Next-generation sequencing of FLT3 internal tandem duplications for minimal residual disease monitoring in acute myeloid leukemia

// Jean-Emmanuel Bibault 1,3,* , Martin Figeac 2,3,* , Nathalie Helevaut 1 , Celine Rodriguez 1 , Sabine Quief 2,4 , Sheherazade Sebda 2,4 , Aline Renneville 1,3,5 , Olivier Nibourel 1,3,5 , Philippe Rousselot 6 , Berengere Gruson 7 , Herve Dombret 8 , Sylvie Castaigne 6 and Claude Preudhomme 1,3 1 Laboratory of Hematology, CHRU de Lille, France 2 Functional and Structural Genomic Platform, Lille, France 3 University of Lille Nord de France, Lille, France 4 Institut Pour la Recherche sur le Cancer de Lille, Lille, France 5 Inserm, UMR-S1172, Lille, France 6 Department of Hematology, Hopital de Versailles, Le Chesnay, Universite de Versailles-Saint Quentin, Versailles, France 7 Department of Hematology, CHU d’Amiens, Amiens, France 8 Department of Hematology, Hopital Saint Louis, AP-HP, Paris, France * These authors have contributed equally to this work Correspondence to: Claude Preudhomme, email: // Keywords : acute myeloid leukemia, FLT3 internal tandem duplication, minimal residual disease, next-generation sequencing Received : November 08, 2014 Accepted : May 25, 2015 Published : June 02, 2015 Abstract Minimal Residual Disease (MRD) detection can be used for early intervention in relapse, risk stratification, and treatment guidance. FLT3 ITD is the most common mutation found in AML patients with normal karyotype. We evaluated the feasibility of NGS with high coverage (up to 2.4.10 6 PE fragments) for MRD monitoring on FLT3 ITD. We sequenced 37 adult patients at diagnosis and various times of their disease (64 samples) and compared the results with FLT3 ITD ratios measured by fragment analysis. We found that NGS could detect variable insertion sites and lengths in a single test for several patients. We also showed mutational shifts between diagnosis and relapse, with the outgrowth of a clone at relapse different from that dominant at diagnosis. Since NGS is scalable, we were able to adapt sensitivity by increasing the number of reads obtained for follow-up samples, compared to diagnosis samples. This technique could be applied to detect biological relapse before its clinical consequences and to better tailor treatments through the use of FLT3 inhibitors. Larger cohorts should be assessed in order to validate this approach.