Bicalutamide With or Without Metformin for Biochemical Recurrence in Overweight or Obese Prostate Cancer Patients (BIMET-1)

1 Cycle = 28 days = 4 weeks. Treatment will be administered on an outpatient basis ӿ Metformin starting dose is 500 mg BID, will be gradually increased to target dose of 1000mg BID. Treatment ARM A Cycles 1 - 2: Observation without treatment Cycles 3 - 8: Bicalutamide 50 mg daily, orally, continuously to the end of study (week 32). Treatment ARM B Cycles 1 - 2: In order to minimize gastrointestinal discomfort, metformin dosing will be ramped up over a period of 2 weeks. Metformin treatment will be started at 500 mg BID (Dose Level -2) and increased by an increment of 500 mg daily every week +/- 2 days provided no grade 2 or higher gastrointestinal toxicity is noted. If grade 2 or greater gastrointestinal toxicity occurs during the first 4 weeks of treatment, the subject will be evaluated every 2 weeks until resolution of toxicity to grade 0 or 1 and, then, the metformin dose will be increased to the next dose level. The target dose of metformin is 1000 mg BID.