PSA Screens Confusing Me

A new lab tech stepped in...stopped the practice of reporting 0.0 on 1 decimal point test{impossible )...an implied function...used the more correct for 1 decimal point test of 0.1...made his own implied function by omitting the< less than...this became self evident with the 2 and 3 decimal point test...to your last question.the .04 imo...you can ask the oncologist with phone consultation or make apt to see the person..do not ask the nurse or receptionist...they are notoriously uninformed on psa testing and how itaffects post op surgery patients and their treatment... BY implied function I'm mean they use what they think they know about the importance of data right before their eyes...make an ignorant assesement of the value of that data to the patient...and think to themselves " what a good boy am I "...this all from a tech...not a medico...hey this is my guess...I could be totaly wrong...caveat emptor

Same story: I've been tested every six months using Quest Labs for 5 years post-prostatectomy, with their results (using Beckman Coulter DxI) always given as < 0.02, which Quest says is the lower limit of the test, i.e. "undetectable."

Yesterday my urologist repeated the test using Eisenhower Hospital's lab for comparison. They are currently comparing the results of two systems, Siemens Centaur and Beckman Coulter DxI. He explained that they are trying to validate the two systems.

My results from Eisenhower were 0.05 with Centaur and 0.010 with DxI (which I believe is the same equipment as used by Quest, but there could be some difference). So there seems to be a lack of clarity on lower limits of sensitivity with these tests, with variability due to lab technique and patient specifics. Is Quest more conservative than Eisenhower in refusing to report down to 0.001 ng/ml?

' if you build it...they will come'...much like the obstruction the navy built adjacent to the flight path at a navel air station...to accommodate an spare obstruction light found in inventory...of course an instructive parable...the fact that many of you would not be surprised...if it were true...prompts me to say...mythology really is truer than truth in the sense that it reveals...hidden truths...unrevealed in create-ures so called truths... Hey as the comic said as he was wagging his cigar..."I got a million of em" Ok I'm sighing off...me brain is fried...

Of course it's commercialism--and the researchers don't help when they tell people they should seek salvage treatment at 0.02 or something. That assumes everyone has access to the lowest range tests--and that those tests are being run correctly, every time.

There is a HUGE difference between what can be achieved in a research lab and what can be done on a daily basis in a doctor's office or commercial lab that runs hundreds of samples a day.

My two cents is that the lab has validated a new instrument and is reporting values from both instruments to allow the physician to compare both values before retiring the older instrument.
This is assuming you are talking about two results from the same lab. If not, my bad.

FWIW, my experience with the Centaur is that it rarely reports values less than 0.01.
When I had my first post-op PSA the Centaur (the older instrument) reported 0.05 and the COBAS (our newly validated instrument) <0.006.

Laboratories use different standards to set their lower limits. The may use the limit of the blank, the limit of detection, the functional sensitivity, or another value they determine to be significant. For the COBAS these would be <0.006, 0.014, and 0.030.

I had my prostate removed by Da Vinci method February this year 2018 my first PSA result was 0.004 is that good I have not had any reports with all the data probably have to ask the Doctor for a copy.
My Gleason was 3 + 4
My PSA originally was 24.
All core samples were positive both sides of the prostate were cancerous and I also had cancer out side the prostate.
22 Lymph nodes removed all ne
Vesicles Neg Viens Neg Tc3 positive margin on the bladder neck but the PSA has not been explained as I work away and have not had the chance to speak to anyone thanks.