Role of Ki67 Protein in Pap Stained Cervical Cytology Smear in Differentiating Dysplastic Lesions from Benign Lesions of the Cervix

Purpose: The PAP smear has significantly reduce the mortality and morbidity of cancer cervix however there is some debates of it as interobserver variability and high false negative and false-positive rates so parameters of cell proliferation have emergedas important diagnostic and prognostic tools. Aim of the Work: This present study aimedtoevaluate the efficiency of Ki67 in differentiating dysplastic lesion from benign lesion of cervical cytology smear. Patients and Methods: This cross-sectional study included 67 cases of cervicovaginal cytology smear of all gynecological cases in Benha University Hospital and Early Cancer Detection Unit, Pathology Department, Benha Faculty of Medicine during the period of October 2014-May 2015. Immunocytochemical Ki67 expression was both graded as well as Labelling Index was calculated. Statistical evaluation was carried out using the Fisher’s Extract test, Student t-test (p<0.05), Mann Whitney U test and Rho test, ROC curve, sensitivity, specificity and accuracy was calculated by using area under the curve. Results: There was increase in mean Labelling Index of Ki67 immunocytochemical staining with increasing grade of dysplasia as the p-value among these groups was highly statistically significant (p-value <0.001). Labelling index was maximum in HSIL and minimum in benign lesions. Conclusion: Ki-67 immunocytochemistry may be of value as a complementary tool in PAP stained cervical cytology and reducing the need of tissue biopsy as it is simple, reliable and easily applicable in routine cytosmears. Ki67 biomarker can be used in the evaluation of the proliferative activity and progressive potential of dysplastic and neoplastic changes.