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Posted 8/11/2020 1:42 PM (GMT 0)
Good morning everyone. As you can see from my profile, I had a RALP back in January of 2017. I've tested at <.006 at LabCorp now for a little over three years. My most recent test there on 8/10/20 came back as <.014. Does anyone know if they changed their testing range? I know it's a bit silly but this has got me quite anxious, maybe the < is an error and I'm actually .014, etc. You know how we get. Anyway hope to hear from some of you, be well.
Posted 8/11/2020 3:11 PM (GMT 0)
This also happened to me for the first time at my last test. BTW, your signature isn't showing.

There is just one Labcorp ultrasensitive test; however, they run it on different model analyzers, which have two different lower limits of detection. One is 0.006, the other is 0.014. So if you get the first model and your PSA is lower, it will come back as <0.006; on the other model a lower PSA will come back <0.014. The Labcorp <0.006 models have been around just a few years, I believe.

If you look at the test menu at the Labcorp website and look up their uPSA test, you'll see that (like most tests) they do not state the lower limit of detection. You know it only if your result has the < sign in front of a number.

In your case, you lost a bit of information. In theory your PSA could have increased a bit, because you don't know if it's still <0.006 -- but I doubt it. If you get the more sensitive analyzer next time, you'll know smile

I think Labcorp is up to their necks in Covid-19 testing!

As the Brits say -- Not to worry!

Djin
Posted 8/11/2020 3:12 PM (GMT 0)
Labcorp uses 2 diffrent assays, with two different detection limits. Nothing to worry about, you are good. I dont know what determines the assay they use in each test, maybe going forward your Dr can request the one with the lower limit of detection. Not sure the name of each, but i'm sure its easy enough to find out, on their website, although someone here may chime in with that info (Djin?)
Posted 8/11/2020 3:17 PM (GMT 0)
I guess one's doc could call Labcorp, and either redraw and retest now, or call ahead next time. Seems like too much effort for too little to rerun the test -- and I think they would charge because no error was made on their part..

I have my blood drawn at my uro's office. Next time I'll as the tech if she can please write "Please run on analyzer that tests to <0.006" on the form. Who knows?

Djin

Post Edited (DjinTonic) : 8/11/2020 9:24:07 AM (GMT-6)

Posted 8/11/2020 4:25 PM (GMT 0)
One is <0.006, the other is <0.014.....a difference without a distinction. LabCorp resources are invested in C-19 testing. Go enjoy life, Crusher.
Posted 8/11/2020 4:32 PM (GMT 0)
Thanks everyone, you've put my mind at ease. I wasn't too worried, as I figured <.014 really is the same as <.006 in that they're both considered undetectable. It was just a bit of a shock after three years of <.006.

Ahh I see I forgot to check Include signature....
Posted 8/11/2020 5:14 PM (GMT 0)
In addition to the best possible RP path outcome (G6 + pT2 with no positive margins), your PSA nadir of <0.006 augurs a low risk of future BCR according to studies estimating BCR risk from one's post-RP PSA nadir. Congrats!

To Pratoman's point, the assay used by Lacorp's uPSA test is a the same ROCHE immunoassay in both cases. What differs is the model analyzer used to measure the results. To give an analogy, take a colorimetric assay for a substance that yields a solution whose color is more intense the greater the concentration of substance. Analyzer model A may be able to detect and quantify fainter colors than model B, making it able to measure down to a smaller concentration. The assay (biochemical test) is the same however. Just an analogy -- I don't think this PSA assay is colorimetric.

Djin
Posted 8/11/2020 8:38 PM (GMT 0)

DjinTonic said...
In addition to the best possible RP path outcome (G6 + pT2 with no positive margins), your PSA nadir of <0.006 augurs a low risk of future BCR according to studies estimating BCR risk from one's post-RP PSA nadir. Congrats!

