I was wondering: i thought that when you get below the 10% pcr you must be in a MCyR. I was below 10% in various tests since my 6 months, but my marrow was at 40% PH+. Is this possible? is it possible a mistake in the cytogenetic test? I'm probably moving to tasigna 800 mg in the next few weeks. Thanks in advance!
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pcr < 10% and not in MCyR. is it possible?
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Hi Lucas,
CML is concentrated in your marrow and so it will always give you a higher rate compared to a blood test. You can only compare your BMBs to your BMBs and your blood tests to your blood tests. I only had two BMBs so when I was/am following my results they are based upon my blood test results.
Thanks for the insight gerry, but i was about the relation between pcr and cytogenetics. like: if you have a less than 10% pcr, it correlates with 35% or less ph+ cells in the marrow. one of my doctors was thinking about a re-test, but i preferred to change medications. i'm one week into tasigna and so far so good.
cheers!
Hi Lucas,
I am not sure that your example is right. It is my understanding that at the 3 months mark, to be on track with the ELNet recommendations for an optimal response you need to have either less than 10% BCR-ABL1 by PCR
OR less than
35% PH positive cells by cytogenetics/FISH.
I don't think this means that 10% by PCR correlates to 35% Ph+ivity.
The problem with PCR testing is the sensitivity of the methodology used in a particular lab. If you have a PCR result of <10% from a blood sample then it should, more or less, be reflected in cytogenetics testing taken from a sample in the marrow- if there is a discrepancy between the two kinds of tests then further investigation or a retest would be necessary.
I think you did right to change TKI. I hope you do well with nilotinib and your next PCR test shows a drop in BCR-ABL1.... ;o)
Sandy
thanks, sandy.
I actually did a retest. i was 6.8% IS at 6 months from my local lab. my 7 month pcr - from that same lab (only 7.500 samples of the control gene) -was 2.9% IS (it seems a big drop for less than one month, what made me think it was not a reliable result). 10 days after i went to the best lab in country -they use more samples of the control gene (200.000), another control gene and another method, etc. etc. - and the result was 6% (so it was into the error margin of the test and less than the 6 month's pcr). Somehow my pcr is less than 10% but i have a large number of PH+ cells in my marrow (a friend of mine said that the lab that runs my cytogenetics belongs to novartis, but i don't think that's the case). I know that the BMA is more accurate and even if it was a mistake (i heard about some people who had a MMR but because a blip had one ph+ cell in the bma and than it dissapear) i think i did right changing my treatment. I think i'll get much better results now and i'm feeling ok with tasigna :)
Hi Lucas,
Thought you were comparing BMB results with your blood tests.
OBJECTIVE: To compare the sensitivity and specificity of Real Time Polymerase Chain Reaction (RT-PCR) with conventional cytogenetics in diagnosis of chronic myeloid leukemia.
http://www.ncbi.nlm.nih.gov/pubmed/24613116
Good luck with Tasigna.
Thanks, gerry! The paper you send me talk about pcr x cytogenetics at diagnosis. i don't know if we can apply this after DX. As you can see, all my results were less than 10%, even the test i had in the most sensitive lab in brazil (i know a guy who is pcru in every lab but when he had tests in this particular lab his pcr runs abou MR4, mr4.5). Well, i'm on tasigna. it's gonna work :)
Cheers!
unfortunately not many labs run pcr tests with this profile. i think i'll use this most sensitive lab for a long time. it's far from my city (3 hours by plane), but i think that's the only way i can get reliable results. there's a lab in other city that runs the test with only 2.000 samples of the control gene. not many options. I live in a cit with 3 million people and none pcr machine. all my test are send to a city far away from here. Thanks again, sandy. you're greeeeat!