Castration Compared to Castration Plus Metformin as First Line Treatment for Patients With Advanced Prostate Cancer

Inclusion Criteria

• •1. Men with metastatic prostate cancer that require castration therapy with either using an LHRH analogue or surgical castration are eligible. Complete androgen blockade using anti-androgen therapy prior to castration or up to 4 weeks following castration therapy is permitted to prevent disease flare. Thereafter anti-androgen therapy may continue or be discontinued based on treating physicians preference.
• •OR
• •2. Any men with prostate cancer who are candidates for castration therapy despite no evidence of definite metastatic disease including patient with biochemical failure or 'rising PSA' are also permitted to enter study provided castration therapy is planned for a minimum of a year. Patients with biochemical failure prior to enrolment should have also have already received appropriate salvage therapy. Men with prostate cancer who have already started castration therapy are also permitted to enter study provided castration therapy was initiated within one month of study entry.
• •OR
• •3. Men with prostate cancer previously treated with castration therapy for management of localized prostate cancer in the adjuvant setting or in combination with radiation therapy are permitted to enter study provided they currently have known metastatic disease and have non-castrate testosterone levels (Testosterone \> 50 ng/dL).
• •4. An ECOG performance status of 0-2.
• •6. Patients must have provided informed consent, be willing to have blood specimens taken, and exhibit no severe other medical or psychiatric problems.