West Asia Organization for Cancer Prevention (WAOCP), APOCP's West Asia Chapter. Asian Pacific Journal of Cancer Prevention 1513-7368 19 11 2018 11 01 Ki-67 Prognostic Value in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma 3279 3286 76651 10.31557/APJCP.2018.19.11.3279 EN Amer Takkem Department of Oral Histology and Pathology, University of Damascus,Damascus, Syria. Charif Barakat Department of Oral Histology and Pathology, University of Damascus,Damascus, Syria. Safa Zakarea Department of Oral Histology and Pathology, University of Damascus,Damascus, Syria. Khaled Zaid Department of Oral Histology and Pathology, University of Damascus,Damascus, Syria. 0000-0003-1034-4061 Johnny Najmeh Department of Periodontology, University of Damascus,Damascus, Syria. Mahdi Ayoub DESS Dental Public Health, Lebanese University, Beirut , Lebanon. Mohammad Yaman Seirawan Department of Endodontics and Operative Dentistry, Faculty of Dentistry, University of Damascus, Damascus, Syria. Journal Article 2018 06 30 Introduction: Abnormal cell proliferation appears to be a possible predictor of tumorigenesis, Ki-67 protein<br />expression is closely related to the cell proliferation and could be used as a biomarker for the growth in the most of<br />human tumors. The aim of the study: Investigating of Ki-67 expression in the pathological grades of oral epithelial<br />dysplasia and oral squamous cell carcinomas. Materials and Methods: The sample consisted of 30 formalin-fixed,<br />paraffin-embedded specimens of oral epithelial dysplasia (OED), 30 other of oral squamous cell carcinomas (OSCC), and<br />10 normal oral epithelium (NOE) were conventionally stained with hematoxylin and eosin and immunohistochemically<br />stained with Ki-67 monoclonal antibody. Results: Expression of Ki-67 was restricted to the basal layers in the normal<br />oral epithelium whereas Ki-67 positive cells in oral epithelial dysplasia (OED) were located in the basal, suprabasal<br />and spinous layers, Ki-67 expression was increased in high-risk cases. Ki-67 positive cells in well-differentiated<br />(OSCC) were located mainly in the periphery of the tumor nests, in moderately-differentiated (OSCC) were located<br />in both peripheral and part of a center of the tumor nests whereas it was diffused in most of the Poorly-differentiated<br />(OSCC). Statistical analysis indicated a significant difference between the expression in (OED) and (NOE), (OSCC)<br />and (NOE), and no differences between (OED) and (OSCC). Conclusion: This study has concluded that Ki-67 antigen<br />could be used as a marker for the histological grading of OED and OSCC, Expression of Ki 67 increased according to<br />the severity of oral epithelial dysplasia. https://journal.waocp.org/article_76651_e8d8bdfc8310aec6b7703fabf17d7444.pdf