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Chromosome Testing


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#1 pammartin

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Posted 09 August 2012 - 05:47 PM

I had posted a few weeks ago I have maintained my PCRU and my BMB has no CML cells noted on the ones they examined, but I have a question.   I revisited Cleveland today and received the chromosome testing and the oncologist states it does not have the PH+ chromosome.  I was under the impression we always have the PH+ chromosome and it would show up in any chromosome testing.  Is this like the PCR test which only goes to .001% and there are still detectable cells if one tested further, or for now am I PH+ chromosome free for the moment.

I am only curious, this does not mean I am going to stop the med, lower the dose, or take supplements, it is working and I am not interested in changing anything at this point.  But of course after I am home, the mind wonders.

The doctor stated I have achieved cytogenetic response, an excellent milestone in 10 months of treatment.  I was thinking I had achieved that after the PCR test and the BMB came back clean before the chromosome test results were in.  I am confused once again about what is considered response and the different milestones.  I will have to read up on Trey's info again. 

I am to see her in three months and if this PCR test that was completed today is good, I will only visit Cleveland once or twice a year and follow up with local oncologist for 3 month visits.

Drinks are on me!



#2 GerryL

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Posted 09 August 2012 - 06:02 PM

I'm confused too, why is he stating that you have achieved CCyR if your PCR test is saying undetectable? One would thing you would be long past caring if you were CCyR as it is a milestone on the way to PCRU.



#3 pammartin

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Posted 09 August 2012 - 06:18 PM

I had my husband write everything down.  I forget faster than I am told.  That is why I was confused also.  She wrote down three milestones and darned if I didn't leave the paper laying on the exam table. 



#4 Trey

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Posted 09 August 2012 - 06:45 PM

The "chromosome testing" you refer to is the BMB cytogenetics test, where they look at white blood cells taken from the pelvis under a microscope, randomly select 20 dividing WBCs so the chromosomes can be seen, and look for abnormalities.  If all 20 are normal, then no leukemic cells were found, and the BMB report says 0 of 20 are abnormal.  This is CCyR.  The sensitivity of this test is low due to the sample size, so it does not mean you have no leukemic cells.  Your PCR was undetectable (PCRU), so it also found no leukemic cells in the sample, although its detection sensitivity is also limited (about 1 in a million at best).  So you are CHR, CCyR, MMR, and PCRU (the 4 milestones, although Oncs may not list the PCRU).  All PCRU is also MMR, CCyR, and CHR by definition.  But at initial PCRU, the patient can still have as many as 1 million leukemic cells, although testing cannot detect them at that "low level".  But a person has about 1 trillion blood cells in the body.



#5 pammartin

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Posted 09 August 2012 - 08:18 PM

Trey,

Thank you, I have been reading your posting for newbies on this subject, and with the above version I understand and am happy to be where I am with treatment.  As long as I stay below the detection level, I am not going to worry about it, and having a hospital where I can relax and allow them to treat me without second guessing every step is worth more than I could write.  I will always have CML, but at least for now the detection level is hanging out below.  Now I need to just sit back and relax for a few years until I can start bugging them about reducing the dosage to 70 mg.



#6 Tedsey

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Posted 09 August 2012 - 11:29 PM

Trey, I have some questions about FISH and karyotyping.  I have never had a FISH test done, only karyotyping from a BMB.  I achieved CCyR at 1 year (9 months on Gleevec and 3 months on Sprycel).  If I were to have a FISH test now, would it show PH+ cells (i.e. test looks at greater number of cells)?  I don't know much about FISH at all.  Logically, I would assume that CCyR would be a certain percentage of PH+ found instead of just 0.  Right?  I mean, we all have PH+ cells somewhere if the disease is detectable by PCR.  Anyway, I am still 2 logs below my first reliable PCR (6 months, 13.739 LabCorp NJ scale).  I think 2 logs is CCyR also and that and karyotyping is what my oncs ever looked at.   I was told by first onc, my numbers were not moving, so that 6 month number is probably close to what I was at dx (to clarify, my 6 mo. PCR was ordered by different onc and done at a different lab).

Sorry Pam to hijack your post!  Glad to hear you are doing so well!

Tedsey



#7 pammartin

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Posted 10 August 2012 - 09:07 AM

Hi Tedsey,

You hijack all you want.  All of our questions concern this darned disease and in one way or another we have all wondered or asked them to ourselves or on here.  Have a great day!



#8 Trey

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Posted 10 August 2012 - 09:14 AM

Teds,

The BMB cytogenetics test looks at 20 cells and the FISH looks at 200 - 500 depending on the type.  But that difference is statistically insignificant given that there are millions of blood cells in the samples taken during either a blood draw or BMB/BMA aspiration.  So no big deal.  BMB and FISH should be fairly consistent.  If you had a FISH done it would almost certainly be negative.  CCyR is negative BMB cytogenetics or negative FISH.  Most Oncs prefer to rely on the BMB as the gold standard for CCyR. 

An important issue is that you cannot use a post-diagnosis PCR as the starting point for log reductions.  After a patient starts TKI drugs, the starting point is wiped out.  So you say that your first reliable PCR done at 6 months post-diagnosis was 13.739, and you are 2 logs below that, but that is irrelevant, regardless of that "numbers not moving" statement which was  inaccurate since you had a significant WBC drop.  You could easily be 3 logs below diagnosis levels.  You are probably doing far better than you believe you are.  So instead of watching Madame Butterfly tonight you might watch The Sound of Music.  You are more like Maria than Cio-Cio.



#9 Tedsey

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Posted 10 August 2012 - 06:29 PM

Trey, you always make me laugh.  Thanks for the comparison.  My onc does not consider me MMR, but since I had no reliable PCR until 6 months, maybe I really am MMR.  Who knows?  In the beginning WBC (and everything else) dropped so quickly and dramatically with Hydroxyurea and Gleevec.  I didn't think of that.  My PCR had to move at least a little. 

"The hills are alive..." and so forth and so on." 

Teds

P.S. Maria just happens to be my birth name (but it was changed when I was adopted). 






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