Comparative study of E-cadherin expression between reticular, erosive oral lichen planus and lichenoid lesions.

Background: Accurate and early diagnosis of dysplastic lesions is crucial for successful treatment. A decrease in E-cadherin expression has been observed in dysplastic lesions and tumors. Therefore, the aim of this study was to investigate the expression of E-cadherin, a cell membrane adhesive protein involved in tissue structure and differentiation, in oral reticular lichen planus, erosive lichen planus, and lichenoid lesions. Materials and Methods: This descriptive cross-sectional study was conducted on 65 oral samples (20 reticular lichen planus, 20 erosive lichen planus, and 20 lichenoid lesions, with 5 samples of healthy mucosa), to evaluate the expression of E-cadherin using immunohistochemical methods. Data were analyzed using SPSS software (version 25), descriptive statistics, Chi-square tests, and Fisher's exact tests, with a significance threshold set at P < 0.05. Results: The majority of patients were female (72.3%) and primarily in the sixth and seventh decades of life (49.2%). A significant difference was observed between the studied groups regarding staining status (P = 0.038), with erosive lichen planus showing the highest frequency of alterations in E-cadherin expression (45%). In addition, a significant difference was noted between staining status and lesion location (P = 0.004), with the highest frequency of E-cadherin expression changes occurring in buccal mucosal samples (30%). Conclusion: E-cadherin expression in erosive lichen planus is significantly lower than in healthy tissue, reticular lichen planus, and lichenoid lesions. Given the similar reduction observed in squamous cell carcinoma samples, evaluating E-cadherin expression may aid in the early recognition of malignant changes.