RESUMO
BACKGROUND: This systematic review and meta-analysis qualitatively and quantitatively analyzes the current evidence on the implications of p53 upregulation in oral lichen planus (OLP) assessed by immunohistochemical techniques, in order to identify molecular mechanisms involved in the behavior of OLP as an oral potentially malignant disorder. MATERIAL AND METHODS: We searched MEDLINE/PubMed, Embase, Web of Science and Scopus for studies published before February-2024. We critically assessed the methodological quality of primary-level studies and performed meta-analyses. RESULTS: Twenty-four individual studies met the inclusion criteria, comprising 721 OLP samples, in which the expression of p53 was analyzed through immunohistochemistry. Most OLP displayed p53 protein upregulation (pooled proportion [PP]= 66.76%, 95%CI=54.84-77.76). Regarding the magnitude of association analysis, oral squamous cell carcinoma (OSCC) cases showed a significantly higher frequency according to p53 expression in comparison to OLP (OR=2.79, 95%CI=1.84-4.24; p<0.001); while, OLP exhibited a significantly higher frequency for p53 expression in comparison to healthy controls (OR=5.70, 95%CI=2.90-11.19; p<0.001). CONCLUSIONS: In conclusion, the present study demonstrates the frequent p53 protein upregulation in patients with OLP, which is probably indicating an antitumor response in an epithelium whose cells are under cellular stress and at risk of cancer.