Table 1.

Methods of Detecting Disease Burden in Patients With Chronic Myeloid Leukemia

Method	Target	Sensitivity	Advantage	Disadvantage
Cytogenetics	Ph+ metaphases	1% to 5%	Widely available	Low sensitivity; bone marrow only
FISH	BCR–ABL fusion gene	0.1% to 5%	Rapid (1 to 2 days)	Does not detect other clonal events; has not been validated for monitoring response to TKI therapy
qRT–PCR	RNA sequence	0.001% to 0.01%	Highly sensitive	Suboptimal standardization; laboratory-intensive

BCR–ABL = breakpoint cluster region–Abelson; FISH = fluorescence in situ hybridization; Ph+ = Philadelphia chromosome–positive; qRT–PCR = quantitative reverse transcription polymerase chain reaction; TKI = tyrosine kinase inhibitor.

Data from Pelz AF, et al. Ann Hematol 2002;81(3):147–153;¹⁶ and Schoch C, et al. Leukemia 2002;16(1):53–59.¹⁷