What’s the latest on a possible link between ADT and the risk of dementia?

If you have been following this blog, you know that we have reported on a fair number of studies suggesting that ADT increases men’s risk of cognitive impairment. We have also noted that the literature is inconsistent. Whereas most papers have suggested that there is an elevated risk of dementia for patients on ADT (compared to matched control patients), one recent paper by Quinones and colleagues (2019) failed to find such an association. Here though is a study that reports on data from a sample of prostate cancer patients that is two orders of magnitude larger than the sample in the Quinones et al. (2019) study.

As with many studies involving a large sample of prostate cancer patients, the authors took their data from the SEER database. Over 100,000 men with localized or locally advanced disease were included in the study, 38,000 of whom received ADT within 6 months of diagnosis. Patients with metastatic disease or a previous history of dementia were not included in the sample.

So what did they find? ADT was associated with a 17% higher risk of all-cause dementia and a 23% higher risk of Alzheimer’s compared to men with similar stage disease who did not receive ADT. The authors also found that the length of time the men were on ADT mattered. Longer duration of ADT (i.e., ≥ 7 months) was associated with a 25% elevated risk of all-cause dementia and a 34% higher risk of Alzheimer’s dementia.

Those are among the strongest data reporting an association between ADT and cognitive impairment. These results may be seen as a good case for limiting the length of time one is on ADT with LHRH agonist drugs, if there is little or no evidence of disease progression.

To read the study abstract, see:

https://www.ncbi.nlm.nih.gov/pubmed/31784699

Krasnova, A., Epstein, M., Marchese, M., Dickerman, B.A., Cole, A.P., Lipsitz, S.R., Nguyen, P.L., Kibel, A.S., Choueiri, T.K., Basaria, S., Mucci, L.A., Sun, M., & Trinh, Q.D. (2019). Risk of dementia following androgen deprivation therapy for treatment of prostate cancer. Prostate Cancer and Prostatic Diseases. Advance Online Publication. doi: 10.1038/s41391-019-0189-3