title: Orotate phosphoribosyltransferase gene polymorphism predicts toxicity in patients treated with bolus 5-fluorouracil regimen.
abstract: OBJECTIVE
  We investigated whether the determination of orotate phosphoribosyltransferase (OPRT) and thymidylate synthase (TYMS) polymorphisms could predict the toxicity of 5-fluorouracil (5-FU) in colorectal cancer patients.
  
  
  METHODS
  The determination of OPRT and TYMS genotypes were done in genomic DNA extracted from blood by PCR amplification in 69 patients treated with bolus 5-FU as adjuvant chemotherapy. Associations between these polymorphisms and toxicity were evaluated retrospectively.
  
  
  RESULTS
  The Ala allele in OPRT Gly213Ala polymorphism and the two tandem repeats (2R) in TYMS promoter polymorphism were associated with grade 3 to 4 neutropenia and diarrhea. The multivariate logistic regression models revealed that only TYMS promoter polymorphism had an independent value to predict grade 3 to 4 neutropenia [odds ratio, 19.2 for patients with the 2R allele compared with patients with homozygous with the three repeat (3R) alleles], whereas both OPRT and TYMS promoter polymorphisms were independent predictive factors for grade 3 to 4 diarrhea (odds ratio, 13.3 for patients with the Ala allele compared with patients in the Gly/Gly genotype and 11.1 for patients with the 2R allele compared with patients in the 3R/3R genotype). A significant difference was observed in the time to onset of severe toxicity, defined as grade 4 neutropenia and/or grade 3 to 4 gastrointestinal toxicities according to OPRT and TYMS promoter polymorphisms.
  
  
  CONCLUSIONS
  OPRT Gly213Ala polymorphism seems to be a useful marker for predicting toxicity to bolus 5-FU chemotherapy. Prospective translational treatment trials including larger number of patients are needed to confirm our results.
authors.affiliation: Department of General and Digestive Surgery, Saitama Medical School, Iruma, Saitama, Japan. wataru@saitama-med.ac.jp
authors.forename: Wataru
authors.initials: W
authors.lastname: Ichikawa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Takahashi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Suto
authors.forename: Yasutsuna
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Renzo
authors.initials: R
authors.lastname: Hirayama
mesh_terms: D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D015971:Gene Expression Regulation, Enzymologic; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009962:Orotate Phosphoribosyltransferase / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic; D011237:Predictive Value of Tests; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012189:Retrospective Studies; D013940:Thymidylate Synthase / Q000235:genetics / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D012333:RNA, Messenger; D013940:Thymidylate Synthase; D009962:Orotate Phosphoribosyltransferase; D005472:Fluorouracil