Recent studies summarized on this website on December 30th, 2015 and November 7th, 2016 concluded that hormonal therapy of prostate cancer was linked to an increase in dementia and Alzheimer’s disease. Now a recent study published in the Journal of Clinical Oncology and summarized in the February 6th, 2017 e mail issue of Prostate Cancer News Today has concluded the opposite, namely that prostate cancer patients receiving androgen deprivation therapy (ADT) are not at increased risk of dementia or Alzheimer’s disease.
Cognitive impairment is a known side effect of declining testosterone, in general, so it is naturally of concern with ADT. However the study authors noted that “there is a significant difference between cognitive limitations and the biological mechanisms associated with dementia.” Because ADT is so often given to older men, very careful statistical analysis is required to assert a causal relationship.
Using data from the United Kingdom’s Clinical Practice Research Datalink (CPRD), researchers analyzed the medical records of 30,903 patients diagnosed with nonmetastatic prostate cancer over 27 years. During a mean follow-up of 4.3 years, 799 patients were diagnosed with dementia. Researchers did not find a link between ADT and the condition. Secondary analyses — assessing whether the risk varied with the type of ADT or length of use — also failed to show a connection. There are side effects to every medication. The authors note that “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.”