ABSTRACT Background Oral epithelial dysplasia ( OED ) often precedes oral squamous cell carcinoma ( OSCC ). The aim was to elucidate the risk and time of malignant transformation ( MT ) of OED . Methods Patients diagnosed with OED between 2001 and 2011 in Helsinki and Uusimaa, Finland were included. Kaplan–Meier and Cox proportional hazard analysis factors associated with the MT time. Results Dysplasias of 225 patients (mean age 60.0 years, 51.6% females) were diagnosed as mild (85.8%), moderate (11.6%), or severe (2.7%). MT occurred in 14.7% (51.5% females, 48.5% males) at a median time of 5.5 years ( IQR 1.7–12.5 years). MT occurred in 33.3% of severe ( n = 6), 34.6% ( n = 26) of moderate, and 11.4% ( n = 193) of mild dysplasia. Dysplasia severity was associated with an increased risk for MT . Conclusions MT of OED was 14.7%. The severity of OED is a predictor for MT.
Leino et al. (Thu,) studied this question.