Expression of Ki 67 in Malignant and Premalignant Cervical Lesions in Nigerian Women

Abstract

Background: Cervical cancer, though preceded by treatable premalignant lesions, ranks second among all cancers in Nigerian women. The proliferative marker ‘Ki-67’ is useful immunohistochemically to enhance the diagnosis of cervical dysplastic lesions, reducing inter-and intra-observer variability. This study is aimed at evaluating the role of Ki-67 expression in cervical dysplastic lesions as a diagnostic and prognostic tool.
Methodology: We applied Ki-67 immunohistochemical staining on 142 cervical biopsies from the archives of Nnamdi Azikiwe University Teaching Hospital (NAUTH) Nnewi in Anambra state, a federal teaching hospital. Ki-67stains nuclei of proliferating cells, and was expressed as Ki-67 scores and labeling index (LI). LI was calculated as the number of positive cells per 100 dysplastic cervical epithelial cells while Ki-67 score was given based on levels of positive staining per third of epithelial thickness. The data analysis was done using the IBM SPSS Statistics (Statistical Product and Service Solutions) software version 20.0, and the result presented with tables where relevant.
Results: LI and Ki-67 score increased with increasing dysplasia. There was disagreement between IHC (immunohistochemistry) enhanced and morphologic diagnosis in 9 (6.33%) cases. Ki-67 IHC significantly enhanced the diagnosis of CIN (Cervical intraepithelial neoplasm) and carcinomas (x2 =0.001, P<0.05). Both premalignant and malignant cervical lesions were more common in fifth and sixth decades.
Conclusion: Ki-67 IHC is a veritable diagnostic and prognostic marker, reducing inter-and intra-observer variability in the diagnosis of cervical dysplastic lesions.