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PCR Ups and Downs

Hello All,

I thought i'd share my recent journey; certainly one i know other forum members have been on - PCR Ups and Downs. My treatment with Tasigna has been pretty good although when moving from the US to the UK i found the differences in lab testing showed only 0.6% BCR-ABL after 16 months on Tasigna - the US tests told me I was PCRU. Since then it was a downward trend, reaching 0.06% in Nov 2012.

My March 2013 results saw a rise up to 0.227% - not cool! I was disheartened as i had been experiencing a nice downward trend over the previous 12 months. However, the rational side of me, who reads about CML quite a lot, had to remember that people do have spikes on their PCR tests. The irrational side of me couldn't help think about the 'what ifs?'

The good news today is that i'm back down to 0.047% - a great result and back on the march to MR4.

So the bit i want to share is some of us do have spikes and they often seem to go down. So if you have an uptick in your numbers do not panic. Think positive and abate the 'what ifs?' with this story (which is certainly not unique to me). And if it does end up being the start of a trend remember there are several TKIs available now.

As an aside - I do wonder if we have more of thee spikes than we realise. Typically we only get tested from a snapshot every 3 months. I could be having lots of spikes and them not be noticed if i don't have a PCR test that week, but then my numbers head back down and i'm all good again when it comes to PCR Test day. Just a thought.

Best wishes to all

Chris

Hi Chris,

I think that's a good point... how do you know if something is a blip, and how do you know you haven't had blips that just weren't tested?

As another example, 3 weeks ago I had a FBC done which showed 1000 neutrophils, which was a drop of around 400 on my previous result. So, they asked me to come back in again the next week to keep an eye on it and they were back up to 1300. Had we not tested in that middle week, we'd never have known and I'd never have stressed about it!

David.

Hi Chris,

First let me say that it was with relief that I read your latest PCR result was down again and lower than the previous low- obviously the higher one was a 'blip' as they say, but nevertheless I can relate to your 'disappointment' in the March result!

Back in the 'old' days prior to 2G TKIs, I experienced several highs and lows from my lowest ever baseline at 0.57%.
Over a period of several months the graph of my results looked like a small mountain range- not too high (never lost CCyR) but never achieving the previous low either.

The story was of course that I had 'developed' an IM mutation and the the rest of my case is history, but my point for raising the 'what if' the intermittent testing (3 monthly PCRs) is not catching other possible 'highs'.. like if the tested every 2 weeks for instance... is this:

I am sure you are right and more frequent results would show ups as well as downs. However, given that RT Q-PCR (as we should now call it) only really works on the molecular level- unlike the more 'crude' blood tests (and to answer David's point) that quantify the blood cells in the peripheral blood - which is certainly a snapshot and as the numbers are usually counted by a machine that identifies the cells by size, you can understand how those tests are entirely different to a very sophisticated test like PCR.

I think the PCR methodology is far more profound than we might realise. After all it is highly unstable except at the lower levels of disease, which is why labs use normal cytogenetics/FISH to test PH+ cells at higher levels after diagnosis- and anything above 10% or lower BCR-ABL.

I think the anomalies in individual PCR results are just that- for all sorts of reasons to do with samples- how they were taken and stored/how they traveled to the destination lab/how quickly they were then tested/the temperature of the lab on any given day... etc. etc.

Blips (highs) are generally blips, and the thing to concentrate on is the 'trend'- usually of 3 results showing a trend (up or down). My trend was up and down but the downs were always higher than the last down.. so that was my trend.

If we view it as a mountain range- then are there hills and plateaus in front, and do they eventually lead to level lowland?

I am sure you will keep on going towards the lowlands of MR4 and maybe over time, even lower ;o)

Best... Sandy

Hi Sandy,
what did you mean by developed IM mutation?please,could you explain it to me?
i was diagnosed with CML last year February'12.i ve been first half year on imatinib,than nilotinib,and now for 4 months on dasatinib.i had brc-abl 0.78 in March.i was waiting for results,but when i saw a doctor,he did not say much just 0.78.

Hi Hannah,

I developed an imatinib resistant mutation- there are several- probably because I was diagnosed in late chronic phase so my disease what cranking up. Although I responded well to imatinib I eventually lost that response because of the mutation. It is not known whether imatinib allows mutations to develop in some people- certainly not the majority- or whether the mutations were there in the first place- just not visible.

You look to be doing very well- at 0.78%. Hopefully dasatinib (which by the way - if it had been available at the time, would have dealt very well with the mutation I had) will continue to put you into deep remission.

Best... Sandy

thank you,Sandy.
so,what kind of treatment are you on?did you have Bone marrow transpl.?How many yeras ago?please,can you write your story,if you can.many thx,Hannah

Hannah.... you can read my story on the blog page here http://classic.caringbridge.org/europe/sandycraine/

I no longer update but I have had negative pct's since early 2006....and I do not need to take any specific therapy for CML. I am still closely monitored every 4 months.

Best wishes,
Sandy