My lab results at diagnosis were as follows:
"Quantitative PCR: bcr-abl1/abl1 (IS) = 40,98% with expression of control gene abl1 = 1 308 000"
FISH test showed translocation t(9;22) in 95% of cells. Started therapy with Imatinib.
Three months later:
qPCR = 24,17% with expression of control gene abl1 = 629 000
FISH showed a complex translocation t(7;9;22) present in 75% of cells.
Imatinib was declared as failure, started on Tasigna instead.
Four months later (now):
qPCR = 4,44% with abl1 = 624 000
FISH showed t(7;9;22) presence of 30% as well as trisomy 8 in 6% of cells.
Doctor (hematologist) pointed at expression of abl1 gene as being too high (624k), and that together with trisomy 8 it shows that Tasigna (and any other TKI) are ineffective, with bone marrow transplant being the only remaining option.
Whenever someone quotes qPCR tests they only mention the percentage. So I'm wondering what is the significance of control gene expression? What are high or low values for this number?