Validation of a new classification system For categorizing oral epithelial dysplasia

Abstract

Introduction: The mortality of oral cancer has increased seven times in the last 50 years in-spite of millions worth research going on globally. India has one of the highest rates in oral cancer in the world partly attributed to high prevalence of tobacco chewing. Alarmingly 194 million people aged 15 years and older have tobacco habit. In parallel to the increase in Oral Cancer, border-line malignant lesions which range from epithelial dysplasia to intra epithelial carcinoma have also increased in numbers. These lesions are significant part of routine oral pathology service. Not all precancerous lesions and conditions transform to cancer. Morphological alterations amongst some may have an increased potential for malignant transformation. The current histopathological grading of oral dysplasia lesions is notably unreliable mainly due to lack of objective and validated grading features. Many studies have shown wide variability in the diagnosis and grading of oral epithelial dysplasia (OED) with results demonstrating only poor to moderate agreement. The customary grading system of oral epithelial dysplasia into mild, moderate and severe does not allow accurate prediction of which cases may eventually transform into malignancy. Many studies have remarked that precancers with epithelial dysplasia have shown to develop into cancer more readily than lesions without. Nevertheless all precancer or epithelial dysplasia do not develop into cancer, whereas, some have even shown to regress with time. Objectives: The present study was undertaken to assess the different grading systems to determine the inter observer and intra observer variation and to study the individual features defining atypia and general disturbance in the epithelium of oral epithelial lesions; dysplasia. An attempt is also made to correlate the histopathological features with Immunohistochemistry markers for cytokeratin (CK-19), basement membrane enhancement protein (Ki-67) and extracellular matrix change (MMP-9) so as to substantiate the observation o