The effect of retinoids on premalignant oral lesions: Focus on topical therapy

BACKGROUND. Retinoids have been studied as chemopreventive treatment for patients with oropharyngeal carcinoma. Vitamin A modulates growth and differentiation of cells, and its deficiency enhances susceptibility to carcinogenesis. The chemopreventive mechanism of action of vitamin A is discussed, and a review of clinical results and side effects of the systemic use of vitamin A is included. The objective of the current report was to review the possible role of topical vitamin A and vitamin A derivatives in the management of patients with oral lesions with a risk of transformation to carcinoma. METHODS: A Medline search was conducted and references identified within the identified papers were also reviewed. RESULTS. Only four studies using topical vitamin A for patients with oral leukoplakia have been reported. A complete response was achieved in 10-27% of patients, and a partial response was achieved in 54-90% of patients; however, recurrence of leukoplakia was reported after withdrawing the medication in approximately 50% of patients. The side effects of the topical use were minimal. CONCLUSIONS. Although the direct application of higher concentrations of retinoic acid results in suppression of oral leukoplakias only, its use in the treatment of patients with recurrent and persistent lesions may be justified for controlling lesions that otherwise may progress. Further controlled clinical studies are needed.