6-week Post-Op PSA Result - Utility of Ultrasensitive Tests When Good Pathology?

[jazj]

I just got back my 6-week post op PSA results. < 0.02. I had asked if I could get the test done anywhere and they said yes as long as it's ultransensitive. I love the lab at my PCP's clinic. It's a state of the art facility and all my blood draws are 5 min in and out including parking. So I asked my PCP to put in an order for an Ultrasensitive PSA test. He provided the details of the test, it's Abbott Chemiluminescent Microparticle Immunoassay (CMIA) methodology. I didn't run this past my Urologist at the other institution as I assumed it was ultrasensitive. Well this is why my PCP is not a Urologist. As obviously it's not ultrasensitive if it only goes to 2 decimal places.

Strangely I contacted my Urologists office and told them the results and test type and they said that it was fine and I could keep using that same test as all they need to see is a less than sign in front of my number. Yet I read an ultrasensitive PSA greater than or equal to 0.01 is highly predictive of recurrence (combined with other pathological factors). Did my Urologists assistant make a mistake in their response? I thought he would want to see the 6-month kinetics between 6-week and 12-week post-op to at least the 3 decimal so he could see (a) if I was below 0.01 to begin with and (b) if my PSA moved up, by how much, even if it was under 0.02.

Then I started to think... I read somewhere that other things other than cancer can cause PSA to fluctuate as much as 0.01 to 0.02. Even women can have small amounts of PSA. So imagine the potential anxiety you cause a patient when they see their PSA bouncing around over the years between 0.005 and 0.015 using ultrasensitive tests when that could just be non-PCa related fluctuations and nothing to worry about. Combine this with the fact no Urologist/Oncologist is going to start even discussing salvage treatment planning until you probably hit 0.04. And the studies are all over the map on cut off for predicting chance of recurrence (0.03, 0.02, 0.01, 0.008 as I mentioned before). My own opinion is that 0.02 is a good level with high confidence.

I had a great post-op pathology report. No Gleason upgrade (still 3+4 with about 15% grade 4), no positive margins, no seminal vesicle or lymph node invasion. So my PSA result of less than 0.02 combined with my other factors, I still statistically have a low chance of recurrence. Definitely if I get an ultrasensitive next time around I will be interested if it is below 0.01. After that I really don't want to know my score unless it hits 0.02. Fluctuations under that just have the potential to cause me undue stress possibly caused by things not having to do with PCa progression.

Is there much utility though to an Ultrasensitive test when you otherwise have good Pathology results?

[Tall_Allen]

3 consecutive increases below 0.1 are a good indication for early salvage according to RADICALS-RT, but that was only with a positive margin. If your pathology results were all good, I can't think of any reason to get ultrasensitive PSA:

prostatecancer.news/2021/10...

[jazj in reply to Tall_Allen]

Me either. I have since confirmed that I did indeed get an ultrasensitive test. The regular test's lowest reading is < 0.1 not < 0.02. Each lab can have a different cutoff. Some may have a < 0.01 cutoff some may show more decimals. Based on the fact PSA can fluctuate 0.01-0.02 and having nothing to do with Prostate Cancer, I would prefer to not see results beyond two decimals, especially while under 0.02.

[allie2020]

I had my RP about four years ago. I have always gotten my uPSA tests at the same lab and they are sent to Sonora Quest. The least their equipment can measure here is 0.03 and my results have always been <0.03. I could easily have my samples sent to Lab Corp and get the results to the thousandths (3 decimal places) but I choose not to. I have another uPSA test coming up soon and always feel some anxiety. It's OK, my girlfriend and I always celebrate nicely when it comes back undetectable. Insurance pays fully for the ultrasensitive tests.

[Justfor_]

Ultrasensitive is indiscriminately used for anything else than single decimal PSA notation. Absolute PSA value is not important. Its kinetics, like velocity or doubling time (PSADT), ARE. To get a somewhat reliable PSADT you will need 5-6 monotonously ascending PSA registered values (anything with a preceding "<" should be discarded). A 3 decimals time series will give you an earlier warning, but IMO not a necessity.

In the absence of a reliable PSADT and 2 decimals denominated labs, my personal road map would be:

0.03 -> 0.04 start worrying

0.06-> 0.07 start discussions regarding next therapy

0.09 -> 0.10 PSMA PET/CT before anything else

Until then relax, you are doing great!