title: Real-Life Distribution of KRAS and NRAS Mutations in Metastatic Colorectal Carcinoma from French Routine Genotyping.
abstract: In metastatic colorectal cancer, KRAS and NRAS genotyping is mandatory before prescription of panitumumab or cetuximab. In order to perform such molecular tests, the French National Cancer Institute has set up a nationwide network of molecular centers. We report here the percentage of these mutations according to a prospective nonselected cohort of incident metastatic colorectal carcinoma patients. A total of 6,803 patients were tested between July 1, 2013, and December 31, 2013. Overall, 49.06% of patients harbored a mutation in either KRAS or NRAS. Mutations of NRAS exons 3 and 4 were very rare. No NRAS exon 3 at c.59 or exon 4 at c.117 mutations were retrieved, and only 1 NRAS exon 4 at c.146 mutation was detected. This present cohort is likely to represent most of the incident cases of metastatic colorectal adenocarcinomas arising in France over 6 months and is to our knowledge the largest population set genotyped for these genes in this condition. This is a unique opportunity to observe the frequency of RAS mutations regardless of most inclusion bias.
authors.affiliation: Rouen University Hospital, Rouen, France. nicolas.piton@chu-rouen.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Piton
authors.affiliation: Institut National du Cancer, Boulogne-Billancourt, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Lonchamp
authors.affiliation: Institut National du Cancer, Boulogne-Billancourt, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Nowak
authors.affiliation: Rouen University Hospital, Rouen, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Sabourin
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000556:secondary*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D005091:Exons / Q000235:genetics; D005602:France; D020558:GTP Phosphohydrolases / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D008565:Membrane Proteins; D020558:GTP Phosphohydrolases; C579846:NRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)