Testing Interruption of Hormonal Medications in Patients Responding Exceptionally to Therapy for Metastatic Prostate Cancer, (A-DREAM)

This phase II trial examines antiandrogen therapy interruptions in patients with hormone-sensitive prostate cancer that has spread to other places in the body (metastatic) responding exceptionally well to androgen receptor-pathway inhibitor therapy. The usual treatment for patients with metastatic prostate cancer is to receive hormonal medications including a medication to decrease testosterone levels in the body and a potent oral hormonal medication to block growth signals from male hormones (like testosterone) in the cancer cells. Patients whose cancer is responding exceptionally well to this therapy may take a break from these medications according to their doctor's guidance. This trial may help doctors determine if stopping treatment can allow for testosterone recovery.

PRIMARY OBJECTIVE: I. To determine the proportion of men who experience 18-month treatment-free interval from therapy with eugonadal testosterone (to \>= 150 ng/ml) after treatment interruption. SECONDARY OBJECTIVES: I. To determine time to eugonadal testosterone (\> 150 ng/dl). II. To determine duration off-treatment. III. To assess changes in quality of life as follows: 1. To assess changes in patient-reported quality of life as assessed by the Functional Assessment of Cancer Therapy- Prostate (FACT-P) total score from baseline to 24 months after treatment interruption. 2. To assess changes in the FACT-P subscales (i.e., physical well-being, social and family well-being, emotional well-being, functional well-being, and prostate cancer subscale) from baseline to 24 months after treatment interruption. 3. To assess changes in the FACT-P total score and subscales (i.e., physical well-being, social and family well-being, emotional well-being, functional well-being, and prostate cancer subscale) from baseline to the remaining post-baseline time points (i.e., 6, 12, and 18 months) after treatment interruption. OUTLINE: Patients stop both hormonal medications (medication to decrease testosterone levels in the body and potent oral hormonal medication to block growth signals from male hormones in the cancer cells). Patients are then followed every 12 months for symptoms. Patients with an increase in prostate specific antigen (PSA) level to greater than or equal to 5 ng/ml, changes on imaging studies suggesting that their cancer is growing back, or symptoms that the doctor thinks is related to their cancer growing back, resume both hormonal treatments. After completion of study treatment, patients are followed up every 6 months for 10 years from registration or withdrawal from the study or death.