New Tumor Markers Test Method
 

Hi Everyone -
I got my labs last week from earlier in the month and there was a big asterisk in the boxes containing my CA 27-29 and CEA (Carcinoembryonic antigen) tumor marker results.

CA 27-29 says "by Bayer Centaur. NOTE: New test method effective 12/01/2006" The result is the same as I usually have with the old (Tosoh) method (same reference range).

CEA says more: *By Bayer Centaur *NOTE New Test Method effective 12/01/06. The Bayer Centaur method results are approximately 50% of those obtained by the previous Tosoh method. NOTE New Reference Range effective 12/01/06. Bayer Centaur CEA Reference Range: [0.0 - 0.2 Normal] [2.1 - 4.0] Indeterminate] [ >4.0 Abnormal]

I am mentioning this as the new CEA number may indicate a rising CEA for me if this really does not correlate to the old method. The lab at the U of W would not give me any information as they are not supposed to speak with patients. My onc is on holiday and all the oncs were supposedly given an info packet on this according to the woman in the lab.

Just wondering if this new test method is "out there" for any of the rest of you, and what you may know about it if you have been using tumor markers as a guide during your treatment or measuring NED (like I have).

Hi Steph,

I don't have an answer for you, but congratulations on the sharp lookout.

nice catch!

Hope the New Year brings the best.

My Med Onc's Reply
 

Gee - Even on a Sunday afternoon before New Year's Eve!
Here is what she says:

"We will need to follow the new tests for a while to "reset" a patient's baseline. Although the averages for large groups of patients are about the same for the new CA27.29 test, and about 1/2-2/3 the previous value for the new CEA test, some people's numbers will go up and some will go down. The tests are not meant to be sensitive or specific enough to detect significant changes within the normal range, so even if your CEA fluctuated between 0-4, we would not react."

I would think that if my CEA has been steadily below 1 and heads up toward 4 in a relatively short time, I would be seeking a reaction! This is not the case as it is still low with the new test.

My concern comes as my brain mets seems to make CEA a good marker indicating tumor activity or not. In any event my markers are drawn with every Herceptin tretment and I will have the new pattern established soon.

Hi
 

Dear Stephn: I have nothing to add regarding the new method as I will get my test done in a week, but I just wanted to say that I really love your new picture!!!

Have a Happy and Healthy 2007.

I love the new photo, too, Steph! You look great! And thanks for giving us a heads-up on the markers tests. Have a wonderful new year! Hugs, Tricia

Stephn,
If you get a look at the following study comparing test methods for various markers you surely will be surprised as I was by some of the wide variations in a number of test results:
http://www.wadsworth.org/labcert/cle...evaluation.pdf

To me this means that in those cases the markers should always be tested by the same process & that they are only valid as trend indicators if they move up or down but are not good indicators of the absolute status of the disease especially if they are relatively stable & not far off normal values.
A case in point I am personaly aware of regarding CEA is when it failed to predict or confirm a primary reccurence of a 3 cm tumour by staying around 5 to 6 for over a year as it was growing.
Some members of the Forum have reported the reluctance of their onc to rely on markers prefering clinical symptom, biopsies,X-Rays or scans.
I have even met an MD (not an onc) who is himself a cancer patient & who completely disregards CEA as valid marker.
I think he may be going a bit overboard but he is not totaly wrong.
The fact that blood tests are fast, relatively inexpensive & non invasive accounts for their usage.