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PCR Increase of 2800% following MMR4 - on Dasatanib


My first post, so hopefully someone is out there!

Having had a positive continuing downward trend on PCR ABL counts - since getting onto Dasatanib over just over a year my numbers had come down from 0.081% to 0.005% my latest results which cover a period of under 3 months since the 0.005% last result have gone up by some 2800% to 0.14%. Obviously this feels alarming. My consultant team have suggested a further test in 2 months time...

My questions:

Could this type of massive swing be a contaminated result or someone in a lab misplacing a decimal point ?

What does it mean if genuine and does anyone have experience in this regard - I assume it would show resistance/mutation to Dasatanib?

If the second point is more likely should I be pushing for a quicker next blood test given the order of magnitude in increase?


Answers/comments welcome!



Hi Rory,

I can relate to significant upticks. It is very stressful. Especially in the first year or two when I believe resistances are more likely to pop-up. At this point your numbers at 0.14% are still pretty low, so it would be difficult to test for mutations. In my own experience I have asked for a re-test to confirm the uptick was correct. I wonder if your oncologist would be willing to do that? Also, did you change labs recently? That can lead to pretty large variations in test results. I've also asked to do a more frequent test in the past (1.5 months) when I had an uptick. As these things generally change slowly, I think more frequent tests are more for your own sanity, but can be worth it if the oncologist is willing. 



Rory - I would ask for an immediate re-test. It is quite possible the results are due to lab error (it happens), but if it is not, you do not want to wait two months to confirm a dramatic upward trend as you reported.

I have a suspicion this is not real.

Guys - thanks so much for this input. I’ve no idea what size of magnitude you can see in outruns or downturns but of course am a bit sceptical about such a seemingly massive increase. 

if resistance is proven I assume I would then be out on posutanib? And without wishing to over dramatise does a two or three consecutive result rise upwards dictate an overall Likely decrease in life expectancy?

Thread continued from: 
18 months - PCR increase