Perioperative and long-term outcome of intrahepatic cholangiocarcinoma involving the hepatic hilus after curative-intent resection: comparison with peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma

Background: Intrahepatic cholangiocarcinoma with hepatic hilus involvement has been either classified as intrahepatic cholangiocarcinoma or hilar cholangiocarcinoma. The present study aimed to investigate the clinicopathologic characteristics and short- and long-term outcomes after curative resection for hilar type intrahepatic cholangiocarcinoma in comparison with peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma. Methods: A total of 912 patients with mass-forming peripheral intrahepatic cholangiocarcinoma, 101 patients with hilar type intrahepatic cholangiocarcinoma, and 159 patients with hilar cholangiocarcinoma undergoing curative resection from 2000 to 2015 were included from two multi-institutional databases. Clinicopathologic characteristics and short- and long-term outcomes were compared among the 3 groups. Results: Patients with hilar type intrahepatic cholangiocarcinoma had more aggressive tumor characteristics (eg, higher frequency of vascular invasion and lymph nodes metastasis) and experienced more extensive resections in comparison with either peripheral intrahepatic cholangiocarcinoma or hilar cholangiocarcinoma patients. The odds of lymphadenectomy and R0 resection rate among patients with hilar type intrahepatic cholangiocarcinoma were comparable with hilar cholangiocarcinoma patients, but higher than peripheral intrahepatic cholangiocarcinoma patients (lymphadenectomy incidence, 85.1% vs 42.5%, P <.001; R0 rate, 75.2% vs 88.8%, P <.001). After curative surgery, patients with hilar type intrahepatic cholangiocarcinoma experienced a higher rate of technical-related complications compared with peripheral intrahepatic cholangiocarcinoma patients. Of note, hilar type intrahepatic cholangiocarcinoma was associated with worse disease-specific survival and recurrence-free survival after curative resection versus peripheral intrahepatic cholangiocarcinoma (median disease-specific survival, 26.0 vs 54.0 months, P <.001; median recurrence-free survival, 13.0 vs 18.0 months, P =.021) and hilar cholangiocarcinoma (median disease-specific survival, 26.0 vs 49.0 months, P =.003; median recurrence-free survival, 13.0 vs 33.4 months, P <.001). Conclusion: Mass-forming intrahepatic cholangiocarcinoma with hepatic hilus involvement is a more aggressive type of cholangiocarcinoma, which showed distinct clinicopathologic characteristics, worse long-term outcomes after curative resection, in comparison with peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma.