title: Can K-ras gene mutation be utilized as prognostic biomarker for colorectal cancer patients receiving chemotherapy? A meta-analysis and systematic review.
abstract: BACKGROUND
  K-ras gene mutations were common in colorectal patients, but their relationship with prognosis was unclear.
  
  
  OBJECTIVE
  Verify prognostic differences between patient with and without mutant K-ras genes by reviewing the published evidence.
  
  
  METHODS
  Systematic reviews and data bases were searched for cohort/case-control studies of prognosis of colorectal cancer patients with detected K-ras mutations versus those without mutant K-ras genes, both of whom received chemotherapy. Number of patients, regimens of chemotherapy, and short-term or long-term survival rate (disease-free or overall) were extracted. Quality of studies was also evaluated.
  
  
  RESULTS
  7 studies of comparisons with a control group were identified. No association between K-ras gene status with neither short-term disease free-survival (OR=1.01, 95% CI, 0.73-1.38, P=0.97) nor overall survival (OR=1.06, 95% CI, 0.82-1.36, P=0.66) in CRC patients who received chemotherapy was indicated. Comparison of long-term survival between two groups also indicated no significant difference after heterogeneity was eliminated (OR=1.09, 95% CI, 0.85-1.40, P=0.49).
  
  
  CONCLUSIONS
  K-ras gene mutations may not be a prognostic index for colorectal cancer patients who received chemotherapy.
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China ; Institute of Digestive Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Yuan-Yi
authors.initials: YY
authors.lastname: Rui
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.forename: Zong-Guang
authors.initials: ZG
authors.lastname: Zhou
authors.forename: Cun
authors.initials: C
authors.lastname: Wang
authors.forename: Lie
authors.initials: L
authors.lastname: Yang
authors.forename: Yong-Yang
authors.initials: YY
authors.lastname: Yu
authors.forename: Hai-Ning
authors.initials: HN
authors.lastname: Chen
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000401:mortality; D006801:Humans; D009154:Mutation / Q000235:genetics*; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D015996:Survival Rate; D018631:ras Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins