Re: BCR-ABL numbers...how high have you ever gone?

[Guest guest]

I was at ninety something % when I was dx. I'm curious about how high you

can go too. I don't think it is possible to get to 100% and still be alive,

but that's just a guess. I can't remember if the percentage is of white

blood cells or all blood cells.

[ ] BCR-ABL numbers...how high have you ever gone?

Could I please have some input on my question of numbers for the BCL ABL

test. What is high and what is low? I am told that anything over zero is

too high.but could someone please advise more. Since I have been looking at

the posts, I have seen one that was 5.9% or so and that is all and he went

to zero. Can someone please share. Does it go to 100%....Annette

Livingston MF and CML

[Guest guest]

Hi Annette,

There are several different tests that measure the BCR-ABL in your CML. The

simplest test is the BMB. It looks at 20 cells. At diagnosis most people

will have 20/20 cells with the CML. This would mean 100 %.

The next one is the FISH test. It looks at 200 cells. Again, at diagnosis

most people are at 100% .

Then there is the PCR test. This one looks at 100,000 cells and reports

several different ways. At diagnosis time the result it gives varies with

the different labs. It could be a number anywhere between 10 and 50. This

would correspond to 100%.

The PCR test measures the % in a different way.

I hope I haven't muddied it up too much.

Zavie

From: [mailto: ] On Behalf Of

Annette Livingston

Sent: November-15-10 4:26 PM

Subject: [ ] BCR-ABL numbers...how high have you ever gone?

Could I please have some input on my question of numbers for the BCL ABL

test. What is high and what is low? I am told that anything over zero is

too high.but could someone please advise more. Since I have been looking at

the posts, I have seen one that was 5.9% or so and that is all and he went

to zero. Can someone please share. Does it go to 100%....Annette

Livingston MF and CML

[Guest guest]

On PCR, it also depends on which scale is being used - i have seen some results

reported above 100% on the international scale at diagnosis though never fully

understand why (I think it must be to do with the control sample size). In any

case, most people are 70% to 100% at DX by PCR (my own hospital assumes 70% as

baseline but others work on 100% - perfectly possible to be that at DX, and I

don't think it makes all that much difference where you are).

that having been said, the PCR results only really come into their own once the

numbers by standard cytogenics (the 20/20 test) or Fish (typically measuring 500

cells) are very low. And then, a stable number below 1% and better below 0.1 and

even better below 0.01 and ideally zero by PCR, is what they are looking for.

As well as a trend - a faster drop is thought to be better but not essential.

>

> I was at ninety something % when I was dx. I'm curious about how high you

> can go too. I don't think it is possible to get to 100% and still be alive,

> but that's just a guess. I can't remember if the percentage is of white

> blood cells or all blood cells.

>

>

>

> [ ] BCR-ABL numbers...how high have you ever gone?

>

>

>

>

>

> Could I please have some input on my question of numbers for the BCL ABL

> test. What is high and what is low? I am told that anything over zero is

> too high.but could someone please advise more. Since I have been looking at

> the posts, I have seen one that was 5.9% or so and that is all and he went

> to zero. Can someone please share. Does it go to 100%....Annette

> Livingston MF and CML

>

>

[Guest guest]

PCR results are a ratio of the bcr/abl to the control gene typically

expressed as a percent. That is why they can over over 100. If there

is more bcr/abl than control gene then the result would be greater

than 100%.

As for the question on how low you want to go--it depends on the

sensitivity of the test. The PCR test is not standardized (and does

not always use the same control gene) so the answer is lab dependent.

Most labs will tell you what value is equivalent to MMR. There is a

pretty wide difference in quality of PCR tests--it really does depend

on who is running the test. The lower the number the safer you are--

but you can reach zero at one lab and not be negative at another with

a more sensitive test.

Dorothy

On Nov 16, 2010, at 2:15 AM, willoughbyr@... wrote:

> On PCR, it also depends on which scale is being used - i have seen

> some results reported above 100% on the international scale at

> diagnosis though never fully understand why (I think it must be to

> do with the control sample size). In any case, most people are 70%

> to 100% at DX by PCR (my own hospital assumes 70% as baseline but

> others work on 100% - perfectly possible to be that at DX, and I

> don't think it makes all that much difference where you are).

>

> that having been said, the PCR results only really come into their

> own once the numbers by standard cytogenics (the 20/20 test) or Fish

> (typically measuring 500 cells) are very low. And then, a stable

> number below 1% and better below 0.1 and even better below 0.01 and

> ideally zero by PCR, is what they are looking for. As well as a

> trend - a faster drop is thought to be better but not essential.

>

>