Overexpression of cyclooxygenase-2 as a biomarker in different subtypes of the oral lichenoid disease

Objective. Oral lichenoid disease (OLD) includes a number of chronic inflammatory processes including oral lichen planus (OLP) and oral lichenoid lesions (OLL) with controversial diagnosis and prognosis. Cyclooxygenase-2 (COX-2) is a key enzyme for inflammatory processes and cellular proliferation. Its overexpression in some premalignant chronic inflammatory diseases and malignant neoplasias could point to its potential as a prognostic factor. The aim of this study was to analyze the COX-2 expression in different subtypes of OLD because of its potential to be a marker of altered behavior. Study design. Forty-four samples from OLD patients were studied (30 females and 14 males) and classified according to their clinical (C1: only papular lesions/C2: papular and other lesions) and histological features (HT: OLP typical/HC: OLP compatible) according to published criteria. Standard immunohistochemical procedure was performed for COX-2 expression and a comparative and descriptive statistical analyses were performed. Results. Epithelial COX-2 overexpression was observed in 24 (54.5%) cases (C1: 13 [54.2%]/C2: 11 [45.8%], HT: 9 [37.5%]/HC: 15 [62.5%], P = .032). Inflammatory COX-2 overexpression was observed in 14 (31.8%) cases (C1: 6 [42.9%]/C2: 8 [57.1%], HT: 4 [28.6%]/HC: 10 [71.4%], P = .032). Conclusion. Differences in COX-2 expression in subtypes of OLD may distinguish cases with a higher premalignant potential. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:738-743)