Comparing 0.5 mg Dutasteride vs Placebo Daily in Men Receiving Androgen Ablation Therapy for Prostate Cancer

Inclusion Criteria: * Able to give informed consent * Age\_\>45and\<\_80 * Histological confirmed adenocarcinoma of prostate * Has received external beam radiation,brachytherapy or radical prostatectomy for the treatment of prostate ca * Candidate for intermittent androgen ablation * Minimum of 3 PSA values above nadir taken at least 1 month apart * Serum testosterone \>\_250ng/dl,ECOG 0 or 1 * Negative bone scan within 12 months of visit 1 * Able to swallow and retain oral medication Exclusion Criteria: * Previous treatment with chemotherapy * Hormonal therapy with in last year * Glucocorticoid with in last 3 months * LHRH analogues with in previous year * Ketoconazole * Non Steroidal anti-androgens with in previous year * Concurrent or previous use of Finasteride Dutasteride 5a reductase inhibitor anabolic steroids * Over the counter or herbal prep such as saw palmetto selenium or vitamin E within last year * May not be receiving any other investigational drug with in last 30 days * Evidence of distant metastases * Has received adjuvant or neoadjuvant ablation in past 12 months * Unstable serious co-existing medical condition * Abnormal liver and kidney functions * Previous malignancy not including curative treated basal cell carcinoma of skin with in 5 years and bladder cancer with in past 2 years * Known hypersensitivity to any 5a-reductase inhibitor or to any drug chemically related to dutasteride * Known hypersensitivity to bicalutamide.