title: Diffuse large B-cell lymphoma genotyping on the liquid biopsy.
abstract: Accessible and real-time genotyping for diagnostic, prognostic, or treatment purposes is increasingly impelling in diffuse large B-cell lymphoma (DLBCL). Cell-free DNA (cfDNA) is shed into the blood by tumor cells undergoing apoptosis and can be used as source of tumor DNA for the identification of DLBCL mutations, clonal evolution, and genetic mechanisms of resistance. In this study, we aimed at tracking the basal DLBCL genetic profile and its modification upon treatment using plasma cfDNA. Ultra-deep targeted next generation sequencing of pretreatment plasma cfDNA from DLBCL patients correctly discovered DLBCL-associated mutations that were represented in >20% of the alleles of the tumor biopsy with >90% sensitivity and ∼100% specificity. Plasma cfDNA genotyping also allowed for the recovery of mutations that were undetectable in the tissue biopsy, conceivably because, due to spatial tumor heterogeneity, they were restricted to clones that were anatomically distant from the biopsy site. Longitudinal analysis of plasma samples collected under rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP) chemotherapy showed a rapid clearance of DLBCL mutations from cfDNA among responding patients. Conversely, among patients who were resistant to R-CHOP, basal DLBCL mutations did not disappear from cfDNA. In addition, among treatment-resistant patients, new mutations were acquired in cfDNA that marked resistant clones selected during the clonal evolution. These results demonstrate that cfDNA genotyping of DLBCL is as accurate as genotyping of the diagnostic biopsy to detect clonally represented somatic tumor mutations and is a real-time and noninvasive approach to tracking clonal evolution and the emergence of treatment-resistant clones.
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.|Division of Hematology, Institute of Oncology Research, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Davide
authors.initials: D
authors.lastname: Rossi
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Fary
authors.initials: F
authors.lastname: Diop
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Spaccarotella
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Monti
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Zanni
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rasi
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Clara
authors.initials: C
authors.lastname: Deambrogi
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.|Division of Hematology, Institute of Oncology Research, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Valeria
authors.initials: V
authors.lastname: Spina
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.|Division of Hematology, Institute of Oncology Research, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Alessio
authors.initials: A
authors.lastname: Bruscaggin
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Favini
authors.affiliation: Laboratory of Informatics, University of Eastern Piedmont, Novara, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Serra
authors.affiliation: Division of Pathology, Department of Health Sciences, Maggiore della Carita' Hospital, University of Eastern Piedmont, Novara, Italy; and.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ramponi
authors.affiliation: Division of Pathology, Department of Health Sciences, Maggiore della Carita' Hospital, University of Eastern Piedmont, Novara, Italy; and.
authors.forename: Renzo
authors.initials: R
authors.lastname: Boldorini
authors.affiliation: Division of Hematology, Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy.
authors.forename: Robin
authors.initials: R
authors.lastname: Foà
authors.affiliation: Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gaidano
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D001706:Biopsy; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D060005:Genotyping Techniques; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000097:blood / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D008297:Male; D009154:Mutation; D011241:Prednisone / Q000008:administration & dosage; D011446:Prospective Studies; D000069283:Rituximab; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; C571759:R-CHOP protocol; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone