Prognostic value of E-cadherin expression in thyroid follicular carcinoma

Aims To evaluate the expression of E-cadherin, its association with various clinicopathological features and its possible relation with distant metastasis-free survival (DMFS) in follicular carcinoma of the thyroid. Methods E-cadherin expression was assessed immunohistochemically in sections from paraffin embedded tissues in a group of 54 patients with follicular carcinoma and its variants who were followed for a median of 7.25 years. Results Reduced E-cadherin expression, defined as <90% of cells showing membrane positivity, was found in 15 tumours and was significantly associated with widely invasive growth, insular morphology and lesser degree of differentiation, but was not related to patient sex and age or tumour size. In univariate analysis, DMFS was significantly worse in male patients (P<0.03), widely invasive tumours (P=0.0002), moderately/poorly differentiated tumours (P<0.05) and tumours showing reduced E-cadherin expression (P=0.0001). In multivariate analysis, the degree of invasiveness and E-cadherin expression were the only independent prognostic factors. Among widely invasive cases, those with reduced E-cadherin expression had significantly worse DMFS than those with preserved expression. Conclusions Our findings suggest that E-cadherin expression could be used as a prognostic marker in widely invasive follicular carcinomas of the thyroid. Larger studies are needed to assess its prognostic value in the group of minimally invasive carcinomas.