THE ROLE OF THE P53 TUMOR-SUPPRESSOR GENE IN THE TUMORIGENESIS OF INVERTING PAPILLOMA OF THE NOSE AND PARANASAL SINUSES

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. Alt hough there have been many attempts to assign prognostic significance to various features of IP, there has not been a single reliable progno stic indicator identified. Recently it has been shown that mutations o f the the p53 tumor suppressor gene (TSG) are commonly involved in the process of cancer development. It has been assumed that cells which s tain positive with p53 monoclonal antibody (MAb) contain mutant protei n due to its lengthened half-life. To better understand the relationsh ip of IP and carcinoma, we analyzed tumor specimens from 12 patients f or p53 gene alterations using immunohistochemistry and DNA sequencing. Seven patients had IP without dysplasia, and five patients had IP wit h dysplasia or squamous cell carcinoma (SCC). All seven patients with IP only had tumors negative for p53 TSG. Three of five patients with I P and dysplasia or SCC stained positive for p53 TSG. No gene alteratio ns of p53 TSG were detected in this study. The role and significance o f p53 TSG in the tumorigenesis of IP is discussed based on these findi ngs.