Oral premalignant lesions: from a clinical perspective

Abstract

In this review article, the clinical and histopathological characteristics of oral premalignant lesions, and primarily oral leukoplakia, are noted and the risk factors for malignant transformation of oral leukoplakia are discussed. Malignant transformation rates of oral leukoplakia range from 0.13 to 17.5%. The risk factors of malignant transformation in the buccal mucosa and labial commissure are male gender with chewing tobacco or smoking in some countries such as India, or older age and/or being a non-smoking female in other countries. Some authors have reported that leukoplakia on the tongue or the floor of the mouth showed a high risk of malignant transformation, although others have found no oral subsites at high risk. In concurrence with some authors, the authors of this review view epithelial dysplasia as an important risk factor in malignant transformation; however, there are conflicting reports in the literature. Many authors believe that nonhomogeneous leukoplakia is a high risk factor without exception, although different terms have been used to describe those conditions. The large size of lesions and widespread leukoplakia are also reported risk factors. According to some studies, surgical treatment decreased the rate of malignant transformation; however, many review articles state that no definitive treatment including surgery can decrease the malignant transformation rate of oral leukoplakia because of the lack of randomized control trials of treatment. Tobacco chewing and smoking may be causative agents for cancerization of oral leukoplakia in some groups, and evidence for a role of human papilloma virus in the malignant transformation of oral leukoplakia is inconsistent. Further research to clarify its role in malignant transformation is warranted.

Expression of E-cadherin and involucrin in leukoplakia and oral cancer: an immunocytochemical and immunohistochemical study

“…13 In addition, individuals in the leukoplakia group had a higher consumption of tobacco than of alcohol, so we consider tobacco to be the main etiologic factor of leukoplakias in our sample, as previously described by other authors. 13,14 Most individuals presented poor oral hygiene in both groups. The most common sites of lesions were the tongue and floor of the mouth, which are the locations mostly affected by oral squamous cell carcinoma.…”

Loss of DLC1 is an independent prognostic factor in patients with oral squamous cell carcinoma

“…However, screening for head and neck cancer in premalignant stages and identifying oral premalignant lesions (dysplasia) at high risk of transformation is currently unpredictable. [5][6][7][8]41,42 Furthermore, the histological diagnosis of dysplasia can be subjective and is thus prone to considerable variations in interpretations among pathologists. Thus, molecular biomarkers capable of identifying the subset of lesions likely to progress to cancer are required to eliminate this clinical diagnostic dilemma.…”

An Update on Precancerous Lesions of Oral Cavity

“…The accelerated pace of cell division noted at the earlier stages of transformation as a part of adaptive response (to replace the damaged cell pool) is, in a way, facilitative of the accumulation of further genetic damage, thereby driving the cells further along the path of transformation. [13,14] Clinical classification: [15]  o Phase IV: Erythroleukoplakia -poor prognosis. [10] The current "gold standard" for predicting the malignant potential of premalignant lesions is the presence and degree of dysplasia.…”