A quantitative expression of Ki-67 to evaluate malignant transformation rate in potentially malignant disorders

Objective: To evaluate the quantitative expression of Ki-67 in oral leukoplakia, oral submucous fibrosis (OSF) and to compare their expression with normal oral epithelium. Materials and Methods: Thirty archival paraffin-embedded blocks were retrieved from the Department of Oral and Maxillofacial Pathology. It includes three groups with 10 specimens each of histopathologically confirmed oral leukoplakia, OSF, and controls, which were taken as standard for comparison. Ki-67 immunostaining was detected and numbers of positive cells out of 1000 were counted in 10 random high-power fields in each case. Statistical analysis was done using one-way analysis of variance test. Results: Mean and standard deviation of oral leukoplakia was found to be higher (398 ± 82) followed by OSF (343 ± 83) and controls (290 ± 72). Pairwise comparison of three groups with respect to expression of total number and percentage of cells was statistically significant between oral leukoplakia and controls (P < 0.05). Conclusion: The results of the present study emphasize that malignant transformation rate was higher for oral leukoplakia compared with OSF and controls. Hence, it serves as a prognostic tool for early detection of malignancy.