Immediate Curative vs Conservative Treatment in Older Men With M0, High-risk Prostate Cancer

This study is comparing two approaches for older men with high-risk prostate cancer that has not spread: immediate curative treatment (such as radiation or surgery) versus a more conservative "watch and wait" approach, to see which leads to better quality of life and outcomes in men 75 and older. **You may be eligible if...** - You are 75 years of age or older - You have been diagnosed with prostate cancer within the past 6 months - Your cancer has a high-risk Gleason score (grade group 4 or 5) or is locally advanced (T3 or T4 stage) - Your tumor is visible on MRI or can be felt on physical exam - You are in good overall health based on a medical and geriatric assessment **You may NOT be eligible if...** - Your cancer has spread to lymph nodes or distant organs (metastatic) - You are under 75 years old - Your overall health is too poor to tolerate treatment - You have already started treatment for prostate cancer Talk to your doctor to see if this trial is right for you.