Association of EGFR and GLI1 gene expression with clinicopathological features in papillary thyroid cancer

The epidermal growth factor receptor (EGFR) is a key component of molecular pathways associated with the progression of papillary thyroid cancer (PTC). Glioma-associated oncogene (GLI) gene expression induced by the Hedgehog (Hh) signaling pathway is associated with poor clinical outcomes in PTC. In this study, we focused on exploring the association between GLI1 and EGFR gene expression in PTC and clinical-pathological parameters, as well as the importance of their correlations. EGFR and GLI1 gene expression levels were analyzed in paraffin-embedded tumor tissues from 125 patients. Peritumoral non-tumoral thyroid tissues from the same patients were available and used as control samples in 33 cases. We examined the correlation between EGFR and GLI1 gene expression and evaluated their relationship with clinical-pathological parameters. EGFR and GLI1 gene expression levels were upregulated in tumor tissues and showed a significant inverse correlation ( r = − 0.589, p < 0.001). EGFR and GLI1 expression levels did not show significant associations with most clinicopathological parameters. However, GLI1 expression was significantly associated with microscopic extrathyroidal extension ( p = 0.010). ROC analysis showed that GLI1 may have discriminatory value for aggressive clinicopathological features, while EGFR showed limited performance across all parameters. Our findings suggest that GLI1, as a key effector of the Hh pathway, showed modest discriminatory ability for features associated with tumor aggressiveness in PTC. Further research is warranted to explore its therapeutic implications.