Relationship Between Microvessel Count and Postoperative Survival in Patients with Intrahepatic Cholangiocarcinoma

Background  The present study aimed to elucidate the relationship between microvessel count (MVC) according to CD34 expression and prognosis in intrahepatic cholangiocarcinoma (ICC) patients who underwent hepatectomy based on our preliminary study. Methods  Relationships between MVC and clinicopathological factors were examined in 37 ICC patients. CD34 expression was analyzed using immunohistochemical methods. Results  Median MVC for ICC patients was 140/mm², which was applied as a cutoff value. Lower MVC was significantly associated with larger tumor size, periductal infiltrating type, and advanced Japanese tumor–node–metastasis stage (p < 0.05). Univariate survival analysis identified higher carcinoembryonic antigen level, periductal infiltrating type, poor histological differentiation, and lower MVC as significantly associated with lower 5-year survival rates. The 5-year survival rate in the higher-MVC group was significantly greater than that in the lower-MVC group (44% vs. 7%, p = 0.048). According to Cox multivariate survival analysis, only periductal infiltrating type on macroscopic examination was identified as a significant independent risk factor for poor survival after hepatectomy (risk ratio 4.8; p = 0.006), not MVC (1.1; p = 0.82). Conclusion  Tumor MVC might offer a useful prognostic marker of ICC patient survival after hepatectomy and further investigation in a larger series is warranted.