Malignant Transformation of Oral Leukoplakia – An Umbrella Review

Background: Oral leukoplakia (OL) is a potentially malignant disorder with white patches in the oral cavity, carrying a risk of transforming into oral squamous cell carcinoma. Factors such as gender, lesion subtype, and tobacco use influence malignant transformation (MT), but a comprehensive umbrella review of recent data is lacking. Objective: To systematically analyze evidence on the MT of OL, focusing on gender, lesion subtype, and the role of tobacco use and idiopathic factors. Methods: This review analyzed systematic reviews published until August 2024. To identify studies on MT rates in OL, a search was conducted across various databases. The databases used for the study included Embase, PubMed, MEDLINE, Web of Science, and Google Scholar. Data extraction and evaluations of risk of bias were carried out by three independent authors. Results: Eight systematic reviews involving 95,467 patients were included. The pooled MT rate ranged from 3.5% to 43.87%. Higher MT rates were linked to non-homogeneous lesions, larger lesion size, epithelial dysplasia, and tobacco use. Conclusion: This review confirms a higher risk of MT in OL, particularly for non-homogeneous lesions. Smokeless tobacco use with alcohol consumption is a significant risk factor, and further research is needed to identify additional factors and develop gender-specific prevention strategies.