Background/aims: The c-erbB-2 proto-oncogene is important for tumor invasiveness and metastases. Cyclooxygenase-2 (COX-2) plays an important role in carcinogenesis in several types of human cancer. The link between c-erbB-2 and COX-2 has been described in breast, colorectal, and prostate cancers. High levels of COX-2 have been detected in c-erbB-2-positive tumors. This observation suggests that c-erbB-2 mediates the induction of COX-2 gene transcription. In the present study, the expressions of c-erbB-2 and COX-2 in intrahepatic cholangiocarcinoma, their correlations with clinicopathologic parameters, and the relationship between their expressions were evaluated.
Methodology: Immunohistochemical staining for c-erbB-2 and COX-2 was performed in paraffin-embedded sections of fifty surgically obtained intrahepatic cholangiocarcinomas.
Results: The overexpression of c-erbB-2 was observed in 72% (36/50) of specimens. In groups with lymph node metastasis, distant metastasis and high TNM stage showed significantly lower expression. No significant correlation was found between c-erbB-2 overexpression and age, sex, tumor size, gross type, histologic grade, vascular invasion, or perineural invasion. The overexpression of COX-2 was observed in 40% (20/50) of specimens. COX-2 expression was not correlated with clinicopathologic parameters, except gross subtype. A positive correlation between c-erbB-2 and COX-2 expression was observed (p<0.05).
Conclusions: These results suggest that the c-erbB-2 is frequently overexpressed in intrahepatic cholangiocarcinomas, and its expression might play a role in regulating COX-2 expression.