Comparative Expression of MDM2, SOX2, and Ki-67 in Oral and Cutaneous Lichen Planus: Implications for Malignant Potential

Background and Aim: Oral lichen planus (OLP) is a chronic inflammatory disease that can show potential for malignant transformation, unlike cutaneous lichen planus (CLP). The exact molecular reasons behind this difference are not well known. This study aimed to evaluate the expression of 3 biomarkers namely MDM2, SOX2, and Ki-67 in OLP and CLP to assess their relationship with cell proliferation and possible malignant potential. Methods: This retrospective study was carried out at Sina Hospital in Tabriz, Iran, from April 2022 to June 2023. Fifty paraffin-embedded tissue samples were analyzed, including 25 oral and 25 cutaneous lichen planus cases. Sections were stained immunohistochemically for MDM2, SOX2, and Ki-67. Two pathologists, blinded to patient information, evaluated the slides. Expression was classified as negative, low, or high. Data were analyzed in SPSS version 26 using descriptive statistics and Fisher’s Exact Test, with a P -value ⩽ .05 considered significant. Results: In CLP, all samples were negative for Ki-67, while SOX2 and MDM2 were positive at low levels in only 8% of cases. In OLP, Ki-67 was low in 16%, SOX2 in 20%, and MDM2 was high in 40% of samples. A significant correlation among the 3 markers was seen in OLP ( P < .001), but not in CLP. SOX2 expression differed significantly between erosive and non-erosive OLP ( P = .047). Conclusion: OLP, especially its erosive form, shows higher molecular activity compared with CLP. The coordinated expression of MDM2, SOX2, and Ki-67 supports their role in cell proliferation and malignant potential. MDM2, in particular, may serve as an early indicator for identifying OLP cases at higher risk of malignant transformation.