Comparative Investigation of Cyclin D1 Expression in Oral Lichen Planus and Squamous Cell Carcinoma by Immunohistochemistery Technique

Oral lichen planus (OLP) is suggested as a lesion capable of transforming to oral squamous cell carcinoma (OSCC). However malignancy potential of the lesion and its relationship to OSCC is a matter of controversy. Since uncontrolled cell proliferation is an indicator of malignant transformation, the aim of this study was to compare cyclin D1 expression in OLP and OSCC lesions. In this descriptive-analytical study, cyclin D1 expression among 3 groups of epithelial hyperplasia, OLP and OSCC each having 21 samples was investigated using immunohistochemistry staining through quantitative and semi-quantitative methods. One-way ANOVA, Kruskal Wallis, Mann-Withney and Chi-square were used for statistical analysis. Quantitatively, cyclin D1 expression for epithelial hyperplasia, OLP and OSCC were 13.69±6.00%, 28.38±3.53% and 66.94%±14.49%, respectively. Semi- quantitatively, number of stained cells for epithelial hyperplasia and OLP were less than 35% while for OSCC it was more than 35%. Through quantitative and Semi- quantitative comparison, cyclin D1 expression among the three studied groups overally and either bilaterally was significantly different (P<0.05). The results showed that cell proliferation of OLP significantly was less than that of OSCC suggesting that is no relationship between the two although pre-malignancyability of OLP is not exactly ruled out. It seems that increasing cell proliferation might be related to malignancy transformation of OLP; therefore, continuous follow-up of the lesion is necessary.