Associate Professor of Epidemiology and Oncology, McGill University (Canada), conducted a study to determine the potential association of ADT and an increased risk of dementia, including Alzheimer’s disease, in patients with prostate cancer. A total of 30,903 men with newly diagnosed, non-metastatic prostate cancer from 1988 to 2015 were sampled from the United Kingdom’s Clinical Practice Research Datalink. Researchers used time-dependent Cox proportional hazards models to estimate adjusted hazard ratios (HR) with 95% CIs of dementia associated with the use of ADT compared with non-use.
Results indicated that 799 patients were newly diagnosed with dementia (incidence, 6.0; 95% CI, 5.6 to 6.4) per 1000 person-years over the course of a mean follow-up of 4.3 years. ADT use was not found to be associated with an increased risk of dementia compared with non-use (incidence, 7.4 vs 4.4 per 1000 person-years, respectively; HR, 1.02; 95% CI, 0.87 to 1.19). A secondary analysis, assessing risk variation with cumulative duration of use and by ADT type, showed that duration of use and no single type of ADT were associated with an increased risk of dementia.
Researchers acknowledge that additional studies are necessary to confirm these findings. Nonetheless, the American Society of Clinical Oncology offered its full support of the study because of its immediate clinical importance.
“If patients believed that ADT doubled their risk of Alzheimer disease they may be reluctant to take it for their cancer. Thus, our analysis should be welcome news for men whose prostate cancer is being controlled with ADT,” said co-author Farzin Khosrow-Khavar, doctoral candidate, McGill University.
