New Tool for Monitoring Molecular Response in Patients with Chronic Myeloid Leukemia

Objective: Chronic myeloid leukemia treatment monitoring using polymerase chain reaction-based peripheral blood testing of t 9;22 BCR-ABL1 provides improved test sensitivity over cytology but suffers from inadequate standardization in most laboratories due to variations inherent in the existing polymerase chain reaction methodologies. We performed the initial analytic performance evaluation of a novel competitive template-based peripheral blood b2a2/b3a2 transcript abundance method, called standardized nucleic acid quantification (SNAQ) test, with hypothesis that this will produced more consistent results with less frequent interlaboratory variations. Materials and Methods: Thirty-six chronic myeloid leukemia patients treated at our institution were enrolled. We compared SNAQ test with 2 laboratory developed test at the MD Anderson molecular diagnostic laboratory and Cancer Genetics Institute for analyzing BCR-ABL1 from peripheral blood samples. Each test result (n=36) was ranked against all the other samples tested by the same method. Results: The Pearson correlation between SNAQ and laboratory developed test done at 2 labs was met by correlations of 0.97, 0.96, 0.96, and 0.94. Analysis of variance of log %BCR-ABL1 interlaboratory results indicated no significant difference (P=0.98). Post hoc analysis of method agreement showed the SNAQ method had a 95% limit of agreement of ±3-fold between laboratories. Conclusions: In this pilot study, SNAQ methodology performed consistent with half-log accuracy. Additional studies from a larger sample size and correlation with clinical outcomes are required to confirm this observation.