To Pratoman's point, the assay used by Lacorp's uPSA test is a the same ROCHE immunoassay in both cases. What differs is the model analyzer used to measure the results. To give an analogy, take a colorimetric assay for a substance that yields a solution whose color is more intense the greater the concentration of substance. Analyzer model A may be able to detect and quantify fainter colors than model B, making it able to measure down to a smaller concentration. The assay (biochemical test) is the same however. Just an analogy -- I don't think this PSA assay is colorimetric.

Djin

The comparison with color intensity is an elegant analogy. Many laboratory tests have moved on from simple colorimetry to more sophisticated testing methods. Some of the old tests, like creatinine and Blood Urea Nitrogen (BUN) still use colorimetry.

I was a medical laboratory scientist by trade. We had an incident many years ago where an old bottle of picric acid, used for creatinine testing, was forgotten in storage. When picric acid dries, it is an explosive. Once the old bottle was discovered, the bomb squad was called to safely remove it, and the nearby Emergency Department at the hospital had to be evacuated.
Posted 8/12/2020 10:59 AM (GMT 0)
Tim, that's funny....in a morbid sort of way. Calling a bomb squad to get rid of a vial of picric acid. I, too, am an analytical chemist--with a specialty in the really arcane field of ultrapure water. We use colorimetry every day.

I've attempted more than one on this forum to explain the difference between precision and accuracy, and the meaning of detection limit and limit of precision. Personally, I think results should be reported as the number with the +/- precision value added. I know, it would be confusing and upset a lot of people--but--it would be the true correct report.

Anyway, to the OP: not to worry. As long as you have the <, you're good. Carry on.
Posted 8/12/2020 2:26 PM (GMT 0)

halbert said...
Tim, that's funny....in a morbid sort of way. Calling a bomb squad to get rid of a vial of picric acid. I, too, am an analytical chemist--with a specialty in the really arcane field of ultrapure water. We use colorimetry every day.

I've attempted more than one on this forum to explain the difference between precision and accuracy, and the meaning of detection limit and limit of precision. Personally, I think results should be reported as the number with the +/- precision value added. I know, it would be confusing and upset a lot of people--but--it would be the true correct report.

Anyway, to the OP: not to worry. As long as you have the <, you're good. Carry on.

When I've had to explain it I used that classic diagram of 4 targets with bullet holes:

Holes tightly grouped in bullseye: gun accurate & precise
Holes tightly grouped outside bullseye: gun not accurate but precise
Holes poorly grouped in bullseye: gun accurate but not precise
Holes poorly grouped outside bullseye: gun neither accurate nor precise

Then you go on to give examples of the combos with a digital scale and a known weight.

The confusion of course comes from the non-scientific precise meaning accuracy of expression or detail.

Djin
Posted 8/12/2020 4:28 PM (GMT 0)
Djin, speaking of Labcorp, I am in the process of switching to them, and switching urologists altogether for that matter. My uro group for the past three years does their own testing (it's a large practice with many docs and locations, so probably found it economical to do their own labs). My PSA has always come in at <.008 and my testosterone has been slowly increasing from 20 to most recently 60.

But I'm not real happy with anything about their operation. Sometimes they forget to run either the PSA or the T, then I need to get another blood draw. Sometimes they report my PSA as "zero" and I have to call them to get the true number. Of course there is always much bureaucratic office hassle required to get any of this accomplished.

I have acquired scripts for the next two blood draws (Jan & July 2021) and setup an online account at Labcorp. Their menu is somewhat overwhelming. I "guess" the codes I want to use are 140731 for uPSA (CPT 84153) and 004226 for total testosterone (CPT 84403). Correct? Or at least, as far as you know? I figure that my PSA is essentially meaningless until I see some substantial testosterone recovery, if that ever happens, unless I develop some sort of freak castrate resistance.

Thanks!
Posted 8/12/2020 5:36 PM (GMT 0)
Hi Roblee,

That is the correct uPSA code for the test "without serial monitoring".
The uPSA code for the same test "with serial monitoring": is 140723 CPT 84153

If they are the same price, you can order the one "with" -- it comes with a pretty useless graph of all the results that you've ordered with that code. If the graph version costs more and you are paying out of pocket, don't order it -- you do not need this graph! The Y-axis goes up to 20.0, so our very small uPSA values all lie along the X-axis.

