Expression of proliferative marker Ki-67 in epithelial dysplasia and squamous cell carcinoma of oral cavity

Abstract

Background: The proliferative index helps to evaluate the growth rate and aggressiveness of the malignant tumor. Ki-67 is one of the proliferating markers that help to predict the patient's survival in Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC). Hence, the present study evaluated the expression of Ki-67 in OSCC and OED. Aim and Objectives: To evaluate the expression of Ki-67 in OED and OSCC and to correlate the Ki-67 expression with various grades of OED and OSCC. Material and Methods: A prospective observational study was done on clinically suspected oral epithelial dysplasia and malignancy cases received in the histopathology section. For each case, two sections of 4 μm were prepared. One was stained by hematoxylin and eosin stain, and another section was used for immunohistochemical staining of Ki-67. Results: Out of 64 cases evaluated for Ki-67 expression, 19 cases were OED, and 45 were OSCC. In OED, 15 cases were mild, and three were severe. In severe OED, Ki-67 expression was seen in all three lining epithelium layers: basal, parabasal, and spinous. In mild OED, Ki-67 expression was noted only in the basal layer. Out of 45 cases of OSCC, 31 cases were moderately differentiated, and one was poorly differentiated OSCC. Ki-67 expression was highest in poorly differentiated OSCC and lowest in well-differentiated OSCC. Conclusion: Ki-67 expression was high in poorly differentiated carcinoma compared to well-differentiated squamous cell carcinoma, and in severe OED Ki-67 was noted in all layers of lining epithelium. These findings suggest that Ki-67 expression correlates with the grading of OED and OSCC. Thus, it can be considered a proliferating marker that predicts the malignant transformation in OED and the aggressiveness of tumor.

Keywords

• epithelial dysplasia
• ki-67
• squamous cell carcinoma