Background: Oral lichen planus (OLP) is a potentially malignant oral disorder that affects 0.5-2% of the general population with a malignant transformation rate of around 1.1%. Malignant transformation is characterized by the increased proliferation of basal layer cells under the influence of biomarkers released from the inflammatory infiltrate. This study was conducted to assess the expression of biomarkers in OLP and their possible predictive value for malignant transformation of these lesions.
Methods: A search for studies on tumor biomarkers in OLP was performed in the following databases: PubMed (MEDLINE, Cochrane Library), Web of Science, and Scopus. Data were analyzed using the statistical software RevMan 5.4 (The Cochrane Collaboration, Oxford, UK). For continuous outcomes, the estimates of effects of an intervention were expressed as mean differences (MD) using the inverse variance (IV) method, and for dichotomous outcomes, the estimates of effects of an intervention were expressed as odds ratios (OR) using Mantel-Haenszel (M-H) method, all with 95% confidence intervals.
Results: A total of 30 studies were included in this meta-analysis. OLP patients compared to controls without the disease had a significantly higher expression of mutated p53 protein (P<0.001), Ki-67 antigen (P<0.001), p16 protein (P<0.001), and cell proliferation nuclear antigen (PCNA) (P=0.04), but not blc-2 protein. In contrast, OLP patients showed 3.71 times higher probability of bcl-2 protein detection (P=0.01).
Conclusions: The expression of tumor biomarkers in OLP suggests the potentially malignant nature of some of these lesions