title: KRAS mutations in primary tumours and post-FOLFOX metastatic lesions in cases of colorectal cancer.
abstract: BACKGROUND
  KRAS mutations are predictive markers for the efficacy of anti-EGFR antibody therapies in patients with metastatic colorectal cancer. Although the mutational status of KRAS is reportedly highly concordant between primary and metastatic lesions, it is not yet clear whether genotoxic chemotherapies might induce additional mutations.
  
  
  METHODS
  A total of 63 lesions (23 baseline primary, 18 metastatic and 24 post-treatment metastatic) from 21 patients who were treated with FOLFOX as adjuvant therapy for stage III/IV colorectal cancer following curative resection were examined. The DNA samples were obtained from formalin-fixed paraffin-embedded specimens, and KRAS, NRAS, BRAF and PIK3CA mutations were evaluated.
  
  
  RESULTS
  The numbers of primary lesions with wild-type and mutant KRAS codons 12 and 13 were 8 and 13, respectively. The mutational status of KRAS remained concordant between the primary tumours and the post-FOLFOX metastatic lesions, irrespective of patient background, treatment duration and disease-free survival. Furthermore, the mutational statuses of the other genes evaluated were also concordant between the primary and metastatic lesions.
  
  
  CONCLUSIONS
  Because the mutational statuses of predictive biomarker genes were not altered by FOLFOX therapy, specimens from both primary tumours and post-FOLFOX tumour metastases might serve as valid sources of DNA for known genomic biomarker testing.
authors.affiliation: Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawamoto
authors.forename: K
authors.initials: K
authors.lastname: Tsuchihara
authors.forename: T
authors.initials: T
authors.lastname: Yoshino
authors.forename: N
authors.initials: N
authors.lastname: Ogasawara
authors.forename: M
authors.initials: M
authors.lastname: Kojima
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: A
authors.initials: A
authors.lastname: Ochiai
authors.forename: H
authors.initials: H
authors.lastname: Bando
authors.forename: N
authors.initials: N
authors.lastname: Fuse
authors.forename: M
authors.initials: M
authors.lastname: Tahara
authors.forename: T
authors.initials: T
authors.lastname: Doi
authors.forename: H
authors.initials: H
authors.lastname: Esumi
authors.forename: Y
authors.initials: Y
authors.lastname: Komatsu
authors.forename: A
authors.initials: A
authors.lastname: Ohtsu
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000235:genetics; D058534:Class I Phosphatidylinositol 3-Kinases; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D011905:Genes, ras; D006801:Humans; D002955:Leucovorin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D009944:Organoplatinum Compounds; D011518:Proto-Oncogene Proteins; D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D066246:ErbB Receptors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D002955:Leucovorin; D005472:Fluorouracil