Effects of androgen deprivation on white matter integrity and processing speed in prostate cancer patients

Studies have associated chemotherapy-elicited changes in cognitive function with impaired white matter integrity in cancer patients. Androgen deprivation therapy (ADT) may lead to cognitive deficits in prostate cancer patients; however, whether ADT influences white matter integrity has never been investigated. In a prospective study, 15 men with non-metastatic prostate cancer receiving ADT and 15 not receiving ADT (controls or CON), comparable in age and years of education, participated in N-back task, flankers' task, and quality-of-life (QoL) assessments. All participants underwent diffusion tensor imaging of the brain at baseline and at 6 months. Imaging data were processed with published routines. The results of a paired t-test of 6-month follow-up vs. baseline were evaluated at a corrected threshold for the whole brain each in ADT and CON. ADT patients showed significantly worse 1-back accuracy during follow-up, but the two groups did not differ in 2-back accuracy, 1- or 2-back reaction time (RT), flankers' task RT or QoL across time points. In ADT, significantly reduced fractional anisotropy (FA) was noted in the corpus callosum, forceps minor/anterior thalamic radiation, superior and posterior corona radiata. The differences in FA correlated significantly with changes in 2-back and flankers' task RT. No significant FA changes were noted during follow-up in CON. Six-month ADT affects white matter integrity, and the deficits were associated with slower processing speed. These findings add to the literature supporting the deleterious effects of androgen deprivation on the brain and cognition in prostate cancer patients.