Ki-67 Prognostic Value in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Document Type : Research Articles


1 Department of Oral Histology and Pathology, University of Damascus,Damascus, Syria.

2 Department of Periodontology, University of Damascus,Damascus, Syria.

3 DESS Dental Public Health, Lebanese University, Beirut , Lebanon.

4 Department of Endodontics and Operative Dentistry, Faculty of Dentistry, University of Damascus, Damascus, Syria.


Introduction: Abnormal cell proliferation appears to be a possible predictor of tumorigenesis, Ki-67 protein
expression is closely related to the cell proliferation and could be used as a biomarker for the growth in the most of
human tumors. The aim of the study: Investigating of Ki-67 expression in the pathological grades of oral epithelial
dysplasia and oral squamous cell carcinomas. Materials and Methods: The sample consisted of 30 formalin-fixed,
paraffin-embedded specimens of oral epithelial dysplasia (OED), 30 other of oral squamous cell carcinomas (OSCC), and
10 normal oral epithelium (NOE) were conventionally stained with hematoxylin and eosin and immunohistochemically
stained with Ki-67 monoclonal antibody. Results: Expression of Ki-67 was restricted to the basal layers in the normal
oral epithelium whereas Ki-67 positive cells in oral epithelial dysplasia (OED) were located in the basal, suprabasal
and spinous layers, Ki-67 expression was increased in high-risk cases. Ki-67 positive cells in well-differentiated
(OSCC) were located mainly in the periphery of the tumor nests, in moderately-differentiated (OSCC) were located
in both peripheral and part of a center of the tumor nests whereas it was diffused in most of the Poorly-differentiated
(OSCC). Statistical analysis indicated a significant difference between the expression in (OED) and (NOE), (OSCC)
and (NOE), and no differences between (OED) and (OSCC). Conclusion: This study has concluded that Ki-67 antigen
could be used as a marker for the histological grading of OED and OSCC, Expression of Ki 67 increased according to
the severity of oral epithelial dysplasia.




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