Clinicopathological Correlation and P16 Expressions in Ocular Surface Squamous Neoplasia

Abstract Introduction: Ocular Surface Squamous Neoplasia (OSSN) is defined as the range of disease from mild dysplasia to carcinoma in situ and invasive squamous cell carcinoma. OSSN may be located on cornea, conjunctiva and limbus but is mostly found on interpalpebral fissure. OSSN's regional occurrence varies. Previous epidemiological research found that the incidence of OSSN was 0.13 per lakh in Uganda and less than 0.20 per million each year in the UK. Human papillomavirus (HPV), UV exposure, and immunosuppression all have a significant impact on OSSN incidence. Human papillomavirus (HPV), UV exposure, and immunosuppression all have a significant impact on OSSN incidence. HPV contributes to cancer pathogenesis by the formation of a protein complex between the host, p53 and HPVE6 protein, resulting in the blockage of p53 supression action. The neutralization of cellular retinoblastoma tumor suppressor (pRB) and the p53 tumor suppressor protein by the HPVE6 and E7 oncogenes induces the expression of p16. Hence p16 expression is considered a marker of high risk HPV serotypes Objectives · Clinico pathological correlation in OSSN. · To evaluate the frequency and pattern of expression of p16 by immunohistochemistry in histopathologically diagnosed samples of OSSN. Methods: 35 cases of OSSN received in Bangalore Medical College and Research Institute were studied. After routine processing, Hematoxylin and eosin staining and p16 immunohistochemistry was performed. Results: 35 cases of OSSN cases were studied using H&E for histologic type, grade and stage. Immunohistochemical analysis was done to evaluate p16 expression and its correlation with grade of the tumor were studied. In our present study 27 out of 35 cases showed p16 positivity, suggesting that there is significant association between HPV and OSSN. In our study no statical significance was found between p16 positivity and different grades of OSSN Conclusion: 77% of the cases showed positive p16 staining, suggesting that there is a strong correlation between HPV and OSSN in the cases under investigation. P16 came positive more in higher grades such as grade III OSSN and SCC but no statically significant association was found between different grades of OSSN and p16 expression. However, this creates opportunities for more extensive research on p16 in OSSN in the future with more sample size, which could aid in determining a standard cut-off point for OSSN grading.