1 From The University of Texas MD Anderson Cancer Center; Fred Hutchinson Cancer Research Center/Seattle Cancer Care Alliance; Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine; Fred & Pamela Buffett Cancer Center at The Nebraska Medical Center; Robert H. Lurie Comprehensive Cancer Center of Northwestern University; Memorial Sloan-Kettering Cancer Center; Dana-Farber/Brigham & Women’s Cancer Center; Huntsman Cancer Institute at the University of Utah; The Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute; Massachusetts General Hospital Cancer Center; Stanford Cancer Institute; Vanderbilt-Ingram Cancer Center; Fox Chase Cancer Center; Duke Cancer Institute; St. Jude Children’s Research Hospital/The University of Tennessee Health Science Center; Moffitt Cancer Center; University of Alabama at Birmingham Comprehensive Cancer Center; UCSF Helen Diller Family Comprehensive Cancer Center; The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins; City of Hope Comprehensive Cancer Center; Roswell Park Cancer Institute; and National Comprehensive Cancer Network.
The 2014 NCCN Clinical Practice Guidelines in Oncology for Chronic Myelogenous Leukemia recommend quantitative reverse-transcription polymerase chain reaction (QPCR) standardized to International Scale (IS) as the preferred method for monitoring molecular response to tyrosine kinase inhibitor (TKI) therapy. A BCR-ABL1 transcript level of 10% or less (IS) is now included as the response milestone at 3 and 6 months. Change of therapy to an alternate TKI is recommended for patients with BCR-ABL1 transcript levels greater than 10% (IS) at 3 months after primary treatment with imatinib. Continuing the same dose of TKI or switching to an alternate TKI are options for patients with BCR-ABL1 transcript levels greater than 10% (IS) at 3 months after primary treatment with dasatinib or nilotinib. The guidelines recommend 6-month evaluation with QPCR (IS) for patients with BCR-ABL1 transcript levels greater than 10% at 3 months. Monitoring with QPCR (IS) every 3 months is recommended for all patients, including those who meet response milestones at 3, 6, 12, and 18 months (BCR-ABL1 transcript level ≤10% [IS] at 3 and 6 months, complete cytogenetic response at 12 and 18 months).