title: High concordance of KRAS status between primary colorectal tumors and related metastatic sites: implications for clinical practice.
abstract: OBJECTIVE
  Several studies have suggested that KRAS somatic mutations may predict resistance to cetuximab- and panitumumab-based treatments in metastatic colorectal cancer (CRC) patients. Nevertheless, most experiences were conducted on samples from primaries. The aim of this study was to evaluate the grade of concordance in terms of KRAS status between primaries and related metastases.
  
  
  METHODS
  We analyzed KRAS codon 12 and 13 mutations from formalin-fixed sections of 107 CRC primaries and related metastases. Eight pairs were excluded from the analysis because of the low amount of tumor tissue in the available samples. The main characteristics were: 50 men, 49 women; median age at diagnosis, 71 years (range, 41-84). The metastatic sites analyzed were the liver in 80 patients (80.8%), lung in seven patients (7.1%), and other sites in 12 patients (12.1%).
  
  
  RESULTS
  A KRAS mutation was found in 38 (38.4%) primary tumors and in 36 (36.4%) related metastases. The rate of concordance was 96.0% (95% confidence interval, 90.0%-98.9%). Discordance was observed in only four (4%) patients.
  
  
  CONCLUSIONS
  Our results indicate that the detection of KRAS mutations in either primary or metastatic tumors from patients with CRC is concordant and this assessment could be used to predict response to targeted therapies such as cetuximab and panitumumab.
authors.affiliation: Department of Oncology, University Campus Bio-Medico, Rome, Italy. d.santini@unicampus.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Santini
authors.forename: Fotios
authors.initials: F
authors.lastname: Loupakis
authors.forename: Bruno
authors.initials: B
authors.lastname: Vincenzi
authors.forename: Irene
authors.initials: I
authors.lastname: Floriani
authors.forename: Irene
authors.initials: I
authors.lastname: Stasi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Canestrari
authors.forename: Eliana
authors.initials: E
authors.lastname: Rulli
authors.forename: Paolo Enrico
authors.initials: PE
authors.lastname: Maltese
authors.forename: Francesca
authors.initials: F
authors.lastname: Andreoni
authors.forename: Gianluca
authors.initials: G
authors.lastname: Masi
authors.forename: Francesco
authors.initials: F
authors.lastname: Graziano
authors.forename: Giacomo Giulio
authors.initials: GG
authors.lastname: Baldi
authors.forename: Lisa
authors.initials: L
authors.lastname: Salvatore
authors.forename: Antonio
authors.initials: A
authors.lastname: Russo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perrone
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Tommasino
authors.forename: Mauro
authors.initials: M
authors.lastname: Magnani
authors.forename: Alfredo
authors.initials: A
authors.lastname: Falcone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tonini
authors.forename: Annamaria
authors.initials: A
authors.lastname: Ruzzo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005260:Female; D011905:Genes, ras; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009362:Neoplasm Metastasis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D012189:Retrospective Studies; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins