Radiological features and outcomes of combined hepatocellular-cholangiocarcinoma in patients undergoing surgical resection

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer. Preoperative diagnosis of cHCC-CCA is difficult, and outcome of cHCC-CCA is obscured. Our study aimed to investigate the clinicopathological and radiological features of cHCC-CCA and compare their outcomes with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). From August 2010 to December 2017, 891 patients undergoing liver tumor resection in Taipei Veterans General Hospital, including 30 patients with pathology-proven cHCC-CCA, 819 HCC, and 42 ICC were retrospectively reviewed. Radiological features of contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) in patients with cHCC-CCA were reevaluated by a radiologist. Factors association with disease-free survival (DFS) and overall survival (OS) were analyzed. The mean age of cHCC-CCA, HCC and ICC was similar. Hepatitis B virus infection was prevalent in patients with cHCC-CCA (22/30, 73.3%). Most (70%) of the cHCC-CCA had atypical radiological pattern of HCC and belonged to classic type in pathological features. cHCC-CCA and ICC had worse DFS, but the 5-year OS of cHCC-CCA was substantial adequate after surgery. Of the 891 patients, male gender, advanced T stage, multiple tumor number, alpha-fetoprotein (AFP) level >20 ng/ml, cHCC-CCA, and ICC were factors associated with poor DFS in multivariable analysis. Older age, T stage 3 or 4, presence of macrovascular invasion, AFP >20 ng/mL, cHCC-CCA, and ICC were factors significantly associated with OS. cHCC-CCA is associated with high risk of recurrence following surgical resection as compared with HCC. Closely post-operative monitoring is highly recommended.