Prostate cancer is the most common form of cancer among American men. The incidence of prostate cancer increases with age and the median age at diagnosis is 67 years. Apart from age and ethnic origin, a positive family history is the strongest known risk factor for prostate cancer. In 2011, it is projected that 240,890 men in the United States will be newly diagnosed with prostate cancer and 33,720 men will die of the disease. The disease has four distinct phases of progression: 1) localized, 2) recurrent, 3) metastatic, and 4) hormone-refractory disease. Not all men will progress through each phase as prostate cancer is typically slow growing and may not progress to a life-threatening disease during a patient's lifetime. Prognosis depends primarily upon the disease burden at diagnosis. Treatment choices for localized or recurrent prostate cancer are active surveillance (watchful waiting), radical prostatectomy, or radiotherapy. For patients with metastatic disease, the mainstay of treatment is androgen-deprivation therapy. The choice of therapy is typically based upon patient factors such as tumor characteristics, risk of recurrence and life expectancy of the patient. Until recently, the treatment of hormone or castration-resistant prostate cancer has been largely palliative; however, emerging therapies include hormonal, cytotoxic, immune, and targeted interventions that are aimed at improving survival.