title: Expression of matrix metalloproteinase-9 in head and neck squamous cell carcinoma: a potential marker for prognosis.
abstract: OBJECTIVE
  Previous studies have shown that matrix metalloproteinase-9 (MMP-9) is expressed in malignant head and neck squamous cell carcinoma. The prognostic role of MMP-9 is still unclear. The aim of this study was to investigate the role of MMP-9 immunoreactive protein as a prognostic marker for survival in head and neck squamous cell carcinoma.
  
  
  METHODS
  Overexpression of the immunoreactive protein for MMP-9 was evaluated in tissue sections of 74 primary head and neck carcinomas with a monoclonal antibody using a biotin-streptavidin immunohistochemical staining method. The staining results were compared with the clinical data and to the patients' outcome.
  
  
  RESULTS
  Positive immunostaining for MMP-9 was observed in 82% of the head and neck carcinomas, 39% of the cases being extensively positive. MMP-9 protein expression was independent of the stage or the grade of the tumor. The expression of MMP-9 was prognostic for shortened survival, the 5-year cause-specific survival being 45% in MMP-9 positive cases, and 92% in cases negative for MMP-9 (P = 0.013). MMP-9 positivity also correlated to the relapse-free survival (P = 0.019). At the 5-year follow-up, the cumulative relapse-free survival rate was 79% for patients with MMP-9-negative tumor and 42% for the patients with positive immunostaining for MMP-9. High expression of MMP-9 seemed to be linked with more aggressive relapses, appearing in 33% of the cases in local relapses, in 52% of cases with lymph node relapses, and in 60% of the cases with hematogenic relapses.
  
  
  CONCLUSIONS
  This is the first study with a long follow-up showing that the immunoreactive protein of MMP-9 in head and neck carcinoma is associated with shortened relapse-free and cause-specific survival, suggesting that MMP-9 has a role in tumor progression of head and neck carcinomas, as well as in estimation of the prognosis of these diseases.
authors.affiliation: Department of Oncology and Radiotherapy, Oulu University Hospital, Oulu, Finland.
authors.forename: Henni
authors.initials: H
authors.lastname: Ruokolainen
authors.forename: Paavo
authors.initials: P
authors.lastname: Pääkkö
authors.forename: Taina
authors.initials: T
authors.lastname: Turpeenniemi-Hujanen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000473:pathology*; D005260:Female; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012737:Sex Factors; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D020780:Matrix Metalloproteinase 9