Immunohistochemical evaluation of Ki67 in predicting malignant transformation in oral submucous fibrosis

Oral submucous fibrosis (OSMF) is a potentially malignant disorder with a risk of progressing to oral squamous cell carcinoma. A key indicator of malignant transformation is increased and uncontrolled cell proliferation, which can be evaluated using markers such as Ki67. This study aimed to assess Ki67 expression in OSMF, compare its levels across different associated habits, and correlate expression with clinical and histological grading. This prospective study included 180 histopathologically confirmed cases, divided into three groups: 60 each of oral submucous fibrosis, oral squamous cell carcinoma, and normal oral mucosa. Immunohistochemistry was performed on 3 µm thick formalin-fixed, paraffin-embedded tissue sections using a monoclonal Ki67 antibody (clone MIB-1). Statistical analysis was conducted using SPSS version 21, and chi squared tests were applied, with significance set at p < 0.05. High Ki67 expression was observed in 51 of 60 Oral submucous fibrosis cases, significantly greater than in normal oral mucosa and slightly lower than in oral squamous cell carcinoma, where 57 of 60 cases showed high expression. A statistically significant correlation was found between Ki67 expression and high-risk habits, clinical stages, and histological grades (p < 0.05). The progressive rise in Ki67 expression from normal oral mucosa to oral submucous fibrosis and oral squamous cell carcinoma underscores its role as a biomarker for malignant transformation. While not a direct cause, elevated Ki67 reflects increased proliferative activity and malignancy risk. These findings highlight the utility of Ki67 in early detection, prognosis, and monitoring of oral submucous fibrosis patients to prevent malignant progression.