抄録
The purpose of this study was to examine clinical risk factors of oral leukoplakia that were associated with malignant transformation. A total of 512 patients (554 lesions) with clinical and histopathological diagnoses of oral leukoplakia who presented at our department from 2001 through 2010 were retrospectively studied. They consisted of 278 males and 234 females 11 to 84 years of age (median, 61 years). The mean follow-up was 36 months. The sites of oral leukoplakia included the tongue (176 lesions), gingiva (219 lesions), buccal mucosa (76 lesions), hard palate (50 lesions), soft palate (21 lesions), lips (7 lesions), and floor of the mouth (5 lesions). Squamous cell carcinoma developed in 13 of the 512 patients during follow-up. The development occurred after a mean period of 39 months (range, 9 to 91 months). The sites of malignant transformation included the ventral aspect of the tongue (10 lesions), gingiva (1 lesion), buccal mucosa (1 lesion), and soft palate (1 lesion). In 9 of these 13 malignant lesions, the clinical type of oral leukoplakia was non-homogeneous. The degree of epithelial dysplasia was none (2 lesions), mild (5 lesions), or moderate (6 lesions). On univariate analysis, site, clinical type, and treatment significantly correlated with malignant transformation. On multivariate analysis, these 3 factors retained their statistical significance. The cumulative malignant transformation rate was 5.6% at 5 years and 8.7% at 10 years.
