title: Mutation spectra of RAS gene family in colorectal cancer.
abstract: BACKGROUND
  The clinicopathologic features and frequency of KRAS mutations in colorectal cancer (CRC) patients have been reported; however, the characteristics and impact of NRAS and HRAS mutations on the survival of CRC patients have seldom been addressed.
  
  
  METHODS
  Under institutional review board approval, 1,519 CRC patients who underwent surgery were enrolled. Mutation status of RAS was determined by polymerase chain reaction and mass spectrophotometry.
  
  
  RESULTS
  The frequency of KRAS, NRAS, and HRAS mutations was 39.6%, 4.3%, and 1.7%, respectively. The KRAS mutation was associated with fewer left-sided tumors, fewer poor differentiated tumors, more mucin component, and less lymphovascular invasion. The NRAS or HRAS mutations were not associated with any of the clinicopathologic features examined. After univariate analysis, only NRAS mutation was associated with patients' overall and disease-free survival. However, the association of NRAS with patients' overall and disease-free survival disappeared after stepwise elimination.
  
  
  CONCLUSIONS
  This study demonstrates the clinicopathologic characteristics of CRC patients with RAS mutations. Patients with NRAS mutation tended to have worse outcomes.
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Surgery, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Yu-Yao
authors.initials: YY
authors.lastname: Chang
authors.affiliation: Department of Clinical Pathology, Yang-Ming Campus, Taipei City Hospital, Taiwan.
authors.forename: Pei-Ching
authors.initials: PC
authors.lastname: Lin
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hung-Hsin
authors.initials: HH
authors.lastname: Lin
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Jen-Kou
authors.initials: JK
authors.lastname: Lin
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wei-Shone
authors.initials: WS
authors.lastname: Chen
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Jeng-Kai
authors.initials: JK
authors.lastname: Jiang
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shung-Haur
authors.initials: SH
authors.lastname: Yang
authors.affiliation: Department of Pathology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Wen-Yih
authors.initials: WY
authors.lastname: Liang
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, 11217, No. 201, Section 2, Shipai Road, Taipei, Taiwan; Department of Surgery, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: changsc@vghtpe.gov.tw.
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics*; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics*; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm
keywords: Colorectal cancer; HRAS; KRAS; NRAS; Survival