SUMMARY
BACKGROUND: The aberrant activation of Wnt signalling pathway may be a common denominator for the development of thyroid tumorigenesis. It was announced that the loss of E-cadherin rather than ß-catenin mutation represents a crucial event in determining the degree of differentiation of thyroid carcinomas.AIM: The aim of the study was to evaluate the expression of E-cadherin and ß-catenin in the thyroid cancer tissue and to correlate these data with some histological and clinical parameters of the tumours.MATERIAL AND METHODS: We investigated 112 patients, having thyroid tumours – papillary, follicular, anaplastic and oncocytic carcinomas immunohistochemically with antibodies against E-cadherin and ß-catenin. Survival analyses were done.RESULTS: E-cadherin expression was focally retained in the tumour cell membranes and the tumour cell cytoplasm of the papillary, follicular and oncocytic thyroid cancers, weather in anaplastic cancers it was almost lost (p = 0.0042, and ? = 0.019, respectively, Fisher's Exact Test). The expression of ß-catenin in tumour cytoplasm and membrane in papillary cancers was higher as compared to that in the other tumours (p = 0.111, and ? = 0.0104, respectively).CONCLUSION: Not surprisingly, the presence of aberrant expression of E-cadherin and ß-catenin in thyroid cancer has been associated with better patients' prognosis and better differentiated tumour histology.