Molecular Testing of CML Patients in 2021: Between Old and New Tools

Abstract

Introduction Chronic myeloid leukemia (CML) is a paradigm of precision medicine. The BCR-ABL1 fusion gene, resulting from the t(9;22) chromosomal translocation, encodes a deregulated tyrosine kinase responsible for leukemic transformation1 and represents both an ideal therapeutic target and a robust marker of minimal residual disease (MRD). Several tyrosine kinase inhibitors (TKIs) are now available for the treatment of CML patients.2 Their remarkable efficacy offers CML patients a near-normal life expectancy.3 Moreover, a proportion of patients may even discontinue the treatment, achieving the so-called 'treatment-free remission’ (TFR).4 A significant contribution to the optimization of CML treatment has been provided by the forward-looking implementation and standardization of molecular testing tools.