10 replies to this topic

[Gail's]

I am feeling confused and frustrated. I need to understand the difference in the bcr-abl test and the qpcr test. I've read Trey's intro to cml work, the nccn and cml society guidelines for CML monitoring and am confused. Please someone break down each test and how often and why they should be done.

My understanding was that bcr abl measures the presence of the gene for cml. Then I think the qpcr is the only way to measure log reductions. I had a bcr-abl test done for diagnosis, but never a qpcr. I asked the onc for a qpcr. Was told it would be done every 3.months to monitor progress. Since I didn't have a qpcr done at diagnosis, I wanted a baseline done. Looked up my lab orders and still no qpcr, just a repeat bcr-abl. Since I needed labs to be drawn yesterday, I called onc office and asked the covering onc to add the qpcr. When the dr was asked to do so, she replied that I was splitting hairs but she would order it to make me feel better. Pat, pat on my pretty little head. When I got to the lab, no qpcr ordered, just another bcr-abl. I'm mad and confused and more than irritated.

Is the bcr-abl going to be enough to accurately monitor my progress? If not, I need to be able to speak intelligently to dr next week.

[chriskuo]

I have only had and have only heard of people getting quantitative BCR-abl tests. I get the test every 3 months.
I have not seen anybody post here who did not get regular quantitative tests. Have you seen another doctor for a 2nd opinion yet?
As a minimum, you need to get to the point where you have confidence in the doctor treating you. That may require a 2nd opinion.

[Gail's]

I keep hearing that I should be changing dr. My problem is that, with the HMO I belong to, there is one oncology clinic so any dr I chose would be in the same practice. I looked into seeing Dr Druker since I live in the same area. I would need to pay out of pocket. He charges $540 for the initial visit then requires all of the labs to be re done using a specific lab, which would also be out of pocket.

[hannibellemo]

Gail,

 

Just to throw a wrench in, this early in the game I'd be asking for a FISH test. They are much more accurate at this stage then a PCR. I didn't have a PCR done (after the baseline) at Mayo until I'd reached CCyR.

[Tedsey]

I am feeling confused and frustrated. I need to understand the difference in the bcr-abl test and the qpcr test. I've read Trey's intro to cml work, the nccn and cml society guidelines for CML monitoring and am confused. Please someone break down each test and how often and why they should be done.

My understanding was that bcr abl measures the presence of the gene for cml. Then I think the qpcr is the only way to measure log reductions. I had a bcr-abl test done for diagnosis, but never a qpcr. I asked the onc for a qpcr. Was told it would be done every 3.months to monitor progress. Since I didn't have a qpcr done at diagnosis, I wanted a baseline done. Looked up my lab orders and still no qpcr, just a repeat bcr-abl. Since I needed labs to be drawn yesterday, I called onc office and asked the covering onc to add the qpcr. When the dr was asked to do so, she replied that I was splitting hairs but she would order it to make me feel better. Pat, pat on my pretty little head. When I got to the lab, no qpcr ordered, just another bcr-abl. I'm mad and confused and more than irritated.

Is the bcr-abl going to be enough to accurately monitor my progress? If not, I need to be able to speak intelligently to dr next week.

qpcr (or rt-pcr) is the machine that tests for the bcr-abl1 fusion protein at the molecular level (the "1" is often omitted from the abl when written about) .  It has been determined that a person should not have the bcr-abl1 fusion protein in their blood.  If they do, they have CML.  If you have just been dx, then Pat is right.  The PCR (molecular test) will not be as useful as a test that looks at your chromosomes (larger than molecules).  Chomosomes are looked at using a FISH test or by karyotyping.  When your FISH test (or karyotyping) is at 0, then pcr (or rpcr, a.k.a. bcr-abl1 testing) will be more useful.  However, most oncs will run both from the very beginning.  PCR (or bcr-abl) is used to determine residual disease over time and is most useful when the Ph+ chromosome can no longer be seen in a sample of your blood.  So, the first step is a negetive FISH in about 18 months after diagnosis.

[Gail's]

Thanks Tedsey. Very helpful. The FISH was done and came back 92% about a month ago. If I remember right. Makes sense to wait on pcr now. My latest CBC and diff came back completely normal!! So glad this is working so well!

[Trey]

PCR = QPCR, no difference.  There are 2 types of PCR: Quantitative and qualitative.  One has a number and one has only a "yes/no" positive for BCR-ABL (CML).  BCR-ABL test is PCR.  So several names for the same test.

 

Further reading:

http://community.lls...l=+cml +testing

Edited by Trey, 31 March 2015 - 08:20 PM.

[Gail's]

Thanks Trey. I reviewed labs with the NP today. She said they can't tell a log reduction from the bcr-abl because it's more of a yes/no test with undetectable being the goal. The number result on the report was a percentage. Mine went down from 37% to 15% in the past 2 months on gleevec. Not sure what the % represents! but the chief finding was that it was detectable so they will watch for undetectable to happen within the first year of treatment. If that doesn't happen she said they'd talk about different med.

[Pin]

It is all very confusing at first, but you will learn it soon enough. To make it harder, different doctors have their own ideas of what's best, and some aren't very good at explaining things to us.

Also, not all doctors will do a FISH test, mine didn't, they just used PCR testing from the beginning.

It's good that your percentage went down. In the beginning, Any progress downwards is the main thing that matters. There are benchmarks for when you should meet certain goals, this is in Trey's guide. If your tests are done on international scale (IS), which may be written on your results, then the benchmarks are roughly less than 1% is good, less than 0.1% is great, and less than 0.01% is excellent. Anything below that is a bonus.

I hope this doesn't add too much to the confusion, it is a lot to take in.

[Trey]

Gail,

The Onc may be doing both types of PCR, qualitative (positive/negative) and quantitative (% number). 

 

Ask if the % number is International Scale.  If so, then the starting point is assumed to be 100%, so CCyR (2 log reduction) is 1% and MMR (3 log reduction) is .1%

[Gail's]

Yeah, Trey, it is IS. The fish said 92% about two weeks into treatment but I understand it's a completely different measurement.