I was getting my PSA checked every 6 months until I had a 9.4. The recheck 2 months later was 12.3. My urologist/surgeon recommended a prostatectomy immediately . He later told me the prostate was fully engorged with cancer. I had the surgery just in time. With your PSA at 50.64 your urologist should be recommending immediate surgery. If they won't, you need to see another doctor.