Leuprolide Acetate or Goserelin Acetate Compared With Observation in Treating Patients With High-Risk Prostate Cancer Who Have Undergone Radical Prostatectomy

PRIMARY OBJECTIVES: I. To compare the difference in the biochemical progression-free survival rate (bPFS) at 2-years between immediate androgen deprivation therapy (ADT) for nine months in high risk prostate cancer patients following radical prostatectomy and a similar high risk patient population followed without initiation of immediate ADT treatment. SECONDARY OBJECTIVES: I. To determine the difference in bPFS, prostate cancer specific survival, and overall survival between immediate ADT for nine months and observation for high risk prostate cancer patients following radical prostatectomy. II. To evaluate the toxicity profile and quality of life (QOL) measured by Functional Assessment of Cancer Therapy-Prostate (FACT-P) and linear analogue self assessment (LASA) between two treatment arms. TERTIARY OBJECTIVES: I. To explore if serum and urine biomarker(s) levels at study entry, 9 months, or 24 months in the two treatment arms are correlated with biochemical progression-free survival rate. II. To explore if \> 5 circulating tumor cells (CTCs) or circulating endothelial cells (CECs) following study treatments are associated with biochemical progression-free survival rate. III. To explore the prognostic and predictive value of tissue based biomarkers in high risk prostate cancer patients. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM A: Patients receive leuprolide acetate intramuscularly (IM) on day 1 OR goserelin acetate subcutaneously (SC) on day 1. Courses repeat every 3 months for 9 months in the absence of disease progression or unacceptable toxicity. ARM B: Patients undergo observation every 3 months for 9 months. After completion of study treatment, patients are followed up every three months for 2 years.