title: Pattern of expression of cyclooxygenase-2 in malignant transformation of sinonasal inverted papilloma.
abstract: OBJECTIVE
  Cyclooxygenases (COXs) are enzymes that catalyze the conversion of arachidonic acid to prostaglandins. Many studies have suggested that COX-2, the inducible form of COX, is important in carcinogenesis. However, little is known about the pattern of expression of COX-2 in a multistep process of malignant transformation of sinonasal inverted papilloma (IP). In this study, we investigated COX-2 expression in IPs, IPs with dysplasia, IPs with squamous cell carcinoma (SCC), and primary SCCs of sinonasal tract.
  
  
  METHODS
  A retrospective study was conducted.
  
  
  METHODS
  The setting was a tertiary care referral center.
  
  
  METHODS
  The expression of COX-2 was evaluated by immunohistochemistry in 56, 7, 18, and 17 cases of IPs, IPs with dysplasia, IPs with SCC, and primary SCCs, respectively. Furthermore, we investigated the possible correlation between the expression of COX-2 and clinicopathologic variables in patients with IPs with SCC and primary SCC patients.
  
  
  RESULTS
  Positive immunoreactivity for COX-2 was observed in 3 (5.4%) of 56 IPs, 7 (38.9%) of 18 IPs with SCC, and 7 (41.2%) of 17 primary SCCs, whereas it was not observed in IPs with dysplasia. The percentage of tumors with COX-2-positive immunostaining was significantly higher in IPs with SCC and primary SCCs compared with benign IPs. There was no significant correlation between the expression of COX-2 and clinicopathologic variables, such as tumor stage, histologic differentiation, and the proportion of malignant areas in patients with IPs with SCC.
  
  
  CONCLUSIONS
  Cyclooxygenase-2 may play an important role in the process of malignant transformation from IP to SCC.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Chungnam National University, Daejeon, South Korea.
authors.forename: Gun-Ho
authors.initials: GH
authors.lastname: Lee
authors.forename: Yeo-Hoon
authors.initials: YH
authors.lastname: Yoon
authors.forename: Yong Min
authors.initials: YM
authors.lastname: Kim
authors.forename: Min-Kyung
authors.initials: MK
authors.lastname: Yeo
authors.forename: Zhe Long
authors.initials: ZL
authors.lastname: Liang
authors.forename: Jin-Man
authors.initials: JM
authors.lastname: Kim
authors.forename: Ki-Sang
authors.initials: KS
authors.lastname: Rha
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D002471:Cell Transformation, Neoplastic; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018308:Papilloma, Inverted / Q000201:enzymology* / Q000473:pathology; D010255:Paranasal Sinus Neoplasms / Q000201:enzymology* / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2