Acquiring additional deletions and changing percentages

[wwheather]

I am wondering about how CLL can change.  I know that over time you can acquire additional deletions to the one(s) your FISH test confirms but your Zap 70 status does not change.  Can you acquire these additional deletions even before treatment or is this more to do with the chemo?  Also, can the percentage of abnormal nuclei also change or do your percentages  remain constant?  

Thanks,

wwheather

[Cllcanada Top Poster CURE Hero]

Hi wwheather

The only thing that doesn't change is your IGHV mutation status, mutated or unmutated and the stereotypes VH genes that drive the CLL.

Certainly ZAP70 and CD38 percentages change, they are only indicators of the IGHV mutation status, and have an accuracy of about 70%. Further, unless ZAP70 was done in a CLL research facility, you need to discount it, because it is prone to handling errors... Even some major CLL centers no longer use the test...

Everything is changing all the time, but certainly treatment effects these changes greatly, often causing clonal evolution and rarely transformations, where by, the aggressive remaining CLL cells not killed by therapy, take over, filling the vacuum left by the departed B cells...

Addition deletions can be aquired at anytime, that is why FISH panels are being done prior to treatment more to assess 17p deletions and TP53 mutation status... not seen earlier on...

Change is constant...

~chris 

[wwheather in reply to Cllcanada]

Thanks Chris.   That was very helpful.  Clearly I have a lot to learn.

[Newdawn Administrator]

That is a helpful explanation Chris.

How the mutation status is established is the question I struggle with. I understand a specific test around this would be exceptionally difficult to obtain?

Rightly or wrongly, I'd assumed that ZAP70 and CD38 levels can be 'guestimated' at the flow cytometry stage though as stated, only with something like a 70% accuracy rate.

In the UK (and elsewhere), we often live in 'glorious' ignorance of our chromosomal profile and mutation status and FISH testing is only considered prior to treatment (whether that's right forms a completely different debate).

So the question I have is around the early diagnostic testing stage to establish CLL or other blood cancers. What level of information can we expect our haemotologists to draw from that which guides initial prognostic indicators at that stage? Or is it really down to the trend process in W&W to 'paint the progression landscape'.

I have asked my Consultant and I think he mumbled something in his characteristic 'I wish patients would be seen and not heard' style.

Newdawn 

[Cllcanada Top Poster CURE Hero in reply to Newdawn]

Oh dear Newdawn, your consultant sounds 'old school'... perhaps he needs an attitude adjustment... I'm certain you can do a bit of chiropractic work on that...😄

Flow cytometry surrogate markers for IGHV gene mutation are cheap, easy to do, and relatively accurate.. however you can get discourdant results, CD38- and ZAP70+...  Patients entering clinical trials usually get the Full Monty IGHV mutation test, but it is expensive, requires time and specialty  trained lab techs.

Clinically the surrogates are good enough... since they are only an indicator to time to first treatment, TTFT.

Yes, unmutated IGHV, has been shown to indicate a shorter overall survival in the days of chemotherapy, but today that may matter less, I suspect this to be the case...

Let's hope so...

~chris 

[Newdawn Administrator in reply to Cllcanada]

Thanks Chris, accords with what I understood.

I'm reluctant to say much on an 'open' post but believe me my Consultant doesn't get an easy ride with me and when I turned the computer screen he was intently staring at round to face me, I thought the poor old guy would swallow his teeth in shock.

If I can't change him, he'll be traded in I'm afraid

Hope you're doing well.

Newdawn