Does ADT truly impair cognitive function?

Course and Predictors of Cognitive Function in Patients With Prostate Cancer Receiving Androgen-Deprivation Therapy: A Controlled Comparison. By Gonzalez et al. 2015

 

Key sentence from the paper: “The odds of impaired performance in ADT recipients were approximately 70% higher than in controls within 6 months and > twice that of controls within 12 months.

 

For the full abstract, see: http://www.ncbi.nlm.nih.gov/pubmed/25964245

 

Commentary: This is the best study to date on the impact of ADT on cognitive function, and it has several important findings. The first is that it confirms that ADT causes cognitive impairment in prostate cancer patients, so MDs should advise patients of that before starting them on ADT

This paper is from the same research group at the Moffitt Cancer Center in Tampa, FL, who published a meta-analysis last year of the previous studies on this topic [Blogged on July 31st, 2014]. What is interesting, and not addressed in their new paper, is a discrepancy in the cognitive domains that are affected by ADT. For example, in their meta-analysis they flagged visuomotor ability as the cognitive area most likely to be affected by ADT. Here, they found that no single domain stood out. To quote them, “there is no domain specific pattern of cognitive impairment associated with ADT.” That is quite a different conclusion than in their previous article and suggestsed that there is still a need for research with larger sample sizes to clarify what cognitive processes are most likely to be impaired by ADT.

In the new paper the authors looked at the genes of their research participants. They found that patients on ADT with one particular genetic variant (i.e., with the fancy name of “GNB3 single-nucleotide polymorphism rs1047776”) were more likely to show significant progression of cognitive impairment over time. This suggests that with the emergence of personalized medicine, it may be possible for physicians to tell patients whether they are more or less likely to be negatively affected in terms of cognitive function by ADT. However, such a process would require the patient to undergo genetic testing, which may be associated with additional costs. Until we discover ways to overcome the cognitive impact of ADT, such genetic profiling may help patients offered ADT decide whether to go on that treatment.  

 

Gonzalez BD, Jim HS, Booth-Jones M, Small BJ, Sutton SK, Lin HY, Park JY, Spiess PE, Fishman MN, Jacobsen PB. 2015. Course and Predictors of Cognitive Function in Patients With Prostate Cancer Receiving Androgen-Deprivation Therapy: A Controlled Comparison. J Clin Oncol. 33(18):2021-7.