title: Plasma glutathione S-transferase P1-1 levels in patients with head and neck squamous cell carcinoma.
abstract: BACKGROUND
  Many tumors contain high amounts of the detoxification enzyme glutathione S-transferase P1-1 (GSTP1-1). Elevated levels of GSTP1-1 have also been detected in serum and plasma from patients with gastrointestinal, lung, or head and neck tumors. The authors of this report evaluated the role of GSTP1-1 as a plasma tumor marker in patients with head and neck squamous cell carcinoma (HNSCC) of the larynx, hypopharynx, or oropharnyx and in patients with benign head and neck lesions (BHNL).
  
  
  METHODS
  GSTP1-1 levels were measured in EDTA plasma combined with ethylenediaminetetraacetic acid using a recently developed sensitive and specific sandwich enzyme-linked immunoadsorbent assay. A normal reference level with an upper limit of 21.8 microg GSTP1-1 per liter of plasma was calculated from results obtained with samples from 230 blood donors.
  
  
  RESULTS
  Median GSTP1-1 levels in samples from 53 patients with oral/oropharyngeal SCC (10.6 microg/L; range, 3.7-46.1 microg/L), 12 patients with hypopharyngeal SCC (11.9 microg/L; range, 5.2-146.6 microg/L), and 28 patients with laryngeal SCC (14.4 microg/L; range, 6.4-141.5 microg/L) were significantly elevated when compared with plasma GSTP1-1 levels in samples from 45 patients with BHNL (8.1 microg/L; range, 3.3-32.3 microg/L; P < 0.0001, P < 0.01, and P < 0.0001, respectively). However, only 6 of 53 patients (11%) with oral/oropharyngeal SCC, 1 of 12 patients (8%) with hypopharyngeal SCC, and 6 of 28 patients (21%) with laryngeal SCC had plasma GSTP1-1 levels above the upper limit of the normal reference level. Thus, only 13 of 93 patients (14%) with HNSCC had elevated plasma GSTP1-1 levels overall. No significant relation between plasma GSTP1-1 levels and TNM classification of the tumors was observed.
  
  
  CONCLUSIONS
  GSTP1-1 is not a suitable plasma tumor marker for HNSCC.
authors.affiliation: Department of Otorhinolaryngology/Head and Neck Surgery, Academic Hospital, University of Maastricht, The Netherlands.
authors.forename: M B
authors.initials: MB
authors.lastname: Oude Ophuis
authors.forename: T P
authors.initials: TP
authors.lastname: Mulder
authors.forename: W H
authors.initials: WH
authors.lastname: Peters
authors.forename: J J
authors.initials: JJ
authors.lastname: Manni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005982:Glutathione Transferase / Q000097:blood*; D006258:Head and Neck Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; D005982:Glutathione Transferase