Premalignant lesions of the oral cavity: a narrative review of factors and mechanisms of transformation into cancer

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer. The development and progression of OSCC are closely linked to various aetiological factors. Early signs of OSCC may manifest as oral lesions, genetic abnormalities, and chronic inflammation. Lesions with dysplastic features have a high risk of malignant transformation into OSCC. Moreover, dysplastic lesions are characteristic of many oral potentially malignant disorders (OPMDs). Currently, there is no unified standard of treatment for OPMD patients, due to the variability in risk factors and mechanisms of transformation. Therefore, it is essential to detect and manage OPMDs at an early stage in order to prevent their malignant transformation into OSCC. This necessitates analysing OPMD mechanisms to identify objective markers for predicting the risk of malignant transformation. The aim of this review was to describe the process of OPMD transformation into OSCC under the influence of environmental, immune, microbiome, and molecular factors.