title: KRAS and BRAF mutations in Nigerian colorectal cancers.
abstract: OBJECTIVE
  Activation of the KRAS oncogene is implicated in colorectal carcinogenesis and mutations have been reported in 30-50% of cases. BRAF mutation, though less common, is also reported and importantly associated with shorter progression-free interval. This study aims to determine the KRAS and BRAF mutation statuses of Nigerian colorectal cancers (CRC).
  
  
  METHODS
  Mutation analysis was carried out on archival paraffin-embedded blocks of CRC tissues. KRAS codons 12, 13 and 61 and BRAF V600E were assessed by pyrosequencing after DNA extraction from 200 cases at the Leeds Institute of Molecular Medicine, St. James's University Hospital, UK. Mutation rates and the spectra were determined.
  
  
  RESULTS
  Pyrosequencing was successful in 112 of 200 cases. KRAS mutation in codons 12 and 13 was demonstrated in 23 of 112 cases (21%); none in codon 61. BRAF mutation in codon 600 was demonstrated in 4.5%.
  
  
  CONCLUSIONS
  This study shows that 21% of Nigerian CRC patients carry a KRAS mutation; half the rate in Caucasians; and that BRAF mutation also occurs in Nigerian CRC cancers.
authors: Department of Morbid Anatomy, College of Medicine University of Lagos.
authors: F B
authors: FB
authors: Abdulkareem
authors: L A
authors: LA
authors: Sanni
authors: S D
authors: SD
authors: Richman
authors: P
authors: P
authors: Chambers
authors: G
authors: G
authors: Hemmings
authors: H
authors: H
authors: Grabsch
authors: P
authors: P
authors: Quirke
authors: S O
authors: SO
authors: Elesha
authors: A F
authors: AF
authors: Banjo
authors: O A
authors: OA
authors: Atoyebi
authors: A A
authors: AA
authors: Adesanya
authors: C A
authors: CA
authors: Onyekwere
authors: J
authors: J
authors: Ojukwu
authors: E E
authors: EE
authors: Anomneze
authors: O
authors: O
authors: Rotimi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D044383:Black People / Q000235:genetics*; D003062:Codon; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009549:Nigeria; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D003062:Codon; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf