p21, p53, and p27 Kip1 alterations in benign and malignant tumors of sinonasal epithelium.

Objective: The goal of this study was to investigate alterations of cell cycle-related molecules, including p27, p21, and p53, in inverted papillomas (IPs) and squamous cell carcinomas (SCCs) of the sinonasal epithelium. Study design Sixteen IPs and 6 SCCs of the sinonasal epithelium, surgically resected at Istanbul Faculty of Medicine, Department of Otorhinolaryngology, from 1992 to 2000 were immunohistochemically investigated (p27, p21, and p53).

Results: A significant decrease in p27 nuclear staining was observed for SCCs of paranasal sinus compared with inverted papillomas (P = 0.0072). In SCCs there was no association between p27 expression and the presence of keratinization and tumor grade. p21 and p53 expressions were not associated with IPs (dysplastic and nondysplastic) and SCCs.

Conclusion: Reduced levels of p27 expression correlate with increased cell proliferation in tumors of sinonasal region. Our findings indicate that p27 immunohistochemistry can be recommended to analyze the dysregulation of cell kinetics in these tumors.