Development of squamous cell carcinoma from pre-existent oral leukoplakia: with respect to treatment modality.

The present study was undertaken in order to determine whether surgical treatment of oral leukoplakia reduces the risk of the subsequent development of carcinoma. This study included 142 patients with oral leukoplakia who received or did not receive surgical treatment. All subjects were followed-up for more than 6 months with a mean follow-up period of 4 years. Malignant transformation rate was lower among patients who received surgical excision (1/75) than among those who did not receive surgical treatments (4/51). However, the malignant transformation rates were high in patients who received cryosurgery (3/12) or cryosurgery plus surgical excision (1/4). There was no obvious relation between the grade of epithelial dysplasia and the rate of malignant transformation. Our results suggest that surgical excision of oral leukoplakia may reduce the risk of the subsequent development of carcinoma.