Immunohistochemical expression of secreted frizzled receptor protein 1 in the invasive front of tongue squamous cell carcinoma.

The Wnt signalling pathway is involved in the development of oral cancer. When inactivated, secreted frizzled receptor protein 1 (SFRP1), a cellular Wnt-inhibitor protein, may enhance cancer development. The aim of this study was to assess the expression of SFRP1 in the invasive front of tongue squamous cell carcinoma (SCC). Immunohistochemical expression of SFRP1 in the cohesive and discohesive invasive front of 36 resection specimens of tongue SCC was investigated. Immunostaining was compared with tumour size, tumour thickness, and neural invasion. Immunoreactivity increased in depth from the surface of the tumour to the invasive front. There was a statistically significant association between type of invasive front and pattern of SFRP1 expression. A discohesive invasive front showed more intense immunoreactivity. No statistically significant associations were found between the intensity of staining and relevant prognostic factors. Tongue SSC has variable SFRP1 expression in different parts of the tumour and the greatest expression is in the invasive front. The more intense staining in the discohesive invasive front compared with the cohesive invasive front might contribute to the worse prognosis of cancers with a discohesive invasive front.