Angiogenesis and clinicopathologic characteristics in different hepatocellular carcinoma subtypes defined by EpCAM and α-fetoprotein expression status

Abstract

Recently, two hepatic lineage markers epithelial cell adhesion molecule (EpCAM) and α-fetoprotein (AFP) were used to classify hepatocellular carcinoma (HCC) into four subtypes with prognostic implication. In the present study, we further evaluated the clinicopathologic and angiogenic characteristics among these HCC subtypes. EpCAM expression was investigated by immunohistochemistry in 115 HCC primary tumors. Based on EpCAM immunostaining and serum AFP levels, 115 HCC cases were classified into four subtypes: EpCAM⁺AFP⁺ (26.1%), EpCAM⁻AFP⁺ (20.0%), EpCAM⁺AFP⁻ (20.8%), and EpCAM⁻AFP⁻ (33.1%). EpCAM⁺AFP⁺ and EpCAM⁻AFP⁺ HCC were associated with late TNM stages and high frequencies of venous invasion, whereas EpCAM⁺AFP⁻ and EpCAM⁻AFP⁻ subtypes were associated with early TNM stages and low frequencies of venous invasion. Furthermore, EpCAM⁺AFP⁺ HCC had a significantly higher microvessel density (MVD) and higher level of VEGF (Vascular epithelial growth factor) expression than the other three subtypes. In conclusion, our study indicated that subtype classification of HCC based on EpCAM and AFP status had clinicopathologic and biologic implications in aggressive phenotype and angiogenesis. We also suggest that the EpCAM⁺AFP⁺ HCC patients might be potential therapeutic candidates for anti-angiogenesis therapy.