VALUE OF IMMUNOHISTOCHEMICAL EXPRESSION OF P16INK4A IN VARIOUS FORMS OF CERVICAL NEOPLASIA

Abstract

Cervical cancer is the second most commonly diagnosed type of cancer and the third leading cause of cancer-associated mortality in women. P16INK4A is recognized as a tumor suppressor gene that is inactivated in many types of human cancers. However, p16 overexpression due to functional inactivation of Rb by human papillomavirus (HPV) E7 protein has been demonstrated in cervical cancers. The objective of the present study was to compare p16ink4a expression in cervical epithelial lesions and in cervical carcinoma in order to evaluate its potential diagnostic role in differentiating these lesions and to understand the part played by this marker in cervical cancer progression. This study included 42 archival paraffin embedded specimens of cases diagnosed as cervical neoplasia (cervical intraepithelial neoplasias and cervical carcinomas). These were further classified as 7 cases of low grade squamous intraepithelial lesions 'LGSIL', 4 cases of high grade squamous intraepithelial lesions 'HGSIL', 17 cases of invasive cervical squamous cell carcinoma 'ICSC', 5 invasive endocervical carcinoma 'IECC and 9 cases of endometrial carcinoma reaching to the cervix 'ECRC'. Specimens were retrieved from the Pathology laboratory of Early Cancer Detection Unit at Ain-Shams University Maternity Hospital during the period from 2010 to 2013. Five µm thick sections were cut from each block and submitted for routine Hematoxylin and Eosin staining, then examined under light microscope for histopathological revision and reassessment.