The Vessels That Encapsulate Tumor Clusters (VETC) Pattern Is a Poor Prognosis Factor in Patients with Hepatocellular Carcinoma: An Analysis of Microvessel Density

SIMPLE SUMMARY: Hepatocellular carcinoma has the characteristics of angiogenesis and neovascularization, which are the main steps in tumor growth and metastasis. The Vessels that encapsulate tumor clusters (VETC) pattern is a unique vascular structure in hepatocellular carcinoma. Microscopically, each tumor cluster is encapsulated by sinusoid-like vessels that form cobweb-like networks. Here, we retrospectively investigated the clinical–pathological features of hepatocellular carcinoma patients with or without the VETC pattern. We found that the VETC pattern is an independent factor of poor prognosis for long-term oncological outcomes. Meanwhile, higher intra-tumoral microvessel density was significantly associated with the VETC pattern. Further studies are needed to validate our findings. ABSTRACT: The outcomes of patients with hepatocellular carcinoma (HCC) are unsatisfactory because of its high recurrence rate. The Vessels that encapsulate tumor clusters (VETC) pattern is a unique vascular structure. In this study, we investigated the clinical–pathological features of HCC patients with the VETC pattern. We retrospectively reviewed patients with HCC who underwent curative hepatectomy at Chang Gung Memorial Hospital between 2007 and 2013. The form of the VETC pattern was established using an anti-CD31 stain. The results were classified into positive (VETC(+)) and negative (VETC(−)) patterns. We investigated and compared demographic data between these two groups. Overall, 174 patients were classified into either the VETC(+) or VETC(−) groups. The median followed-up period was 80.5 months. There were significant differences in the number of hepatitis B carriers, the occurrence of vascular invasion, tumor size, TNM staging, microvessel density, and recurrence (all p < 0.05). Regarding the prediction of disease-free survival, after COX regression multivariate analysis, VETC(+) remained independently associated with recurrent episodes (p = 0.003). The intra-tumoral microvessel density, demonstrated by CD-31, was the only clinical–pathological feature independently associated with VETC(+). Our study demonstrated that the VETC pattern is an independent factor of poor prognosis for DFS. Higher intra-tumoral microvessel density was significantly associated with the VETC pattern. Further studies are needed to validate our findings.