To investigate the clinicopathological features, survival and prognosis of patients with hilar cholangiocarcinoma (hCCA) and hilar-type intrahepatic cholangiocarcinoma (hICC), aiming to provide references for differential diagnosis and surgical plan in clinical diagnosis and treatment.

Clinical data of 158 patients with cholangiocarcinoma admitted to the Affiliated Hospital of North Sichuan Medical College from January 2015 to December 2021 were retrospectively analyzed. The informed consents of all patients or their families were obtained and the local ethical committee approval was received. Among them, 58 patients were male and 100 female, aged from 32 to 85 years, with a median age of 62 years, 90 cases of hICC and 68 hCCA. Baseline data, laboratory examination, surgical records, pathological examination reports and other potential prognostic factors were collected. Postoperative outpatient follow-up was conducted to record the survival time of patients. Clinicopathological features of all patients were compared by t-test, Wilcoxon rank-sum test, Chi-square test or Fisher's exact test. Survival analysis was performed by Kaplan-Meier method and Log-rank test.

Compared with hCCA, CA19-9 level was higher (Z=2.712, P<0.05), tumor diameter was larger (Z=-2.457, P<0.05), the incidence of satellite lesions was higher (χ²=4.621, P<0.05) and AJCC T staging was later in hICC patients (χ²=10.109, P<0.05). However, the level of bilirubin was higher (Z=2.549, P<0.05), and the proportion of preoperative biliary drainage was higher in hCCA patients (χ²=4.594, P<0.05). Compared with hCCA, hICC patients were more inclined to adopting extended hepatectomy, including left and right hepatectomy or left and right trihepatectomy (χ²=10.681, P<0.05). The portal vein resection rate was higher in hICC patients (χ²=5.274, P<0.05). The patients were followed up for 0.2-57.4 months, with a median follow-up time of 18 months. During postoperative follow-up, 43 hICC patients and 15 hCCA patients died. The median overall survival (OS) of patients with hICC and hCCA was 23.8 and 44.9 months, and the difference was statistically significant (χ²=8.324, P=0.004).

Compared with hCCA, hICC patients have advanced clinicopathological features, more aggressive biological behavior and worse prognosis. It is of clinical significance to differentially diagnose hICC from hCCA, determine treatment regimens and predict clinical prognosis of hICC and hCCA patients.