PSA anxiety

After almost three years post prostatectomy and follow-up standard (screening type) PSA tests being undetectable, last June I persuaded my doctor to order the ultra-sensitive PSA because I know I have a high risk for recurrence. The result was undetectable. In September I had a follow-up visit at Mayo and a repeat PSA there. It was undetectable but to my surprise they did the standard PSA. I thought about asking for the ultra-sensitive but decided to wait until this week to get it. It turned out to be 0.11 . This of course worries me a lot.
The doctors in the small town where I live don't agree with getting the ultra-sensitive PSA, nor does my Mayo clinic doctor but I am glad I insisted on it. I just wish I had insisted back in September. But now I have this worry.
Anyway, here I am today with this result. I have asked for a repeat ultra-sensitive PSA the first week in January, a month after the 0.11 result, and do not plan to tell my family about the 0.11 because I really don't want to dampen the holidays. Mostly I am writing this to vent a bit but I'd also like to learn what others think and would do in my place. Would you advise a repeat ultra-sensitive PSA sooner?

I know you are correct that no treatment decision would be made if I got an earlier test but I'd sure feel better if a repeat was undetectable next week. That's the problem with PSA anxiety. I guess what I am really wondering is how variable is the ultra-sensitive PSA? Plus or minus what? I have not been able to find out.

There's significant variation due to multiple causes. First off, never compare one test result to another if they were done at different labs (or if you discover that your one existing lab switched/updated test equipment) because they all have their own calibration standards and methods. Second, once you stick with just one test, the test accuracy variation is often beyond the minimum reportable resolution...so if your score goes from 0.11 ng/mL to 0.12 the reported result went up but is there really more PSA in your blood...maybe/maybe not, the test is not that accurate. Third, the absorption of PSA into your blood serum varies day-to-day, hour-by-hour. Although this would be impossible/impractical to obtain statistically significant limits on this, I've seen reports of someone going every day for a month to get a PSA test and their results varied +/- 30%. What you ate today, and how long ago, and other similar body biology variations all play a (small) factor, for example, in what your blood serum constituents are at a test any given part of the day.

So you could test it again before your scheduled test 1st week in Jan, but what if it comes back 0.09? What if it comes back 0.12? I know you'd like it to come back 0.01, but ... up to you. I wouldn't .

Argent,

Yeah, little moves are nerve-wracking, but one wonders what they mean. Most docs won't act on PSA movement post RALP unless you have several rises in a row over a period of several months. 0.1 or higher is less important, it seems, than a steady trend. And, so far, you don't have a trend.

As far as the accuracy of the test overall, the answer to that question is actually difficult to come by--the big labs like Labcorp and Quest don't publish their statistics--but it appears that the generally accepted accuracy (noise) values are in the range of +/- 0.01 or even 0.02. So changes in the 3rd decimal point area aren't even looked at--unless they show steady movement from non-detect upwards. As someone else pointed out, the key points are to always have your blood draw at the same site, at the same time of day, under the same conditions as far as you can. Then the data can be compared.

Yup, I’m like you I’d hit it hard too..