title: Polymorphisms in ERCC1, GSTs, TS and MTHFR predict clinical outcomes of gastric cancer patients treated with platinum/5-Fu-based chemotherapy: a systematic review.
abstract: BACKGROUND
  Despite genetic polymorphism in response to platinum/5-Fu chemotherapy in gastric cancer (GC) has been studied, data reported so far are conflicting and critical consideration is needed before translation to the treatment of GC.
  
  
  METHODS
  We performed a meta-analysis by using 20 eligible studies to examine polymorphisms of ERCC1, GSTs, TS and MTHFR in predicting clinical outcomes (response rate, overall survival and toxicity) of GC patients treated with platinum/5-Fu-based chemotherapy. The association was measured using random/fixed effect odds ratios (ORs) or hazard ratios (HRs) combined with their 95% confidence intervals (CIs) according to the studies' heterogeneity. Statistical analysis was performed with the software STATA 9.0 package.
  
  
  RESULTS
  No significant association was found between response rate and genetic polymorphism in TS, MTHFR, ERCC1, GSTM1 and GSTP1. However, response rate was higher in GSTT1 (+) genotype compared with GSTT1 (-) genotype (T-/T+: OR=0.67, 95% CI: 0.47-0.97). With regard to long term outcomes, we could observe a significant longer overall survival in TS 3R/3R [(2R2R+2R3R)/3R3R: HR=1.29, 95% CI: 1.02-1.64] and GSTP1 GG/GA [(GG+AG)/AA: HR=0.51, 95% CI: (0.39, 0.67)] genotypes. In addition, significant association was demonstrated between toxicity and genetic polymorphism in TS, MTHFR and GSTP1 in included studies.
  
  
  CONCLUSIONS
  Polymorphisms of ERCC1, GSTs, TS and MTHFR were closely associated with clinical outcomes of GC patients treated with platinum/5-Fu-based chemotherapy. Studies with large sample size using the method of multi-variant analyses may help us to give more persuasive data on the putative association in future.
authors.affiliation: Department of Gastrointestinal Surgery, The First Affiliated Hospital of Guangxi Medical University, 6 Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Jun-qiang
authors.initials: JQ
authors.lastname: Chen
authors.forename: Jin-lu
authors.initials: JL
authors.lastname: Liu
authors.forename: Xin-gan
authors.initials: XG
authors.lastname: Qin
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004720:Endonucleases / Q000235:genetics*; D005472:Fluorouracil / Q000627:therapeutic use*; D056726:Genetic Association Studies; D006801:Humans; D027361:Organic Anion Transporters / Q000235:genetics*; D017671:Platinum Compounds / Q000627:therapeutic use*; D011110:Polymorphism, Genetic; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality; D013940:Thymidylate Synthase / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D004720:Endonucleases; D005472:Fluorouracil; D027361:Organic Anion Transporters; D017671:Platinum Compounds; D013940:Thymidylate Synthase; C487009:SLCO6A1 protein, human; C071447:ERCC1 protein, human