Metformin in Castration-Resistant Prostate Cancer

Metformin is a medication that is prescribed for people with diabetes to help the body
respond better to its own insulin and decrease sugar production by the liver. This helps
control the body's blood sugar level and is approved by the FDA for the treatment of
diabetes. Participant's in this research study will already be receiving androgen
deprivation therapy (ADT) for prostate cancer. ADT is considered standard of care for
prostate cancer. Changes in the participant's metabolism, including changes in insulin and
blood sugar levels, are often seen as a result of this type of hormone therapy. Some
studies have shown a relationship between insulin and prostate cancer. These studies have
suggested that insulin may signal tumor cells to grow. Other studies suggest that people
receiving metformin treatment for diabetes may enjoy better outcomes from their prostate
cancer then other similar patients who are not treated with metformin.