ASSOCIATION OF HIGH RISK HUMAN PAPILLOMA VIRUS (HPV-16/18) WITH P16 PROTEIN IN ORAL PREMALIGNANT LESIONS AND ORAL SQUAMOUS CELL CARCINOMA

Abstract

Background: Oral cancer is a major problem globally. The strong causal association with tobacco, prevalent in Pakistan makes it imperative to know the role of molecular events in oral oncogenesis. We aim to evaluate high risk HPV 16/18 and p16 in oral premalignant lesions (OPL) and oral squamous cell carcinoma (OSCC). We further analyze the association between high risk human papilloma virus (HR-HPV16/18) and p16 in OPL and OSCC. Methods: A total of 100 OSCC and 50 OPL cases were included. Demographic data along with habitual exposure to smoked and chewable tobacco, betel and gutka etc., was noted. We evaluated p16 in OPL and OSCC by immunohistochemistry, HPV was detected by polymerase chain reaction. Data was entered and analyzed using SPSS 21. Chi square and Fisher exact were applied to determine the association of HPV and p16 with different variables. Results: Out of 50 OPL, 14% were positive and 86% were negative for p16 whereas out of 100 OSCC, 18% were positive and 82% were negative. Out of 50 OPL, HPV was detected in 6% whereas out of 100 OSCC, 15% were positive. Highly significant co expression of HPV with p16 was observed in all 15 (100%) HPV positive OSCC cases (p = 0.001). However, 3 out of 18 cases, which showed p16 expression, did not show HPV infection. Conclusion: Role of p16 as a surrogate marker for HPV in OSCC can be supported in the present study. Moreover a Chemical carcinogen like tobacco is considered as major associative risk factor with p16 and HPV in concert.