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

Background/purpose: 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).

Methods: 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.

Results: 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.

Conclusion: cHCC-CCA is associated with high risk of recurrence following surgical resection as compared with HCC. Closely post-operative monitoring is highly recommended.