Curious on what members know about the 2 PSA tests. My recent bio: finished 6 cycles of docetaxel 11 weeks ago while on ADT(elligard) and xtandi. PSA dropped from 5.7 to 0.12 (roughly halving every 3 weeks). Still on ADT and xtandi. PSA test this week was 0.3, four weeks after the 0.12 test. However, the lab did not have the test code for "monitoring PSA" so they did the "screening PSA". It was a different lab, 1000 miles from my usual lab but under the same corporate umbrella and used the same equipment from what I can tell.
Was surprised by the PSA increase given most of what I had read suggested the PSA would likely continue dropping a bit longer. I know different labs can introduce variability. I could not find much on the web regarding the 2 protocols, other than a monitoring test can be more accurate. ChatGPT was not very helpful. My MO wants to continue monthly testing as expected. He was neutral on whether I should be concerned or not. I won't be able to use my usual lab until mid April.
Anyhow, anyone out there have a similar experience or has some insights?
Thanks.
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jap41452
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Thanks. Agreed. I should have been more precise. The .3 was actually reported as 0.30. The prior .12 value was reported as 0.12. But perhaps the 0.30 was actually 0.3 and the value was entered into the reporting system with the extra precision. I know these values are still in the mud but I'm more concerned about the seemingly unexpected upswing.
Apparently you like many others here (which includes me) suffer from P.F.A. otherwise known in the A I world as Psa Fucking Anxiety. Watch the decimal point and zero positions.
From what I can find they are pretty much the same test. In my case the same lab equipment but different locales and maybe a slightly different diagnostic protocol. The monitoring test is more expensive than the screening test at least for the lab system I'm using. Just the different locale may introduce some variability. The reason for the change was the most recent lab oddly did not recognize the test code for the monitoring test.
To add some insight to all of this I have 1 more test at the recent lab a month from now and then back to my usual lab 2 months from now.
Bingo now it makes sense. When I had my annual my GP muttered the MA ordered the wrong test when I called the office for an add on. So one was total PSA and the other was a complete PSA analysis.
I went through PFA after my prostatectomy. I was getting high res test from 3 to 4 different labs mostly because I have serious trust issues with the entire medical industry. I discovered that there at least 5 different assay methods for PSA testing and I proved that blood samples taken the same day can have drastic deviations depending on the lab and the assay method being used.
That being said, the lesson learned was "use the same lab and assay method for subsequent / sequential testing". Then I switched my post prostatectomy treatment over to MD Anderson. They report no values less than 0.1. They said all values below that are noise. At least now I have much less anxiety. After 1 year of post radiation and ADT testing. I'm still in remission. I can't imagine sweating such small changes in the ultra sensitive testing. That has potential for an emotional roller coaster. Our journey is difficult enough without that factor IMO
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Could my psa variations be a result of lab errors ?
PSA Doubled in 2 Months 
PSA slooooowly rising.
PSA Jumped
PSA test didn't detect my cancer. What about post treatment monitoring?
