title: RAS, BRAF, and TP53 gene mutations in Taiwanese colorectal cancer patients.
abstract: BACKGROUND
  Colorectal cancer (CRC) plays an important role in cancer mortality and morbidity. This study examined colorectal tissues for RAS, BRAF, and TP53 gene mutations to assess their value as indicators of outcomes of CRC therapy.
  
  
  METHODS
  DNA was extracted from tissues taken from 165 patients with CRC. RAS gene mutations (exons 2 and 3) were detected by primer extension analysis. BRAF gene mutations (V600E) were detected by high resolution melting (HRM) analysis. TP53 gene mutations (exons 5-8) were detected by direct sequencing.
  
  
  RESULTS
  RAS, BRAF, and TP53 mutations occurred in 36.97% (61/165), 4.24% (7/165), and 37.58% (62/165), respectively. The KRAS mutation is a predictor for poor 5-year survival (p = 0.05), and the co-presence of KRAS and TP53 mutations correlates with lymph node involvement (p = 0.029), tumor stage (p = 0.029), and poor survival (p = 0.021). Multivariate analysis adjusted for tumor size, histologic grade, lymph node metastasis, sex, and age also indicated that KRAS mutations correlate significantly with overall survival (p = 0.036).
  
  
  CONCLUSIONS
  The KRAS mutation is not present in about one-third of CRC patients, and therefore other gene mutations need to be investigated to better understand the molecular mechanisms of CRC and its treatment.
authors.affiliation: Epigenome Research Center, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Ya-Sian
authors.initials: YS
authors.lastname: Chang
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Chang
authors.forename: Kun-Tu
authors.initials: KT
authors.lastname: Yeh
authors.forename: Tsai-Hsiu
authors.initials: TH
authors.lastname: Lin
authors.forename: Jan-Gowth
authors.initials: JG
authors.lastname: Chang
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015995:Prevalence; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012307:Risk Factors; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D018631:ras Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D005819:Genetic Markers; D016159:Tumor Suppressor Protein p53; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D018631:ras Proteins