title: Expression of thymidylate synthase in liver and lung metastases of colorectal cancer and their matched primary tumours.
abstract: BACKGROUND
  In advanced colorectal cancer (CRC) a low expression of thymidylate synthase (TS) in metastases predicts a higher response to 5-fluorouracil (5-FU). The purpose of this study was to investigate the expression of TS in liver and lung metastases of CRC and their matched primary tumours.
  
  
  METHODS
  Immunohistochemical analysis of TS expression was performed on tissue samples of 48 CRC metastases (liver n=38, lung n=10) and their matched primary tumours (n=45).
  
  
  RESULTS
  There was no significant correlation between TS expression in 33/48 (69%), matched samples of metastases and primary tumours (r=0.02, p=1.0).
  
  
  CONCLUSIONS
  This study indicates that TS expression in liver and lung metastases of CRC does not always reflect the level of TS in their corresponding primary tumours. Therefore, it might not be accurate to solely rely on analyses of TS in the primary tumours to predict the effect of 5-FU-based chemotherapy in metastatic CRC.
authors.affiliation: Department of Oncology, Karolinska University Hospital Solna, Stockholm, Sweden. katarina.ohrling@karolinska.se
authors.forename: Katarina
authors.initials: K
authors.lastname: Ohrling
authors.forename: David
authors.initials: D
authors.lastname: Edler
authors.forename: Marja
authors.initials: M
authors.lastname: Hallström
authors.forename: Peter
authors.initials: P
authors.lastname: Ragnhammar
mesh_terms: D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology* / Q000556:secondary*; D008175:Lung Neoplasms / Q000201:enzymology* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D013940:Thymidylate Synthase / Q000096:biosynthesis*
chemical_list: D013940:Thymidylate Synthase