title: Clinical validation of the detection of KRAS and BRAF mutations from circulating tumor DNA.
abstract: Assessment of KRAS status is mandatory in patients with metastatic colorectal cancer (mCRC) before applying targeted therapy. We describe here a blinded prospective study to compare KRAS and BRAF mutation status data obtained from the analysis of tumor tissue by routine gold-standard methods and of plasma DNA using a quantitative PCR-based method specifically designed to analyze circulating cell-free DNA (cfDNA). The mutation status was determined by both methods from 106 patient samples. cfDNA analysis showed 100% specificity and sensitivity for the BRAF V600E mutation. For the seven tested KRAS point mutations, the method exhibited 98% specificity and 92% sensitivity with a concordance value of 96%. Mutation load, expressed as the proportion of mutant alleles in cfDNA, was highly variable (0.5-64.1%, median 10.5%) among mutated samples. CfDNA was detected in 100% of patients with mCRC. This study shows that liquid biopsy through cfDNA analysis could advantageously replace tumor-section analysis and expand the scope of personalized medicine for patients with cancer.
authors.affiliation: 1] U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France. [2] Sysdiag UMR3145 CNRS, CAP DELTA, Montpellier, France.
authors.forename: Alain R
authors.initials: AR
authors.lastname: Thierry
authors.affiliation: 1] U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France. [2] Sysdiag UMR3145 CNRS, CAP DELTA, Montpellier, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Mouliere
authors.affiliation: 1] U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France. [2] Sysdiag UMR3145 CNRS, CAP DELTA, Montpellier, France.
authors.forename: Safia
authors.initials: S
authors.lastname: El Messaoudi
authors.affiliation: Unité de Biostatistique, Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Mollevi
authors.affiliation: Laboratoire de Biologie Spécialisée, Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Lopez-Crapez
authors.affiliation: Sysdiag UMR3145 CNRS, CAP DELTA, Montpellier, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Rolet
authors.affiliation: Centre Hospitalier Universitaire de Clermont-Ferrand, Service de Chirurgie Digestive Unité d'Oncologie Digestive, UMR Unité Inserm/Université d'Auvergne U1071, Clermont-Ferrand, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Gillet
authors.affiliation: U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France.
authors.forename: Celine
authors.initials: C
authors.lastname: Gongora
authors.affiliation: Centre Hospitalier Universitaire de Clermont-Ferrand, Anatomie Pathologique, Unité d'Oncologie moléculaire, Clermont-Ferrand, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Dechelotte
authors.affiliation: U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
authors.affiliation: U896 INSERM, Institut Recherche en Cancérologie de Montpellier, Montpellier, France.
authors.forename: Maguy
authors.initials: M
authors.lastname: Del Rio
authors.affiliation: Laboratoire de Biologie Spécialisée, Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Pierre-Jean
authors.initials: PJ
authors.lastname: Lamy
authors.affiliation: Service de Pathologie, Unité de Biopathologie Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Bibeau
authors.affiliation: Centre Hospitalier Universitaire de Limoges, Service de Chirurgie Digestive, Centre d'Investigation Clinique, INSERM 0801, Limoges, France.
authors.forename: Michelle
authors.initials: M
authors.lastname: Nouaille
authors.affiliation: Service de Chirurgie Digestive, Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Loriot
authors.affiliation: Centre Hospitalier Universitaire de Clermont-Ferrand, Anatomie Pathologique, Unité d'Oncologie moléculaire, Clermont-Ferrand, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Jarrousse
authors.affiliation: Sysdiag UMR3145 CNRS, CAP DELTA, Montpellier, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Molina
authors.affiliation: Centre Hospitalier Universitaire de Limoges, Service de Chirurgie Digestive, Centre d'Investigation Clinique, INSERM 0801, Limoges, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Mathonnet
authors.affiliation: Centre Hospitalier Universitaire de Clermont-Ferrand, Service de Chirurgie Digestive Unité d'Oncologie Digestive, UMR Unité Inserm/Université d'Auvergne U1071, Clermont-Ferrand, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Pezet
authors.affiliation: Service de Chirurgie Digestive, Institut du Cancer de Montpellier, Montpellier, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Ychou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017354:Point Mutation; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D018631:ras Proteins / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins