MATERIALS AND METHODS: Total of 50 samples were selected for the study and were categorized into five groups and 10 samples in each group as Group I-oral leukoplakia (OL), Group II-oral lichen planus (OLP), Group III-oral submucous fibrosis (OSMF), Group IV-oral squamous cell carcinoma (OSCC) and Group V-normal oral mucosa (NOM) as control group. All the samples were assessed for the expression of E-cad by immunohistochemical study.
RESULTS: Upon assessing the expression of E-cad in OL, OSMF, OLP and OSCC, as majority of the samples with OSCC (90%), OL (80%), OLP (70%) and OSMF (60%) showed mild to moderate expression of E-cad staining, which was suggestive of reduction in dysplastic cells on comparison to NOM cells. This difference in expression and variation of E-cad upon comparison with normal mucosa was statistically significant (P < 0.001).
CONCLUSION: There is significant (P < 0.001) variation of expression of E-cad with the histopathological dysplasia of the oral precancerous lesions and conditions, and the tumor differentiation of the oral cancers. However, there was no correlation of the degree of loss of expression of E-cad with the degree of dysplasia or the tumor differentiation of oral cancers. We conclude with our study that, there is a variation in the expression of E-cad but its value as a prognostic marker is questionable.
DESIGN: This was a population-based, cross-sectional study whereby subjects were adults aged 18 years old and above. A workshop on the identification of OML was held to train and calibrate dental officers prior to data collection in the field. Sociodemographic and risk habits data were collected via face-to-face interview, whilst presence of OML and clinical details of lesions such as type and site were collected following clinical oral examination by the examiners. Data analysis was carried out using the Statistical Package for Social Science (SPSS) version 12.0. The association between risk habits and risk of OPMD was explored using logistic regression analysis.
RESULTS: A total of 1634 subjects were recruited. Prevalence of OML for this population was 54.1%. Linea alba was the most common lesion seen (28.7%). This study showed an overall OPMD prevalence of 5.6%. The most common type of OPMD was leukoplakia (64.8%), followed by lichen planus (30.8%). Subjects who only smoked were found to have an increased risk for OPMD of almost four-fold (RR 3.74, 95%CI 1.89-7.41). The highest risk was found for betel quid chewers, where the increased risk observed was more than six times (RR 6.75, 95%CI 3.32-13.72). Alcohol consumption on its own did not seem to confer an increased risk for OPMD, however when practiced concurrently with smoking, a significant risk of more than five times was noted (RR 5.69 95%CI 3.14-10.29).
CONCLUSION: The prevalence of OML was 54.1%, with linea alba being the most commonly occurring lesion. Smoking, alcohol consumption and betel quid chewing were found to be associated with the prevalence of OPMD, which was 5.6%.