EXPRESSION OF C-MYC, TGF-ALPHA AND EGF-RECEPTOR IN SPORADIC MEDULLARY-THYROID CARCINOMA

In 20 patients with sporadic medullary thyroid carcinoma (MTC), immuno -histochemistry was used to localize the expression of the c-Myc oncop rotein, transforming growth factor alpha (TGF-alpha) and epidermal gro wth factor receptor (EGFR) and these three markers were analysed regar ding their relation to histopathological and histochemical Variables o f the tumours. The detection rates of c-Myc, TGF-alpha and EGFR were 9 0%, 90% and 95% respectively. Concomitant demonstration of the markers was reflected in significant associations (correlation factor between TGF-alpha and EGFR was 0.93, p < 0.001). The markers were almost inva riably located within the cytoplasm, which might suggest their crucial role in growth regulation and cell differentiation; this seems especi ally true of TGF-alpha and EGFR. The different markers showed no relat ion to either histopathological or histochemical variables (tumour beh aviour, tumour size, tumour cell type). The prominent co-expression of c-Myc, TGF-alpha and EGFR proteins indicates that in MTC these factor s might be of importance for tumour cell proliferation via autocrine g rowth stimulation.