title: Raised levels of plasma big endothelin 1 in patients with colorectal cancer.
abstract: BACKGROUND
  The aim was to assess the role of plasma Big Endothelin (ET) 1 levels as a marker of disease presence and stage in colorectal adenocarcinoma.
  
  
  METHODS
  Big ET-1 was measured in the plasma of 37 patients with colorectal cancer. Preoperative systemic plasma levels of Big ET-1 in patients with cancer were compared with levels in 20 age- and sex-matched controls. Portal plasma samples were collected at operation in addition to peripheral venous samples. Immunohistochemical staining for Big ET-1 was performed on a selection of primary tumour specimens and liver metastases.
  
  
  RESULTS
  Median (range) preoperative systemic plasma levels of Big ET-1 were significantly higher in patients with cancer than in controls (1.0 (0.3-9.7) versus 0.2 (0.0-6.0) fmol/ml; P = 0.0001). Intraoperative portal plasma levels of Big ET-1 were significantly higher in patients with Dukes' 'D' disease than in patients with Dukes' A, B and C disease (2.1 (1.4-10.0) versus 1.2 (0.3-6.6) fmol/ml; P = 0. 01). Similarly, systemic plasma levels were significantly higher in patients with Dukes' 'D' disease than in those with localized disease (1.9 (1.2-9.7) versus 1.2 (0.2-8.3) fmol/ml; P = 0.01). The presence of microvascular invasion in the tumour specimens was associated with a significantly raised portal plasma level of Big ET-1 (1.6 (1.5-2.1) versus 1.1 (0.8-1.3) fmol/ml; P = 0.04). Immunohistochemistry localized Big ET-1 to the cancer epithelial cells.
  
  
  CONCLUSIONS
  The plasma level of Big ET-1 is significantly raised in patients with colorectal cancer. Patients with liver metastases have significantly higher levels than those with localized disease.
authors.affiliation: University Department of Surgery and Department of General and Gastrointestinal Surgery, Leicester Royal Infirmary, Leicester LE2 7LX, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Simpson
authors.forename: T
authors.initials: T
authors.lastname: Dickinson
authors.forename: K E
authors.initials: KE
authors.lastname: Porter
authors.forename: N J
authors.initials: NJ
authors.lastname: London
authors.forename: D M
authors.initials: DM
authors.lastname: Hemingway
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019332:Endothelin-1; D016232:Endothelins / Q000097:blood*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011498:Protein Precursors / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors