Impact of small duct- and large duct type on survival in patients with intrahepatic cholangiocarcinoma: Results from a German tertiary center.

ABSTRACT

BACKGROUND & AIMS: In recent years, histopathological characterization of intrahepatic cholangiocarcinoma revealed small duct type (SD-iCCA) and large duct type (LD-iCCA). Data on the prevalence of the subtypes are limited and highly varying. The aim of this study was to assess the prevalence of SD-iCCA and LD-iCCA and their impact on survival for the first time in a European cohort. MATERIALS AND METHODS: All patients with surgically resected iCCA diagnosed between December 2005 and December 2021 at the University Hospital Frankfurt were analyzed by an expert hepatobiliary pathologist. For overall survival (OS) and progression-free survival (PFS), Kaplan-Meier curves and Cox-regression analyses were performed. RESULTS: In total, 116 patients with surgically resected iCCA treated in our tertiary hospital were classified as SD-iCCA (73.3%, n = 85) and LD-iCCA (26.7%, n = 31). Subgroup analyses revealed median OS of 54.4 months (95% CI = 38.3 - 70.4 months) and 25.4 months (95% CI = 15.1 - 35.7 months) for SD-iCCA and LD-iCCA, respectively (p = 0.027). The median PFS for patients receiving gemcitabine-based chemotherapy with SD- and LD-iCCA was 8.4 months (95% CI = 4.7 - 12 months) and 3.3 months (95% CI = 1.8 - 4.7 months), respectively (p = 0.011). While LD-iCCA was as a significant risk factor of OS (HR = 1.7, 95% CI = 1 - 2.8, p = 0.031) in univariate analysis, it was not significant in multivariate analysis. CONCLUSION: In contrast to data from Asia, SD-iCCA is more prevalent than LD-iCCA in our cohort. LD-iCCA is associated with impaired OS after surgical resection and decreased PFS for patients receiving chemotherapy. These findings may suggest including the histological subtype in clinical routine diagnostics.