uPSA question

If it bugs you too much, I suppose you could pay out of pocket to repeat with a more sensitive test. Might be worth the cost to put your mind at ease.

My last Labcorp uPSA test also came back <0.014 two weeks ago. You and I had the same Labcorp uPSA test -- the problem is that, depending on the analyzer on which they run the (ROCHE) assay, there are two different lower limits of detection. In fact, <0.014 was Labcorp's lowest limit of detection until just a few years ago. (I'm not allowed to post the link, but a popular walk-in lab has a sample Labcorp uPSA test result with a copyright date of 2015 that they never bothered to updated. The result there is <0.014 and the test name and number are that for uPSA.)

Labcorp has only one uPSA test (with or without Serial Monitoring, the latter coming with a useless graph of all your values). Unfortunately, it appears to be hit or miss now which analyzer you get. I sent them a message through the portal, but haven't gotten a response. I think they are up to their neck in Covid-10 tests.

If you look at their Test Menu page for the uPSA, you'll see that Labcorp makes no claim about the lower limit of detection. If you have the test rerun, there is no guarantee you'll get the more sensitive analyzer (unless your doc can arrange it). Although my nadir was 0.007, my previous test result was 0.015 -- so I'm not that bothered by the recent <0.014 result. In fact, since my recent values have been slightly greater than 0.014, I don't know which analyzer they have been using!

A study was published in 2017 with the results found by an independent lab looking at the accuracy and precision of the ROCHE PSA assay that Labcorp uses. When they performing 20 repeat runs of a 0.010 ng/mL target PSA sample in ideal lab conditions, the authors found that two standard deviations (which encompasses 95% of results) was ± 0.002. So I would not worry about tiny fluctuations at very low PSA levels! There are many reasons fluctuations happen, some external, like the test itself, and some internal, to your body. For example, here are my values

11-28-17 (3 m ) 0.010
02-26-18 (6 m ) 0.009
05-30-18 (9 m ) 0.007 (nadir)
08-27-18 (1 yr.) 0.018 (huh?)
09-26-18 (13 m) 0.013 (retest)
11-26-18 (15 m) 0.012
02-25-19 (18 m) 0.015
05-22-19 (21 m) 0.015
08-28-19 (2 yr. ) 0.016
12-18-19 (28 m) 0.015
06-30-20 (34 m) <0.014

Best,

Djin

GG, I'd be interested to know the discussions regarding your decision for adjuvant RT (with your G6 with tertiary pattern 4, SVI+, ECE+, and high Decipher score) as opposed waiting and doing adjuvant or very early salvage only if and when your PSA showed signs of rising. How insistent were your docs and did you need much convincing?

Thanks,

Djin[img]

Even when certain adverse features, viz. SVI+ and/or EPE+ are found after surgery --- in other words there was locally advanced PCa -- it is still possible that the RP removed all the cancer. Nor does locally advanced cancer necessarily have to be metastatic or have metastatic potential -- however, your Decipher results quashed that hope. It was my hunch that with your uncommon path status, your docs left the adjuvant-now-or-wait decision to you. Hats off for being proactive!

Djin

Exactly same deal as FrackMe. I saw the LabCorp machine switch from <.006 to <.014 in 2013, which was my first year after surgery. From 2013 to early 2017, I was showing as <.014.

Then, Feb. 2017, started seeing readings anywhere between .024 and .050. Last month, it was .035.

All I can surmise is my one + margin, rated by Epstein at 3+3=6, is still putting out a little, but not growing much. I may die with this disease, not from it, and that's ok by me at this point. Lots of other things to worry about.

Robert