Immunohistochemical Expression of p16 Lesions of the Cervix: A Cross-sectional Study

Abstract

Introduction: Cervical cancer is the second most malignant cancer that affects women globally. The most common cause for cervical cancer is persistent infection of high risk Human Papillomavirus (HPV) subtypes 16,18. Over-expression of p16 may serve as a surrogate biomarker to confirm HPV infection. Aim: The present study aimed to study high risk HPV in cervical biopsies using p16 immunostaining for detecting high grade lesions. Material and method: This cross-sectional study was conducted in the Department of Pathology, Sree Mookambika Institute of Medical Sciences, Tamil Nadu from January 2019 to February 2021 involving all women with cervical biopsies and excluding HPV vaccinated women. Samples were collected in 10% formalin. Specimens were processed and paraffin embedded. The section were stained with Haematoxylin and Eosin (H&E) and immunohistochemical staining p16 and analysed using Statistical Package for the Social Sciences (SPSS) software trial version 20.0 by qualitative analysis test i.e Chi-square test. Results: The study included 53 cases. Age distribution was between 32-78 years, with majority in 4th to 5th decades. In the study 26 (49.1%) cases were non neoplastic lesions, 16 (30.19%) were premaliganant lesions and the remaining 11 (20.75%) were malignant lesions. The difference in the proportion of HPV diagnosis between age group was statistically significant (p-value 0.003). All the non-neoplastic lesions of cervix showed negative p16 staining. Out of 16 (30.19%)premalignant lesions, 15 (93.75%) had Low grade Squamous Intraepithelial Lesion (LSIL) and only 1 (6.25%) had High grade Squamous Intraepithelial Lesion (HSIL). Few low grade lesions 7 (100%) had negative staining and all the cervical carcinoma patients showed p16 positivity. Conclusions: p16 expression was progressively increased with increasing grades of cervical neoplasm. So p16 may be useful as an adjunct in histological sections to detect HPV in those lesions which can help us to predict the progression of disease

Keywords

• cervical lesions
• immunostaining
• squamous cell carcinoma
• squamous intraepithelial lesion