- Methods: 101 patients with histologically confirmed mild or moderate OED were included in the present study. Baseline information of p16 methylation status of the OED lesions from 93 cases was obtained by methylation-specific PCR. Progression of the OEDs lesions was examined in 78 cases histologically during the 45.8 months double-blind followup survey (78/93). The association between p16 methylation and progression of OED was analyzed with SPSS13.0 software. All P-values were two-sided.