Abstract
CONTEXT: The bcl-2 proto-oncogene was discovered at the chromosomal breakpoint of t (14;18) found in follicular lymphoma. Histological changes in dysplasia are considered the earliest signs preceding the progression into squamous cell carcinoma. Serving as critical regulators of apoptotic pathways, bcl-2 prohibits programmed cell death and subsequently assists in uncontrolled neoplastic growth. SETTINGS AND DESIGN: This study included 48 cases, eight each of epithelial dysplasia and squamous cell carcinoma. Immunohistochemical staining using bcl-2 antibody was performed and different histological parameters were correlated with bcl-2 positive cells in all the cases. MATERIALS AND METHODS: All 3 μm thick sections were stained with bcl-2 antibody. After identifying four representative fields at 40x, their images were obtained for assessment of bcl-2 labelled cells and their intensity along with different histological parameters in all the cases. STATISTICAL ANALYSIS: The differences between different histological parameters were analysed using the Anova test, post hoc test and Bonferroni test. Pearson's Chi-square test was carried out to determine the level of correlation between the bcl-2 positive cells in both epithelial dysplasia and oral squamous cell carcinoma cases. CONCLUSION: Sequential increase in the bcl-2 expression was observed in increasing grades of epithelial dysplasia, whereas bcl-2 expression was significantly decreased in ascending stages of squamous cell carcinoma thus, suggesting a possible role of bcl-2 in disease progression from premalignancy to malignancy.