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Small rise in PCR ABL test

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Quick question to the group - I have been taking 100mg of sprycel for the past 18 months. I have always had a downward trend in my PCR ABL number. In May I got my MMR and believe my number was .08 this past July. I just had my 3 month check up and the number was .18. My doctor wants to see me back in 1 month to retest. If the number has not gone down she would like to test for mutations.

My doctor told me that she has seen other patients numbers fluctuate and that this is a small bump, but she is being cautious. I can’t help but think this could be a margin of error with the lab or simply a blip in the big picture. I’m also very nervous about it.

Has anyone in the group had an experience like this? If so, what was your outcome?

Your last two qPCR values, 0.08% and 0.18%, are not significantly different based on the error of the method (typically taken to be around +/- 0.5 log).  These numerical blips occur frequently. In my 4 years of CML this has happened 3 or 4 times. Having said that the cautious retesting in 1 month is fine just to be sure the bcr-abl remains under control.  One other point, if your retest remains around 0.1% a mutation analysis may be difficult to accomplish based on the low level of available RNA.  Typically the point mutation test requires around 1% or more of bcr-abl transcipt.

Thanks for sharing your experience with this! It’s so stressful! Are you a sprycel patient as well?

Okay - I have an update my original thread. It bothered me that I did not have my exact numbers. Just spoke with my nurse and this is my trend over my last 3 appointments:

4/29 - 0.056

7/23 - 0.046

10/7 - 0.196

Is this cause for concern? Have others here had this experience? As the days go on I am becoming more and more stressed about this.

That is a loss of MMR, so your doctor is doing the right thing. They are also not overreacting as it could just be a very short term blip in your results - which were perfectly good before.

So while I can’t say you shouldn’t be concerned at all, there’s every chance this is just a temporary blip and if not there are other TKIs available. My money is on the former though, and the re-test in a month’s time will give you the desired result.

I would also ask, at the next opportunity, whether those results are on the International Scale or not.

Keep us updated.

David.

Thanks! I keep telling my self that this is just a blip on the radar and how 1 year ago I would have been thrilled with the result I got last week.

The numbers I provided are not on the international scale. 

Ok so your results are not IS values.  What testing laboratory are you using and have all of your results been collected at that same laboratory? And what was your starting (at diagnosis) qPCR value?  Even though they are not IS values you can still calculate your relative log reduction.  Assuming your results are collected at the same laboratory the roughly 4-fold change in your last two test results is not that quantitatively different.  I agree with David that this is most likely a routine blip.

The numbers I provided are not on the international scale.

In that case, it's hard to say if you have actually lost MMR or not. Do you know if your lab has a IS conversion factor? If not, that's the next question!

David.

You guys are going to love this - I have international scale numbers for the tests I did on 4/29 (0.056) and 7/22 (0.046). When I spoke to the nurse they said they DID NOT have the international scale number for my test on 10/7 and they only gave me the number .196. 

At the start of my treatment, my number was 74.0. I don’t know if this number is international scale or not.

That's pretty weird - to get an IS figure, you just need to apply the labs conversion factor. Simple arithmetic. Someone should be able to give you the labs conversion factor. 

However, if your conversion factor was x0.5 or lower that would retain your most recent result within MMR.

If you want to read more about conversion factors, it's on page 17 of our patient primer here: https://cmlsupport.org.uk/node/20097

David.

So it’s plausible that my doctor did not notice a number missing from my report and I’m worried for nothing? I really don’t want to switch from sprycel over a misunderstanding - the side effects of some of the other TKI seem pretty nasty and I tolerate this one well.

Anything is possible, but you really first need to get either your latest result on the IS, or the IS conversion factor. 

David.