Co-overexpression of p53 protein and epidermal growth factor receptor in human papillary thyroid carcinomas correlated with lymph node metastasis, tumor size and clinicopathologic stage

Expressions of p53 protein and epidermal growth factor receptor (EGFR) were immunohistochemically investigated in 111 patients with papillary thyroid carcinomas (PTC) in order to evaluate their co-expression in relation to ly mph-node metastases (LNM), tumor size and clinicopathologic stage. In PTC, positive staining for p53 in dewaxed sections was present in nuclei or cyto plasm, or in both, whereas surface linear or cytoplasmic staining for EGFR was observed with varying degrees of extent and intensity. Positive reactio n (more than 10% of tumor cells positive) was observed in 65 cases (58.5%) for p53, and in 87 cases (78.4%) for EGFR. A significant correlation was fo und between p53 protein and EGFR overexpressions (p<0.01). Notably, p53-pos itive cases always exhibited positive staining for EGFR. Forty-four patient s (39.6%) exhibited concomitant LNM, most of-whom had both p53 and EGFR exp ression in primary foci. Statistical analysis revealed that co-expression o f p53 protein and EGFR was significantly correlated with LNM, tumor size an d clinicopathologic stage, but no correlation was found between their co-ex pression and age or sex. Our findings suggest that overexpression of p53 pr otein or EGFR in PTC tends to be associated with a high frequency of LNM, i ncreased tumor size and advanced clinicopathologic stage, and that co-expre ssion of both p53 protein and EGFR may predispose to growth and progression of PTC, Our findings also suggest that p53 protein and EGFR expressions ma y be clinicopathologic and prognostic indicators of PTC.