A total of 1,643 men with localized prostate cancer were enrolled in a trial to assess treatment efficacy, with 545 randomly assigned to active monitoring, 553 to prostatectomy, and 545 to radiotherapy. Prostate cancer-specific mortality was low after 15 years of follow-up, regardless of treatment. Thus, deciding on therapy entails weighing the benefits and drawbacks of treatments for localized prostate cancer.