Re: Accuracy of sensitive PSA tests

[Guest guest]

Hello , Your question could likely be better answered by the two primary laboratories used to determine PSA and other blood serum levels, either Quest Labs http://www.questdiagnostics.com/home/contact/customer-service.html or LabCorps http://www.zoomerang.com/Survey/WEB22EBMX43GNP/. Pose the question to Customer Service as to the equipment they employ to determine PSA levels and the accuracy of that equipment. Let us know what you learn. Chuck Always as close as the other end of your computer to help address any prostate cancer concerns. " What you leave behind is not what is engraved in stone monuments, but what is woven into the lives of others. " (Chuck) Maack - Rmd, PCaA, PCaM Email: maack1@... PCa Help: " Observations " http://www.theprostateadvocate.com From: ProstateCancerSupport [mailto:ProstateCancerSupport ] On Behalf Of Sent: Monday, July 23, 2012 9:44 AMTo: ProstateCancerSupport Subject: " Accuracy " of sensitive PSA tests Apropo of the current Question thread and my own experience, I thought it would be worthwhile to start a discussion about the accuracy of current PSA tests.Firstly, don't confuse resolution with accuracy. Cheap digital voltmeters often have two digits of resolution to the right of the decimal place at low voltages. So if you read 0.05 volt can you expect that the real voltage is 0.05 +/- 0.01? No, it is probably more like something between 0 and 0.1.So is the same thing true of PSA tests? I recently received a PSA result from a new lab of 0.13 whereas the old lab had reported < 0.1 for five years post RP.Can a lab test have a real accuracy of 0.01 ng/ml when it has to cover a range from 0.01 to 100 or more? Is a reading of 0.13 accurate within +/-.01 ng/ml. Or is the PSA test just like the cheap digital voltmeter- it implies a false accuracy because it has a lot of digits to the right of the decimal point?No virus found in this message.Checked by AVG - www.avg.comVersion: 2012.0.2197 / Virus Database: 2437/5149 - Release Date: 07/23/12

[Guest guest]

Chuck:

Thanks for the links. I sent them the question and will post any response that I

receive.

[Guest guest]

, This subject was discussed at some

length on another Forum. I summarized the discussion at http://www.yananow.org/UltraPSA.shtml

Hope you find that of some interest

All the best

Prostate men need enlightening, not

frightening

Terry Herbert - diagnosed in 1996 and

still going strong

Read A Strange Place for unbiased information at http://www.yananow.org/StrangePlace/index.html

From:

ProstateCancerSupport

[mailto:ProstateCancerSupport ] On Behalf Of

Sent: Tuesday, 24 July 2012 12:44

AM

To:

ProstateCancerSupport

Subject:

" Accuracy " of sensitive PSA tests

Apropo of the current Question thread and my own

experience, I thought it would be worthwhile to start a discussion about the

accuracy of current PSA tests.

Firstly, don't confuse resolution with accuracy. Cheap digital voltmeters often

have two digits of resolution to the right of the decimal place at low

voltages. So if you read 0.05 volt can you expect that the real voltage is 0.05

+/- 0.01? No, it is probably more like something between 0 and 0.1.

So is the same thing true of PSA tests? I recently received a PSA result from a

new lab of 0.13 whereas the old lab had reported < 0.1 for five years post

RP.

Can a lab test have a real accuracy of 0.01 ng/ml when it has to cover a range

from 0.01 to 100 or more? Is a reading of 0.13 accurate within +/-.01 ng/ml. Or

is the PSA test just like the cheap digital voltmeter- it implies a false

accuracy because it has a lot of digits to the right of the decimal point?

[Guest guest]

--Something I've wondered about too. Never could find any real info on the

testing - or results either. My PSA was <.05 for several years after surgery,

then at another hospital I was getting .06, .07, then .05 last. How accurate

can it be at those levels? Let us know what, if anything, you find out.