Value of p16 Expression in the Detection of High-Grade Squamous Intraepithelial Lesion of Cervix

Abstract

Background: Cervical intraepithelial neoplasia (CIN) is usually a precancerous condition but, if left untreated, can develop into invasive cervical cancer. CIN2 and CIN3 are combinedly termed high-grade squamous intraepithelial lesions (HSIL). There are few screening tests based on cytology in detecting HSIL, but they are mostly less accurate. There is over-expression of p16 in pre-cancer and cancer of the cervix. The purpose of this study was to determine the value of p16 expression in the detection of HSIL. Methods: It was a cross-sectional study conducted in the colposcopy clinic of the Department of Obstetrics and Gynecology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from October 2021 to March 2022. The study included 72 HSIL patients detected by colposcopy and had subsequent cervical biopsy and p16 immunohistochemistry. Results: Majority (45.8%) of the patients were found within the 30-39 years age group, 44.4% of the participants were illiterate, and 76.4% came from the middle-income group. Colposcopy-directed cervical Punch or Loop electrosurgical excision procedure (LEEP) biopsy revealed that 70.5% of patients had HSIL, and the rest (64.3%) suffered from LSIL. Positive p16 results were significantly higher among the HSIL group (84.1%) compared to those other than the HSIL group (3.6%) (p<0.001). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the p16 in the detection of HSIL were 84.1%, 96.4%, 79.4%, and 88.9%, respectively. Conclusions: Immunohistochemistry for p16 has a high diagnostic value in detecting HSIL patients. Therefore, this could be recommended for appropriate management of patients with CIN to avoid misdiagnosis and the over or under-treatment.