title: Prognostic significance of K-ras mutations in pancreatic cancer: a meta-analysis.
abstract: BACKGROUND
  K-ras gene mutations are common in patients with pancreatic cancer (PC); however, their prognostic value for PC remains inconclusive. This meta-analysis was performed to quantitatively evaluate the association between K-ras mutations and survival in patients with pancreatic cancer.
  
  
  METHODS
  We performed a comprehensive search of electronic sources including MEDLINE (via PubMed), Web of Science, and the Cochrane Library. The search covered a publication period from inception to November 2015.
  
  
  RESULTS
  Seventeen studies with a total of 2249 patients with pancreatic cancer were included in the tissue detection of this study. The meta-analysis indicated a significant association between mutant K-ras genes and overall survival (OS) (HR = 1.51, 95% CI 1.32-1.72, P < 0.001). Moreover, further subgroup analyses by ethnicity, publication year, therapy method, cancer resectability, and gene detection method all revealed that pancreatic cancer patients with the K-ras mutation had significantly poorer OS (P < 0.05). And results from four studies with 225 patients focused on plasma K-ras mutations enhanced such association (HR = 2.23, 95% CI 1.69-2.95, P < 0.001).
  
  
  CONCLUSIONS
  As a prediction of poor prognosis, the detection of K-ras mutations may be a useful prognostic factor for pancreatic cancer patients.
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China.
authors.forename: Lian-yuan
authors.initials: LY
authors.lastname: Tao
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China.
authors.forename: Ling-fu
authors.initials: LF
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China. xiudianrong123@sina.com.
authors.forename: Dian-rong
authors.initials: DR
authors.lastname: Xiu
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China.
authors.forename: Chun-hui
authors.initials: CH
authors.lastname: Yuan
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China.
authors.forename: Zhao-lai
authors.initials: ZL
authors.lastname: Ma
authors.affiliation: Department of General Surgery, Peking University Third Hospital, No. 49, Hua Yuan North Rd, Hai Dian District, Beijing, 100191, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D006801:Humans; D009154:Mutation / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D016133:Polymerase Chain Reaction; D011379:Prognosis; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)
keywords: K-ras; Meta-analysis; Pancreatic cancer; Prognosis