Year: 2026 | Month: September | Volume: 16 | Issue: 9 | Pages: 167-174
DOI: https://doi.org/10.52403/ijhsr.20260919
A Study to Evaluate the Immunohistochemistry Expression of Ki-67 in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma
Karitika Aggarwal1, Mohanvir Kaur2, Ninder Kumar3, Kanwardeep Kaur4, Anubha Garg5
1Junior Resident, 2,3,4,5Associate Professor,
1,2,3,4Department of Pathology, 5Department of Surgical Oncology,
Government Medical College & Rajindra Hospital, Patiala, Punjab, India
Corresponding Author: Dr. Kanwardeep Kaur
ABSTRACT
Background: Oral squamous cell carcinoma (OSCC) constitutes nearly 90% of oral malignancies and frequently arises through oral epithelial dysplasia (OED), a part of the spectrum of oral potentially malignant disorders. Ki-67, a nuclear proliferation-associated antigen expressed during the active phases of the cell cycle, reflects the proliferative activity of epithelial cells and has been proposed as a marker for grading severity of OED and OSCC.
Aims and Objectives: To study the histopathological features of oral neoplastic lesions and to score Ki-67 immunoexpression across different histological grades of OED and OSCC.
Materials and Methods: This prospective study was conducted over 1.5 years in the Department of Pathology, Government Medical College, Patiala. 80 cases of OED and OSCC fulfilling the inclusion criteria were studied. Haematoxylin and eosin-stained sections were used for histopathological diagnosis and grading, and immunohistochemistry with Ki-67 monoclonal antibody was performed on all cases. The Ki-67 labelling index (percentage of positive cells per 1000 cells counted at ×400 magnification) and a four-point expression score (0–3) were determined and correlated with histological grade, gender, anatomical site and tobacco use, using the Chi-square test, with p<0.05 considered significant.
Results: Of 80 cases, 14 (17.5%) were OED (5 mild, 7 moderate, 2 severe) and 66 (82.5%) were OSCC (26 well-differentiated, 34 moderately-differentiated, 6 poorly-differentiated). The mean age was 53.33±13.15 years with male predominance (75%). The mean Ki-67 labelling index increased significantly from mild to severe OED (14.60±5.90 to 25.00±1.41; p=0.017) and from well- to poorly-differentiated OSCC (24.92±4.05 to 47.17±10.72; p<0.001). The Ki-67 expression score showed a highly significant association with histopathological diagnosis (χ²=19.217, p<0.001), and tobacco use was strongly associated with OSCC (χ²=12.214, p<0.001).
Conclusion: Ki-67 expression increases progressively with increasing severity of OED and decreasing differentiation of OSCC. It can therefore serve as a useful adjunct biomarker for grading oral epithelial lesions, assessing their biological behaviour and identifying lesions at higher risk of malignant transformation.
Key words: Ki-67; Oral epithelial dysplasia; Oral squamous cell carcinoma; Immunohistochemistry; Labelling index; Proliferation marker.