When you say your previous numbers were <.008, was that with the blood drawn at your current uro? If so, I think they are sending it out to a Labcorp facility. My uro's practice also has in-house testing, but their PSA test, while also a Labcorp test -- goes down only to <0.05. (I have my blood drawn at my uro, but they send it out to Labcorp). I would be very surprised if your uro has that sophisticated an analyzer in their office!

As for Testosterone, I'd rather someone else help you out -- I've never had mine tested and don't want to lead you astray smile

Djin
Posted 8/12/2020 6:45 PM (GMT 0)
Rob....140731 for uPSA (CPT 84153) is what's on my LabCorp orders and I highlight it for them so they don't overlook it, which has happened in the past.

Can say for for sure, but I think a low uPSA is desirable, no matter what your T level is.
Posted 8/12/2020 7:31 PM (GMT 0)
Rob, re the testosterone.... First, your code is correct...i went back and checked the last time i ran the test at labcorp through Walkinlabs.com in Florida, and that is the code they used on the order.

Second, i cant swear to it, but i think you are mistaken and in fact your PSA DOES mea someting, even with the low PSA. I thought the same thing, when my T rose to 90, and the Nurse Practitioner corrected me, telling me that its above castrate levels and so even with the low T, it can affect the PSA. Also there has been some conversation about research that shows, once T reaches a certain (LOW) level about castrate level, the ADT is no longer keeping PSA down and any additional rise wont affect PSA any further. In other words, when T rises above, say 40 (not sure of the number) its the same effect of PCa as if it rose to 540.

I cant recall the name of the research but someone here may hopefully chime in.
Posted 8/13/2020 8:15 PM (GMT 0)
Thanks Ken (and Gary and Jared). Yes, I believe what you're thinking of is Dr Abraham Morgentaler's saturation theory. True, PCa can survive on just a little testosterone as well as a LOT of it (the example given is a potted plant). Note it has only been in 2020 that my T actually rose above castrate level, just as I had predicted back in the CFN days. So I don't mean to dismiss it.

Thanks for the codes.
Posted 8/13/2020 11:59 PM (GMT 0)
Yes, the saturation theory, that’s it.
Let’s just hope that PSA stays down
Posted 8/14/2020 1:40 PM (GMT 0)

Pratoman said...
Let’s just hope that PSA stays down

"Factoids" I've heard, read online, or been told by a doctor:

  • Average time to recurrence in otherwise NED patients is eight years
  • BCR has been known to appear as late as fifteen years of remission
  • Max-RP with R0/M0/N0 show the least likelihood of BCR of all PCa patients
... all of which are in my favor. Lucky me!

Though I still feel that we need a better term than "Max-RP" for (RP+HT+RT)
Posted 8/14/2020 7:07 PM (GMT 0)
The average time to reoccur, IIRC, is from 8 to 13 years, although never sounds better ;-)

Having PCa, but passing away from something/anything else probably screws up the statistics and averages more than the thousands of clerks reporting COVID-19 numbers do!
Posted 8/14/2020 7:22 PM (GMT 0)
Something sounds amiss in those BCR factoids. Here is what I noted down some time ago:
_______________________________________________________
One study found 75% of the high-risk men encountering BCR did so in within the first 2 years post-op and 82% within 3 years.

Another study: For all-risk men: 2/3 of men encountering BCR do so within the first 2 years.

One study of BCR prediction: for patients whose PSA was ≤0.04 (n=765) at 3 years, 95.7% were BCR-free at 7 years. The rate for the >0.04 men (n=36) was 65.4%.
__________________________________
Keep in mind that averages (means) can be quite misleading. For "average incomes," the small percentage of folks with extremely high incomes makes the mean non-representative. That's why the median is used for household incomes.The same, I would think for BCR: the late recurrences are less numerous, but skew the mean upwards.

