Inverting Papilloma (IP) is a rare neoplasm of the nose and paranasal sinuses. It is considered to be a premalignant lesion as there is a 7–21% incidence of squamous cell carcinoma (SCC) associated with IP. Although there have been many attempts to assign prognostic significance to various features of IP, there has not been a single reliable prognostic indicator identified. Recently it has been shown that mutations of the p53 tumor suppressor gene (TSG) are commonly involved in the process of cancer development. It has been assumed that cells which stain positive with p53 monoclonal antibody (MAb) contain mutant protein due to its lengthened half-life. To better understand the relationship of IP and carcinoma, we analyzed tumor specimens from 12 patients for p53 gene alterations using immunohistochemistry and DNA sequencing. Seven patients had IP without dysplasia, and five patients had IP with dysplasia or squamous cell carcinoma (SCC). All seven patients with IP only had tumors negative for p53 TSG. Three of five patients with IP and dysplasia or SCC stained positive for p53 TSG. No gene alterations of p53 TSG were detected in this study. The role and significance of p53 TSG in the tumorigenesis of IP is discussed based on these findings.
Analysis of Expression of p53 Tumor Suppressor Gene in Human Oral Squamous Cell Carcinoma.
