ABSTRACT
Statement of the Problem: Lichen planus is a mucocutaneous disease that is relatively common in middle aged individuals. Some studies have shown that oral lichen planus has a potential to progress to squamous cell carcinoma.p21 is a cyclin-dependent kinase inhibitor that regulates the cell cycle, thus it acts as an inhibitor in cell proliferation
Purpose: This study was aimed to evaluate and compare the immunostaining of p21 [as a proliferation inhibitory factor] in oral lichen planus [OLP] and oral squamous cell carcinoma [OSCC]
Materials and Method: In this descriptive cross-sectional study, p21expression was investigated in 24 samples of oral lichen planus [OLP], 24 samples of oral squamous cell carcinoma [OSCC] and 24 samples of oral epithelial hyperplasia [OEH] by employing immunohistochemical staining
Results: The mean percentage of p21-positive cells in OSCC [54.5 +/- 6.6] was significantly higher than that in OLP [32.8 +/- 6.08] and OEH [9.4 +/- 3.8]. Moreover, OLP samples expressed p21 significantly higher than the OEH. Kruskal Wallis test revealed a statistically significant difference between the groups regarding the intensity of staining [p< 0.001]
Conclusion: According to the findings of this study, the expression of p21 might be related to the potential carcinogenic transformation of lichen planus to SCC. Therefore, continuous follow-up periods for OLP are recommended for diagnosis of the malignant transformations in early stages