Invasion and the depth of invasion affect significantly the prognosis in urothelial carcinomas. The histopathologic evaluation of invasion may be problematic in some cases. Application of new immunohistochemical markers may facilitate the assessment of invasion. Fascin, one of these markers, is an actin-bundling protein involved in tumor cell migration. Fascin expression is increased in various carcinomas. Prior to this research, to our knowledge, only one study exists regarding fascin expression in urothelial carcinomas.
To characterize the expression of fascin in additional cases of urothelial carcinoma and to verify statistically a relationship between fascin overexpression and invasiveness in these tumors.
We examined fascin immunoreactivity in 116 specimens of urothelial carcinomas obtained from 116 patients including 96 men and 20 women. Fifty-eight cases were ranked as low-grade carcinomas, pTa stage, and 58 cases were ranked as high-grade carcinomas--11 were ranked as stage pTa, 21 were ranked as pT1, and 26 were ranked as pT2 carcinomas. Fascin immunoreactivity was assessed semiquantitatively in tumor cells. In each case, we ascribed 3 immunoreactivity scores, one for extent, one for intensity, and a combined immunoreactivity score.
The combined immunoreactivity score was significantly higher in invasive carcinomas. In addition, strong staining was observed exclusively in invasive carcinomas. None of the pTa tumors demonstrated intense staining, including those ranked at the higher grade.
Our results point to an association between fascin immunostaining and urothelial carcinoma invasiveness and suggest that fascin overexpression may be a marker of aggressive urothelial carcinomas.