Outcomes and Role of Lymphadenectomy in Hypervascular Intrahepatic Cholangiocarcinoma Based on CT‐Vascularity

ABSTRACT Background This study aimed to evaluate the outcomes and role of lymphadenectomy in hypervascular intrahepatic cholangiocarcinoma (ICC) quantified using the arterial phase of contrast‐enhanced computed tomography (CT). Methods Consecutive patients with mass‐forming (MF) or predominantly MF type ICC who underwent surgical resection from 2000 to 2019 were retrospectively analyzed. Using the image of the late arterial phase, CT‐vascularity was calculated by dividing the CT value of the tumor (Hounsfield units) with that of the liver parenchyma. According to the CT‐vascularity, patients were divided into hypervascular (CT‐vascularity > 1) and non‐hypervascular (CT‐vascularity ≤ 1) groups. Clinicopathologic features and survival outcomes were compared between the two groups. Further, the prognostic impact of lymphadenectomy was assessed in the hypervascular group. Results Of the 135 patients with MF‐ICC, the hypervascular group, and non‐hypervascular group comprised 47 (34.8%) and 88 patients (65.2%), respectively. The hypervascular group displayed clinical features typically associated with hepatocellular carcinoma (HCC) (i.e., viral hepatitis or history of HCC) and less aggressive tumor characteristics such as lower proportions of regional lymph node metastasis. The overall survival (OS) and recurrence‐free survival (RFS) of the hypervascular group were significantly better than those of the non‐hypervascular group (all, p < 0.001), and these results were retained after adjusting for known prognostic factors. Further, implementation of lymphadenectomy was not associated with benefit for OS and RFS in the hypervascular group ( p = 0.819, p = 0.912). Conclusion Hypervascular ICC itself represents a favorable prognosis, and there is a possibility of omitting lymphadenectomy in this subgroup.