Ki-67 Expression in Oral Potential Malignant and Malignant Lesions and Correlation of Mitotic Index with MIB-1 Labeling Index

Abstract

Introduction: Oral cancers are the most serious health issues in underdeveloped countries such as India and considered as the main cause of death. Among them, oral squamous cell carcinoma is the most common type (90%) of all malignancies. Various oral potential malignant lesions (OPMLs) can transform into malignancies. This study was conducted to determine the significance of Ki-67 expression in oral potential malignant and malignant lesions (MLs) as well as correlation of mitotic index (MI) with MIB-1 labeling index (LI) in these lesions. Materials and Methods: The study was performed on 60 cases in a tertiary care center over a period of 2 years. Ki-67 expression, MI and MIB-1 LI were calculated and correlated. Results: In the studied population, there were 49 (81.7%) males and 11 (18.3%) females. The mean age was 46.60 ± 9.94 (23–68 years), with majority of patients in 41–60 years of age group (46/60 cases). Anterior 2/3rd tongue is the most affected site, presented ulcer as the most common lesion. Smoking, tobacco, and betel nutchewing addiction were presented in 72% of the patients. Among 60 cases, 45 (75%) were OPMLs, while 15 (25%) cases were MLs. MI increases in OPMLs and MLs and comparison was significant (P < 0.01). MIB-1 LI was significant (P < 0.01) on comparison to dysplasia III and MLs. A positive correlation (0.01) was established between MI and MIB-1 LI of OPMLs and MLs. Conclusion: Ki-67 expression was found correlated with the progression of disease from OPMLs to MLs. Therefore, it is considered a proliferative marker that corresponds with disease progression. Both proliferative indices (MI and MIB-1 LI) are positively correlated.