title: Association of right-sided tumors with high thymidine phosphorylase gene expression levels and the response to oral uracil and tegafur/leucovorin chemotherapy among patients with colorectal cancer.
abstract: OBJECTIVE
  To identify useful predictive factors for the response to 5-fluorouracil (5-FU)/leucovorin (LV) and oral uracil and tegafur (UFT)/LV chemotherapy among patients with colorectal cancer, we investigated the association between the gene expression levels of pyrimidine and folate metabolism-related enzymes in colorectal cancer (CRC) tissues and the response to UFT/LV neoadjuvant chemotherapy.
  
  
  METHODS
  The subjects were 76 CRC patients who were scheduled to undergo surgery. UFT (300 mg/m(2)/day) and LV (75 mg/body/day) were administered for 2 weeks before surgery. Biopsy samples were endoscopically obtained before drug administration. The gene expression levels of 14 genes in the biopsy samples were quantitatively evaluated using a real-time polymerase chain reaction (RT-PCR) assay.
  
  
  RESULTS
  Fifteen patients (19.7 %) with marked pathological regression were judged to be responders. Thymidine phosphorylase (TP) gene expression levels among the responders were significantly higher than those among the non-responders. Right-sided tumors with high TP gene expression levels were associated with a significantly higher response rate to UFT/LV chemotherapy than left-sided tumors.
  
  
  CONCLUSIONS
  TP gene expression levels in primary CRC tissues and the primary tumor site may be useful predictors of the efficacy of oral UFT/LV chemotherapy.
authors: Department of Surgery, Tokai University School of Medicine, Kanagawa 259-1193, Japan. sadahiro@is.icc.u-tokai.ac.jp
authors: Sotaro
authors: S
authors: Sadahiro
authors: Toshiyuki
authors: T
authors: Suzuki
authors: Akira
authors: A
authors: Tanaka
authors: Kazutake
authors: K
authors: Okada
authors: Hideki
authors: H
authors: Nagase
authors: Junji
authors: J
authors: Uchida
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D056726:Genetic Association Studies; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D005641:Tegafur / Q000008:administration & dosage; D013939:Thymidine Phosphorylase / Q000235:genetics*; D014498:Uracil / Q000008:administration & dosage
chemical_list: D005641:Tegafur; D014498:Uracil; C543750:TYMP protein, human; D013939:Thymidine Phosphorylase; D002955:Leucovorin