@johndavis60 Quest and Labcorp use different instruments, so their PSA test results are not comparable. Indeed, stick with the same lab. Also, results from a regular PSA test (limit of detection is 0.1) and an ultra-sensitive PSA test are not comparable (again different instruments/procedures), although results might be close. Also, there is lab variance, so you might see slight changes in your PSA result even if you go to the same lab consistently. For example, I had PSA tests done at the same lab within 5 days of each other. The first was 0.11 and the second was 0.12. I put no stock in the 0.01 increase and just attributed it to normal lab variance.

Your numbers look like a real trend though. Congrats! Hope it keeps trending down below detection and stays there.