The Role of Immunohistochemical P16 Tissue Expression in Determining the Presence of the Main Oncoproteins E6 and E7 of Human Papilloma Virus: A Systematic Review

Objective This systematic review was planned to examine the predictive effect of tissue expression of p16, a cycle inhibitor, in predicting the presence of E6 and E7 proteins, which are the main oncogenes that play a role in the cancer development of Human Papilloma Virus (HPV) and are found only in high-risk HPV types.

Materials and Methods The 1570 articles that made up the study's population were found by searching the "Pubmed," "Medline," "Dergipark," "Elsevier," "Google Scholar," and "Networked Digital Library of Theses and Dissestations" databases between January and March 2024. In the review, articles published in the last 20 years with the keywords "carcinogenesis", "Human papilloma virus", "E6", "E7" and "p16 tissue expression", published in Turkish or English and with full text were selected. The study's sample consisted of 20 papers in total that satisfied the research requirements from these publications.

Results The main oncogenes of HPV, E6 and E7, which are thought to be effective in the development of carcinogenesis, were found to be mostly positive in anogenital cancers. In most systems, p16 tissue expression correlated with HPV positivity (P=0,001, r=0,723).

Conclusions The reviewed literature indicates that there is a strong correlation between cervical squamous cell lesions and high-risk HPV. Particularly in urogenital cancers, p16 tissue expression is also associated with HPV positivity and prognosis. Thus, it was determined that routine use of immunohistochemical examination to investigate the presence of p16 is both required and beneficial. However, considering that the correlation between p16 expression and HPV infection is quite low in head and neck cancers, except for the oropharynx, molecular tests should also be performed to detect HPV infection in HNSCCs.