6 replies to this topic

[TeddyB]

What is the exact (if any) definition of remission in regards to CML?

CHR, CCYR, MMR, PCRU, or just a constant downward trend in PCR?

Teddy

[scuba]

The "remission" that matters is the one that leads to progression free survival.

That "remission" is CCYR = Complete Cytogenetic Response. CCyR is determined by FISH (peripheral or bone marrow). FISH = zero = CCyR. Those who achieve CCyR within 18 months have as good a survival chance as those who achieve MMR or PCRU.

The deeper the response and the more quickly the response occurs leading to PCRU is an indication of potential disease eradication. Those who achieve PCRU and hold it for two years have a 40% chance of not having the disease show up again (IRIS study). Most choose to stay on the drugs preferring not to take a chance at recurrence.

But in terms of functional "remission", it is the CCyR that matters most.

[PhilB]

'Remission' means you had cancer, we treated it, it went away and we don't have to treat you any more.  It isn't really a term that applies in CML - unless perhaps you are one of those people who have discontinued TKIs following prolonged PCRu (and the jury is still out on whether that is really 'remission' or just a very slow return to detectable levels), or if you have had a stem cell transplant - but even then in most cases you'd still be takling a TKI just in case.

The 'R' word for CML is response and a good one means you keep taking the drug and the disease stays at levels too low to harm you.  Basically all you are really looking for is to stop the CML from ever getting to a dangerous level and so all you really need is stability.

The two big numbers they use in statistical analysis of progression rates are CCyR and MMR.  MMR mean the odds of progression are very small indeed.  CCyR maintained for a couple of years is as good as MMR.  Importantly though, they are both just random points that happen to have been picked to divide populations in measuring respone.  There is nothing magic about having a 3 log reduction vs a 2.9 or a 3.1, and nothing in particular about a <1 in 20 cytology vs a <1 in 19 or a <1 in 21.

Practically though your choice is going to be: 1) to ignore this and say 'I'm in remission', or 2) to spend the next 30 years explaining the difference between response and remission to people.  The good news is that, unless you die of something else first, you are likely to have the next 30 years to do that explaining in.  On the other hand, I'm sure you can think of better things to do with the next 30 years (or the next 13 hours if the Mayan's had it right)

[TeddyB]

Thanks for replying guys.

I just read a lot of people saying their doctor told them they were in remission, and that is not from discontinuation.

I thought, wow, this must be a broad definition, as i didnt think there was 1 exact definition for remission in this CML of ours.

As you point out phil, it might be easier just to say your in remission, than to say that you have good response.

Oh yeah, the end of the world i forgot that, better prepare then

I will be preparing by watching this: http://www.youtube.c...h?v=sOzFDuNgWuM

[Trey]

The term used by the leading CML specialists is "response", not "remission", since remission implies a cure or progress toward a cure.  Note that the "R" in CHR, CCR, MMR, and CMR is "response", not remission.  This is more than just a technical difference, since other types of curable cancer have remission, but we have response to drug therapy.  The exception is a bone marrow transplant where remission (cure) is the goal.  The goal of our drug therapy is to gain maximum response to the drug therapy which 1) halts disease progression, and 2) puts the disease into a continuous state of very low level chronic stage CML.  So the answer to your question is that we have various levels of response to treatment, not a true remission in the technical sense.  Trying to assign a point where "remission" occurs in CML treatment would be hard to categorize, since one would need to assign an arbitrary point where "remission" occurs, and that is problematic since patients in true remission no longer need treatment.  They are only treated again if they relapse. 

But if family and friends don't understand that, then using the term "remission" with them is certainly understandable.  But you asked for a technical answer, so there it is.

You can read more here:
http://community.lls.org/message/34624

[CallMeLucky]

I've used the term "drug induced remission".  It's not technically correct but it helps people to understand where I am at in one phrase.

[TeddyB]

Thank you all for replying.

The world didnt end, wow.