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Meaning of the test?


Hello friends,

My boyfriend was diagnosed in May 2018 with CML, PH 100%, Bcr abl P210 positive. He is on imatinib 400. He has got his 6 months blood test as following:

Ph: negative

q BCR- ABL p210: negative ( which was positive 3 months ago). The test do not show the percentage like the pcr test people often talk about in this forum.

can anyone help me understand the meaning of the test. I can not wait till the day he is going to see his doctor (2 weeks from now)

the BCR - ABL p190: also negative in the 3 month test

Thank you so much!


It may well be a FISH test, rather than PCR

Have a read of our primer at the link above. Read up to page 8 and it'll describe CML testing and what a FISH test is. A negative result of a FISH test doesn't equate to a negative PCR, by the way. 


Thank you for sharing this link Mr David. Next time we will ask the doctor about FISH and PCR. We live in Viet Nam, a country in south east Asia.I find it hard to understand why the doctor did not use PCR test. Every test only showed negative/positive


I love Vietnam. I've been lucky enough to visit a couple of times - one of my very favourite places.

I may be wrong, but this is my guess as to what is happening:

PCR tests are excellent at identifying CML in tiny amounts. It can see the needle in the haystack. It's not so useful when there is lots of CML in the body. 

FISH is good when the is lots of CML. So it's very useful in the months after diagnosis, but usually not so useful in the long term. 

I studied the doctor wants to see a negative FISH result, which would indicate the medication is working, before moving to PCR tests. A negative FISH test usually equates to (about) a 1% PCR at the highest. 

Why isn't the doctor ordering the PCR test earlier? They are more expensive, so may wait to use PCR until it is the most useful testing tool.

This is just all speculation. 


Hi David

So lovely to hear your thought about VietNam I wish to have a chance to see you in my country. 

Your writing did help me understand more, and I think it makes sense as my boyfriend has been on treatment only 6 months.(although we hope the test is PCR negative, but in that case it is one in a million, isn't it?)

I will update more after seeing his doctor on Jan 17th

Thank you so much for all the infomation and support.




It would be very surprising, but not totally impossible, if his PCR test was negative. Most of us, many years later, still have positive PCR tests with low levels and that is absolutely fine.

The quality of the lab performing the PCR test also factors in to the result of the test. One lab that is not so good might report a blood sample as negative, whereas a high quality lab may be able to see very low levels of CML.