Djin, who hit his 3-yr post-op mark last week.
Posted 8/15/2020 1:22 AM (GMT 0)

DjinTonic said...
One study found 75% of the high-risk men encountering BCR did so in within the first 2 years post-op and 82% within 3 years. Another study: For all-risk men: 2/3 of men encountering BCR do so within the first 2 years.

Djin, who hit his 3-yr post-op mark last week.


Just sayin', by stating "otherwise NED" would knock many of those two and three year fellows to the curb. And anyone who is high risk should be getting adjuvant therapy. And I'd guess that many guys who believe that they were in full remission for two years following primary therapy probably just had PSA's below the level of detection. Anyway, I was just throwing spaghetti at the wall.

Congrats on your three year mark. My four year anniversary is but two weeks away. At this time three years ago I was finally just getting ART underway, after a lengthy struggle with the Kegel coach and a couple of AUS surgeries.
Posted 8/15/2020 2:16 AM (GMT 0)
Thanks, RobLee!

I was and still remain high-risk by virtue of my definitive G9 (4+5) Gleason score following my RP. (A G score of 8 or higher alone suffices for a D'Amico high-risk qualification). However, if you look at treatment guidelines put out by major US or international organizations, no adjuvant treatment is recommended for me (nor was it by my uro/surgeon).

Treatment guidelines for my category (pT2 with no positive surgical margins, and no evidence of mets) do not advise adjuvant treatment (but of course salvage treatment would be necessary if BCR occurs in the future). I chose surgery banking on having caught my PCa very early and hoping to avoid RT and ADT and I'll be darned if I'll do either just for the glory if they are not SOC.

Djin
Posted 8/15/2020 1:58 PM (GMT 0)

DjinTonic said...
I chose surgery banking on having caught my PCa very early and hoping to avoid RT and ADT and I'll be darned if I'll do either just for the glory if they are not SOC.


Well, as I've mentioned elsewhere, you were "lucky"... though a dubious honor if one can ever say that anyone was lucky to have cancer. Let's just say, fortunate, that you persevered and your VHR aggressive tumor was detected and successfully treated in time. I'd say yours is likely an exceptional case, rather than one that is typically within statistical norms.

I too chose surgery for pretty much the same reasons. PCa appeared on MRI to be contained and I had a 50/50 chance of RP alone being curative. Didn't turn out that way. In that regard, I am like many other guys here on this forum who are more textbook examples... RP followed by HT and ART. But guys who were fortunate enough to have had once and done usually don't stick around.
Posted 8/15/2020 2:34 PM (GMT 0)
Was I lucky, yes. But I don't see why you think my outcome is "exceptional" if you think you had a 50/50 chance of RP being curative for your G8.

Djin
Posted 8/15/2020 8:23 PM (GMT 0)

DjinTonic said...
I don't see why you think my outcome is "exceptional" if you think you had a 50/50 chance of RP being curative for your G8.


Exceptional more due to the extraordinary steps and the number of biopsies that it took to find such a high grade tumor. I think I've read that the number of G9-10's are something like only five or ten percent of all cases. Also exceptional that it was still organ confined.
Posted 8/15/2020 9:10 PM (GMT 0)

RobLee said...

Exceptional more due to the extraordinary steps and the number of biopsies that it took to find such a high grade tumor. I think I've read that the number of G9-10's are something like only five or ten percent of all cases. Also exceptional that it was still organ confined.

If you do the math, it was extremely unlikely that my cancer was missed by more than the last few biopsies. Assuming for discussion that the chance of a biopsy retuning a false negative is about 1/3, when you multiple 1/3 × 1/3 x 1/3 .. you fast get down to very small chances that repeat biopies won't find an existing cancer. My path report estimated 5% of the whole prostate was involved by the cancer. That, coupled with my 6-month uro checkups, IMO suggests my cancer hadn't been around that long.

In other words my numerous biopies were not a hunt for cancer assumed to be there, as is sometimes the case. They were just due diligence to confirm that my slowly rising PSA was entirely from my BPH and not masking a PSA contribution from PCa.

Djin

Post Edited (DjinTonic) : 8/15/2020 3:26:38 PM (GMT-6)

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