title: The enhanced expression of the matrix metalloproteinase 9 in nasal NK/T-cell lymphoma.
abstract: BACKGROUND
  Nasal NK/T cell lymphoma is an aggressive disease and has a poor prognosis. Nasal NK/T cell lymphoma is refractory to conventional chemotherapy and has strong tendency of widespread relapse or dissemination into distant sites.
  
  
  METHODS
  We immunohistochemically studied nasal NK/T-cell lymphoma to elucidate the unique characteristics of nasal NK/T-cell lymphoma, such as its higher metastatic tendency and its vast necrosis which leads to destruction of the involved tissues. The expression of P-glycoprotein and MMP-9 was evaluated in the 20 patients with nasal NK/T-cell lymphoma and 25 with nasal non-NK/T-cell lymphoma and the relationship between expression of these proteins and clinical results were analyzed in this report.
  
  
  RESULTS
  Overall 5-year survival rates for patients with nasal NK/T cell lymphoma, and nasal non-NK/T cell lymphoma were 51%, and 84%. Distant involvement free 5-year survival rates for patients with nasal NK/T cell lymphoma, and nasal non-NK/T cell lymphoma were 53%, and 79%. Overall positivity for P-glycoprotein was observed in 10 of 19 patients with NTL and in 13 of 23 patients with non-NTL. When the overall survival rate was compared between patients with P-glycoprotein positive and negative, there was no difference between them. Sixteen of the 19 patients with nasal NK/T cell lymphoma expressed MMP-9. In contrast, only 8 of the 22 patients with nasal non-NK/T cell lymphoma expressed MMP-9. Distant involvement free 5-year survival rates for patients with MMP-9 negative, and MMP-9 positive were 92%, and 61%, respectively. The difference was statistically significant (p = 0.027).
  
  
  CONCLUSIONS
  Positive immunoreactivity for P-glycoprotein was not an independent prognostic factor in nasal NK/T-cell lymphomas, which stresses the importance of exploring other mechanisms of drug resistance. The strong expression of MMP-9 is uniquely characteristic of nasal NK/T cell lymphoma and may contribute to its strong tendency to disseminatate and the extensive necrosis which is always seen. However, our results are based on univariate comparisons, and as such, should be viewed with some caution.
authors: Department of Radiology, Sapporo Medical University, School of Medicine, Sapporo, Japan. sakatako@sapmed.ac.jp
authors: Koh-ichi
authors: K
authors: Sakata
authors: Masanori
authors: M
authors: Someya
authors: Mutsuko
authors: M
authors: Omatsu
authors: Hiroko
authors: H
authors: Asanuma
authors: Tadashi
authors: T
authors: Hasegawa
authors: Shingo
authors: S
authors: Ichimiya
authors: Masato
authors: M
authors: Hareyama
authors: Tetsuo
authors: T
authors: Himi
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D054391:Lymphoma, Extranodal NK-T-Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D009296:Nasal Cavity / Q000473:pathology*; D009669:Nose Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D015996:Survival Rate
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D020780:Matrix Metalloproteinase 9