Immunohistochemistry analysis of P16INK4a in pre-invasive ocular surface squamous neoplasia tissue samples infected and not infected by human papilloma virus at an academic laboratory in Northern Tshwane.

Ocular surface squamous neoplasia (OSSN) encompasses a wide range of benign and malignant tumours that arise from the conjunctiva and cornea. Tumour progression involves various genetic and epigenetic changes affecting oncogenes. The tumour suppressor gene P16INK4a serves as a key biomarker for high-risk humanpailloma virus (HR-HPV) infection in squamous neoplasms. This study assessed the prognostic significance of P16INK4a in pre-invasive ocular surface squamous neoplasia tissue samples. This retrospective study analysed 58 formalin fixed paraffin embedded (FFPE) tissue samples of OSSN with known HPV results for the expression of P16INK4a immunohistochemistry marker at an academic laboratory in Tshwane. Data was analysed using STATA v16.1 software, and descriptive and inferential statistics were used to summarise the study findings. The study analysed OSSN samples of 35 females (60.34%) and 23 males (39.66%), with a mean age of 41.8 years. The overall prevalence of P16INK4a among the study samples was 22.4% (13/58). In HPV-positive samples, the prevalence of P16INK4a was 76.9% (10/13). The P16INK4a was detected in both high-risk (HR) and low-risk (LR) HPV positive conjunctival intraepithelial neoplasia (CIN) grade III cases. There was a statistically significant association between P16INK4a and HPV genotypes, with p-values of 0.033 and 0.045 for both linear array (LA) and real time polymerase chain reaction (RT-PCR) techniques, respectively. A lower prevalence of P16INK4a was observed in HPV-negative OSSN samples and a fair prevalence of P16INK4a was noted in HPV-positive OSSN samples with combined HPV detection techniques. The relationship between P16INK4a with prognosis and HPV infection in OSSN remains inconclusive.