Introduction : Differences in combined hepatocellular-cholangiocarcinomas (cHCC-CCAs) arising in high-risk patients with or without liver cirrhosis have not been elucidated. This study aimed to compare the clinicopathologic and imaging characteristics of cHCC-CCAs in patients with or without cirrhosis and to determine prognostic factors for recurrence-free survival (RFS) after curative resections of single cHCC-CCAs.

Methods : This retrospective study included 113 patients with surgically resected single cHCC-CCAs who underwent preoperative magnetic resonance imaging from January 2008 to December 2019 at two tertiary referral centers. Clinical, pathologic, and imaging features of tumors were compared in high-risk patients with or without cirrhosis. Imaging features were assessed using the Liver Imaging Reporting and Data System (LI-RADS) version 2018. RFS and associated factors were evaluated using Cox proportional hazards regression analysis, Kaplan-Meier analysis, and log-rank test.

Results : cHCC-CCAs arising from cirrhotic livers had a smaller mean tumor size (2.9 cm vs. 4.5 cm; p < 0.001) and were more frequently categorized as LR-5 or 4 (41.2% vs. 20.0%; p = 0.024) than those arising from non-cirrhotic livers. In multivariable analysis, a tumor size of > 3 cm (hazard ratio [HR], 2.081; 95% confidence interval [CI], 1.180–3.668; p = 0.011) and the LR-M category (HR, 2.302; 95% CI, 1.198–4.424; p = 0.012) were independent predictors associated with worse RFS.

Conclusions : The tumor size and distribution of LI-RADS categories of cHCC-CCAs differed in high-risk patients with or without cirrhosis. And LR-M category was a worse prognosis predictor after curative resections than LR-5 or 4 category.