Survivin and cortactin expression in sinonasal schneiderian (inverted) papilloma and associated carcinoma

Sinonasal inverted (schneiderian) papilloma (IP) is histologically benign but shows a propensity for malignant transformation. Survivin, a member of the inhibitor of the apoptosis family of proteins that controls cell division, apoptosis, metastasis, and, probably, also neoangiogenesis, is overexpressed in essentially all human cancers. Overexpression of the multidomain protein cortactin has also been associated with increased cell migration, invasion, and metastatic potential in several malignancies. The aim of the present study was to preliminarily investigate survivin and cortactin expression in a consecutive series of sinonasal IPs, and IP-associated squamous cell carcinomas (SCC). Immunohistochemical expression of nuclear survivin and cortactin was measured in 19 consecutive sinonasal IPs and 3 IP-associated SCCs. The mean ± standard deviation nuclear survivin expression was 9.4 ± 9.2% and 31.7% ± 15.4% in sinonasal IPs and SCCs, respectively (p < 0.0001). Results of cortactin immunostaining was strongly positive in the cytoplasm of both sinonasal IPs and SCCs: no significant difference emerged between the IP and SCC epithelial components. Nuclear survivin expression was significantly higher in SCCs than in IPs. Prospective, multi-institutional prognostic studies, preferably on an international scale (given the few cases treated at single institutions), are needed to confirm the role of survivin in IP malignant transformation