Cognitive Effects of Androgen Receptor Directed Therapies for Advanced Prostate Cancer

PRIMARY OBJECTIVES: I. To compare cognitive function and associated mediators of cognitive function (quality of life, depression, pain, and fatigue) of men with metastatic castration-resistant prostate cancer (mCRPC) or metastatic hormone sensitive prostate cancer during treatment with enzalutamide (mCRPC only) and abiraterone acetate (mHSPC or mCRPC). SECONDARY OBJECTIVES: I. To identify characteristics of men with mCRPC associated with change in cognitive function during treatment with androgen receptor (AR) directed therapy. II. To compare quality of life and associated factors, including fatigue, pain, and depression, of men with mCRPC during treatment with enzalutamide and abiraterone acetate. TERTIARY OBJECTIVES: I. To analyze whether single nucleotide polymorphisms (SNPs) may be associated with change in cognitive function during treatment with AR directed therapy. II. To compare the functional and structural components of the brain over time and between the brains of men with mCRPC treated with enzalutamide or abiraterone acetate using diffusion tensor imaging (DTI), functional MRI (fMRI), arterial spin labeling (ASL), and other advanced neuroimaging techniques. OUTLINE: Treatment patients with metastatic castration-resistant prostate cancer are randomized to 1 of 2 arms. Control patients receiving long term androgen deprivation therapy will be assessed with the same measures as a control arm. ARM I: Patients receive standard of care treatment with gonadotrophin releasing hormone (GnRH) agonist/antagonist therapy. Patients also receive abiraterone acetate orally (PO) and prednisone PO twice daily (BID) in the absence of disease progression or unacceptable toxicity. Patients then undergo cognitive assessment comprising of neuro-cognitive tests and assessments of overall quality of life, fatigue, pain, and symptoms at baseline, 3, 6, and 12 months. Patients also undergo MRI program for 40 minutes comprising of DTI, fMRI, ASL MRI, Magnetization Prepared Rapid Gradient Echo (MPRAGE) MRI, Fluid attenuated Inversion Recovery (FLAIR) MRI, and blood oxygenation level-dependent (BOLD) MRI at baseline and 3 months. ARM II: Patients receive standard of care treatment with GnRH agonist/antagonist therapy. Patients also receive enzalutamide PO QD in the absence of disease progression or unacceptable toxicity. Patients undergo cognitive assessment and MRI program as in Arm I. ARM III: Patients receive standard of care treatment with GnRH agonist/antagonist therapy and undergo cognitive assessment and MRI program as in Arm I.