Is OLP potentially malignant? A clue from ZNF582 methylation

Objective: Whether oral lichen planus (OLP) was potentially malignant remains controversial. Here, we examined associations of ZNF582 methylation (ZNF582^m) with OLP lesions, dysplastic features and squamous cell carcinoma (OSCC). Materials and Methods: This is a case–control study. ZNF582^m was evaluated in both lesion and adjacent normal sites of 42 dysplasia, 90 OSCC and 43 OLP patients, whereas ZNF582^m was evaluated only in one mucosal site of 45 normal controls. High-risk habits affecting ZNF582^m such as betel nut chewing and cigarette smoking were also compared in those groups. Results: OLP lesions showed significantly lower ZNF582^m than those of dysplasia and OSCC. At adjacent normal mucosa, ZNF582^m increased from patients of OLP, dysplasia, to OSCC. In addition, ZNF582^m at adjacent normal sites in OLP patients was comparable to normal mucosa in control group. Dysplasia/OSCC patients with high-risk habits exhibited significantly higher ZNF582^m than those without high-risk habits. However, ZNF582^m in OLP patients was not affected by those high-risk habits. Conclusions: OLP is unlikely to be potentially malignant based on ZNF582^m levels. ZNF582^m may also be a potential biomarker for distinguishing OLP from true dysplastic features and OSCC, and for monitoring the malignant transformation of OLP, potentially malignant disorders with dysplastic features and OSCC.