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Same PCR level from last 3 times

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Hi,
It's been more than 6 months since last August BCR-ABL reading is constant at 0.1432. Doc is suggesting to undergo a biopsy again to look for mutations and then change tki from Dastanib 100 mg to Bostunib or Nilotinib. Please advise!

If you are suggesting that the PCR level is measured exactly at 0.1432 every single time for the last three I would say that the lab is unreliable and I would switch labs.  The odds of the result coming out exactly the same to four decimal places is not possible.  They are either not running the PCR and just posting repeat results, or you need to play the lottery.  Sarcasm of course, but I would test at a different lab.  As far as a mutation goes that seems a bit early, especially being that the lab needs to be questioned about the results.  

If by some miracle it were 0.1432 three times in a row that would indicate a plateau at a safe level of CCyR and just above MMR.  IMHO no mutation should be suspected.  I hope others chime in but I think docs sometimes do more to scare patients than what the test results are indicating.

Thanks ColoradoGuy for your reply.
It's not exactly the same exact decimal value but similar to it all 3 times. The Doc wants it to reduce to 0.001 or to go down little but it's now happening and that's way she is concerned about the resistance to the medication.
It is a safe value but not MMR4. She wants to do another biopsy next month to find out what is happening. She may change or not change the current tki Dastanib according to the biopsy outcom.
I'm little worried why it's not going down further?

My doc seems to think that a plateau is safe and usually starts another slow decline or rise. I have had a few plateaus and a biopsy was never suggested. The only time there was a hint of concern and a switch of meds was when I had 0.32 jump to 1.2. Some people never reach MMR4 but there is no improved overall survival from CCyR. It would be nice to try treatment free which I doubt any doctor would do in CCyR but CCyR is safe. You responded to treatment which is great.

I still have not seen a second zero to the right of the decimal (getting closer though) and I am coming up on 5 years. Not everyone is the same and perhaps your doc has seen people race to MMR4 quickly. I would do nothing unless I saw a rise in two consecutive labs.

I get your point that it's a safe place to me with such low level. In the starting the response to Dastanib was very good and within a year the value was 0.14... but now there is a plateau and doctor wants to do something about it to know the reason. She will decide whether to change the tki or now by the results of the biopsy.
Let me know how many times did you get the plateau values?
How long it's OK to get a plateau and wait for it to go down ?

Something to keep in mind is that once you achieve complete cytogenetic remission (CCyR), progression free survival rates are no different statistically than with patients who achieve deeper molecular responses (i.e. PCR < 0.1%) including those who are "undetected".

Achieving a deeper molecular response is of course desirable and sets the stage for eventually testing going off drug, but in terms of living longer - no difference. It is in this light that one might consider other strategies to attack CML that augment current therapy.

In my case, high starting dose of dasatinib was less effective than a lower dose. Dasatinib is toxic (as are all TKI's). Trials have shown that lowering dasatinib dose increased response in some patients (up to a point).

It was only after my dose was reduced from 70 mg to 20 mg that my PCR levels plummeted. My doctor suspected this would happen because I was very sensitive (myelosuppression) to dasatinib (a good thing actually). You may be as well.

Consider adding nutrition support to your protocol. Selenium, Curcumin, vitamin D, zinc, vitamin C all have potent anti-cancer properties. Together with healthy diet, you may be able to break your plateau and decrease CML to very low levels. But keep in mind, once CCyR is achieved, the danger of CML is largely passed.

Myra, I know it's disappointing to hit a plateau but in terms of survival you are at a very safe spot. I love how doctors say what they want when, other than taking our meds as directed, we have no control over how we respond. You have responded very well. So well, that a test for mutations is pretty pointless. I would resist doing anything different at this moment. You are a partner in these decisions, don't let your doc make them all for you. After all, you're the one who has to put up with side effects, etc. It would be wonderful if everyone could see 0.0000 on PCR results, but it just doesn't work that way. Good luck!

I would say that I normally see a plateau for three test results before it goes down again.  My plateaus normally include at least one result that goes up from the previous results.  They do not always go down.  I don't know that there is a timeframe but just look for trends.  I don't think a long plateau would concern me.  A confirmed trend up would however.  

With your numbers I do not believe a mutation should be suspected.  That is not to say that your would not respond a little better on another TKI but not because there is a mutation present.  Keep us posted and I hope your numbers drop and give you more peace of mind very soon.