6 replies to this topic

[shaynalee]

My husband just got his first pcr result since his dx in March. I notice that a lot of people reference the IS scale, but his doctor doesn't have his numbers on that. He considered his first bmb results his "100%". Anyone else doc do that? He came in at 26% at 3 months of being on sprycel. Is that a good result or is it slow? Any info or personal experience would be great!

[Trey]

Without reference points (either IS scale or PCR at diagnosis) there is no real way to measure progress from his PCR.  The BMB 100% is not equivalent for reference point purposes.  But in very general terms that PCR result is good for 3 months. 

[scuba]

My husband just got his first pcr result since his dx in March. I notice that a lot of people reference the IS scale, but his doctor doesn't have his numbers on that. He considered his first bmb results his "100%". Anyone else doc do that? He came in at 26% at 3 months of being on sprycel. Is that a good result or is it slow? Any info or personal experience would be great!

 

Is it PCR or FISH that is being reported at 3 months post diagnosis - or both? Usually after diagnosis they conduct FISH tests to verify that the percentage of CML cells they can see under the microscope is dropping. PCR doesn't mean much until FISH is at or close to zero. What was the BMB test revealing? (cytogenetics, PCR,)

[shaynalee]

Maybe it was the fish then? Our doctor explains nothing, so we are trying to figure it out in our own. All I understand is that at dx it was 100% and now it's 26%

[shaynalee]

Also scuba, I had posted his bmb results a while back in March when we first got them. Not sure if you would be able to find them, but they are in the forum somewhere!

[scuba]

Maybe it was the fish then? Our doctor explains nothing, so we are trying to figure it out in our own. All I understand is that at dx it was 100% and now it's 26%

 

Makes sense it would be FISH, but better to confirm.

 

Assuming it is FISH - you went from 100% to 26% in three months. That's a good result. Three months from now you should be a lot lower. Goal is to get to FISH = zero in 18 months. Many can achieve that result very quickly. I achieved FISH = zero in 7 months once I was able to stay on Sprycel and starting out at FISH = 100%. 

 

FISH = zero means that under the microscope they do not see any CML cells (dyed to reveal the abnormal chromosome using fluorescence). Cytogenetic response is the best predictor of long term progression free survival. Doctors want to see this number come down as quickly as possible and become zero.

 

Once FISH = zero - then the only way to determine your level of disease is with the PCR test. This test measures protein products produced uniquely by the CML cells. You can't see the cells (too few of them), but they are there producing protein products that the PCR test can 'detect' - up to a point. Detection limits are usually described in the literature as many as one million CML cells are remaining below which the PCR measuring system can not detect. To put in perspective - you generate two million red blood cells each second. You have trillions of blood cells. One million CML cells dispersed in your blood volume is a small number.

 

PCR testing becomes relevant once FISH gets below 1%. There is a rough correlation that 1% FISH is approximately 1% PCR.

After FISH falls to zero, PCR will continue to drop as therapy continues to have effect. A PCR of 0.1% (using the International Scale) is another milestone and is termed Major Molecular Remission. A PCR of 0.01% is considered by many labs to be the limit of detection. Below 0.01% some labs report nothing detected, some labs will print out third or fourth decimal place numbers. Any number posted past the second decimal place is pretty much meaningless - but we CML'ers tend to hang on every number comparing whether it went up or down. Because it's printed on the report - we pay attention to it. When you consider that the error range in the test is a factor of 10 (one log) - it's pretty clear that fluctuations within one log don't mean very much. Trends of one log or more are what we look for.

 

Your focus right now is seeing your FISH drop to zero. You're in a great place when that happens. 

 

A good resource on CML testing and procedures is here:

 

http://www.nccn.org/...guidelines/cml/

 

Trey has a good summary as well and he can post the link.

[shaynalee]

Very helpful scuba, thank you! That all makes much more sense now 😄