Cytokeratin expression in oral submucous fibrosis – an immunohistochemical study

Background: Oral submucous fibrosis (OSF) is a pre‐malignant condition caused by habitual use of areca nut, affecting the oro‐pharynx and characterized by progressive fibrosis. Alteration of cytokeratin (CK) expression has been documented in leukoplakia and oral cancer (OC). However, very little is known of CK alterations in OSF. The present study was carried out to characterize the CK profile in OSF and ascertain if this could be used as a surrogate marker for malignant transformation. Methods: Paraffin‐embedded tissues of OSF ( n = 50), normal ( n = 10) and OC ( n = 10) were stained with pancytokeratin (PanCK), high molecular weight cytokeratin (HMWCK), CKs 18, 14, 8, 5, 4 and 1 by immunohistochemistry. Results: Significant difference in the CK staining pattern was seen between normal, OSF and cancer. Significant changes in OSF included increased intensity of staining for PanCK and HMWCK, aberrant expression of CK8 and decreased expression of CKs 5 and 14. Conclusion: Cytokeratin profile of OSF was significantly different from normals for PanCK, HMWCK, CK8, 5 and 14 suggesting their potential to be used as surrogate markers of malignant transformation. Further studies will help in better defining the nature and clinical implications of these alterations.