You are here

Very different numbers for BCR-ABL1/ABL1 from different labs

Categories:

Hello all,
I was diagnosed with CML in November 2024, and am now three months into my treatment. As I'm not on insurance, I was able to get tested across three different labs on my own dime for the first quantitative test after 3 months.. The three came back with wildly different results (14.48% vs. 8.51% vs. 4.83%) for the IS-normalized BCR-ABL1/ABL1 ratio.

Is this to be expected? Should I bring this up with my doctor? My oncologist asked me to get myself tested in the hospital (which outsources the results to a 3rd party lab called Core) and is between 1.5 to 3 times more expensive than all the other labs. Even testing it directly with Core is around 1/3 cheaper than testing via the hospital. The reason I did 2 tests (and then 3) was to check if the tests were comparable and if so, to check with the oncologist if I could shift to a cheaper testing lab. But that none of the three agree with each other has come as a suprise.

Should I bring this up with my oncologist, or just ignore the other results?

Thanks! (See below for the full results)

I've given the data from each of the lab in this format:
Date (Lab)
Method
BCR-ABL1 count
ABL1 count
BCR-ABL1/ABL1 ratio
BCR-ABL1/ABL1 ratio (IS normalized)

2025-02-20 (Core)
quantitative Real-Time PCR
31,344.605
138,534.6
22.63%
14.48%

2025-02-22 (Medplus)
quantitative Reverse-Transcription PCR
12,215
158,418
7.71%
4.83%

2025-02-28 (Medall)
quantitative Reverse-Transcription PCR
18,831
162,071
11.61%
8.51%

I believe that the PCR test is less accurate during early treatment until you achieve a complete cytogenetic response. You could get a karyotype and/or FISH test to corroborate the PCR results, but it looks like you're getting a good response to treatment.

"BCR and ABL1 t(9;22) by FISH

Test Name Alias: BCR and ABL1 t(9;22) by FISH | BCR and ABL1 Dual Fusion | 946"

Here are my numbers at three months of treatment: 003.590% IS (1.438%), bone marrow biopsy - no residual myeloproliferative features but detected 1/20 metaphases containing the Philadelphia chromosome, FISH - 5.5%

I agree with RC, a FISH is typically used to see if you achieve a cytogenic response. Although much more invasive, it is probably better at handling the larger number of copies. But also like RC states, you are on a good trajectory and that’s what’s important. Tests from competing labs can fluctuate but in general they all tell the same story.