The expression of laminin-5 in severe dysplasia/carcinoma in situ and early invasive squamous cell carcinoma: An immunohistochemical study

Aim. The objective of the present study was to detect the immunohistochemical localization of laminin-5 in the subepithelial basement membrane and to investigate the integrity of the basement membrane in cases of severe dysplasia/carcinoma in situ and early invasive squamous cell carcinoma. Methods. Tissue samples of 55 filed (25-early invasive squamous cell carcinoma; 25-severe dysplasia/carcinoma in situ;5-normal buccal mucosa as controls) cases were collected from the archives of Oral Pathology Department. Routine staining and Immunostaining for laminin-5 (Biogenex) was carried out on the sections. The immunohistochemical localization and integrity of the basement membrane protein isoform laminin-5 was studied in formalin fixed paraffin embedded sections of severe dysplasia/CIS and early invasive squamous cell carcinoma (EISCC). Chi square test was used for statistical analysis. P values <0.05 were considered statistically significant. Results. The immunostaining of laminin-5 as observed under light microscope ranged from continuous to complete absence. The laminin-5 staining pattern was more often continuous in severe dysplasia/CIS and discontinuous or absent in EISCC. A statistical comparision between different scores of laminin-5 staining in severe dysplasia/CIS and early invasive squamous cell carcinoma showed a highly significant 'P' value (0.0001). Conclusion. The status of basal lamina, laminin-5 may provide additional and relevant information about invasive potential of dysplasias. Hence the study of laminin-5 immunohistologically can be regarded as an adjunct to distinguish severe dysplastic lesions from early oral invasive carcinoma.