Bcl-2 expression and its possible influence on malignant transformation of oral lichen planus.

Abstract The aim of this study was to investigate the malignant potential of oral lichen planus (OLP) on the basis of the expression of the Bcl-2 marker in healthy individuals (H), patients with OLP and patients with squamous cell carcinoma (SCC), and to establish potential interdependence between expression of Bcl-2 and the different clinical and histopathological parameters in H, OLP, and SCC. Immunohistochemistry for Bcl-2 was carried out using an avidin-biotin peroxidase complex method. Tissue sections were treated with mouse monoclonal antibody against Bcl-2 (124, DAKO A/S, Denmark; dilution 1/100). Immunohistochemical parameters measured included total tissue area, total stained area and intensity of stain. Keratinocytes were not Bcl-2 positive in H and were sparsely positive in OLP. The number of lymphocytes stained with Bcl-2 was significantly lower in H as compared to patients with SCC and OLP. Bcl-2 staining was weak to moderate in OLP, and moderate to intense in SCC. Bcl-2-positive lymphocytes were more expressed in older OLP patients (>55 years), and in OLP specimens with orthokeratinized epithelium, less developed acanthosis and highest grade of lymphocyte expression. Bcl-2 may not serve as a prognostic biomarker in oral cancer development from OLP, but it could help in selecting patients with higher need of follow up to prevent malignancy.