Retinoid Treatment for Oral Leukoplakia: Current Evidence and Future Development

Oral leukoplakia (OLK) is one of the most common oral potentially malignant disorders (OPMDs). Preventing malignant transformation is the main purpose of OLK treatment. The treatment approaches of OLK include surgery, chemotherapy, and other therapies, such as photodynamic therapy and CO₂ laser. The application of genomic variation-based chemotherapy in OLK deserves further exploration. As chemopreventive drugs, drug resistance and disease recurrence have limited their use in OLK. In this review, we concentrate on the retinoid treatment for OLK, summarizing the current status of retinoids in the treatment of OLK, the mechanism of retinoid action, and the mechanisms of resistance to retinoid therapy, and we highlight the strategies to improve retinoid efficacy in the treatment of OLK, such as the combination of retinoids and epigenetic regulators or metabolism-blocking agents, new synthetic retinoids, and new drug delivery systems of retinoids, providing new methods for the successful clinical application of retinoids in the treatment of OLK.