The Clinicopathological Characteristics and Prognosis of Cholangiolocarcinoma: A Multicenter Study With a Central Pathology Review
Takamichi Ishii, Kenta Makino, Etsuro Hatano, Mina Komuta, Jun Akiba, Yoshihiro Sakamoto, Shun‐Ichi Ariizumi, Goro Honda, Toru Hisaka, Yutaka Takeda, Akira Shimizu, Kentaro Yasuchika, Takashi Mizuno, Daisuke Asano, Atsushi Fujio, Naoto Gotohda, Chie Kitami, Koji Amaya, Hiroshi Sadamori, Manabu Kawai, Akiyoshi Nakakura, Masafumi Nakamura, Itaru EndoABSTRACT
Background
Cholangiolocarcinoma (CLC) is a rare liver cancer with ≥ 80% ductular configuration (DC). Given its rarity, its clinicopathological characteristics remain poorly understood, and its status as a distinct disease entity remains controversial. We conducted a nationwide multicenter study with centralized pathological review to investigate the features of CLC.
Methods
We included patients with a postoperative diagnosis of CLC at 49 participating institutions (2005–2018). All cases were re‐evaluated by centralized pathology according to the WHO classification.
Results
Among 196 re‐evaluated patients, 56 tumors were classified as CLC, 69 as intrahepatic cholangiocarcinoma (iCCA) with < 80% DC, 53 as small‐duct type iCCA with DC, and 16 as mixed small‐ and large‐duct type (SD/LD‐iCCA with DC). CLC showed a low prevalence of viral hepatitis (23.2%), frequent arterial enhancement (83.9%), and characteristic apical EMA positivity. The median overall survival (OS) was 10.8 years, with 5‐ and 10‐year OS rates of 85.0% and 73.7%, respectively, which were significantly better than those of SD/LD‐iCCA with DC. Recurrence occurred in 38.2% of CLC cases with favorable outcomes following surgical resection.
Conclusions
CLC exhibits distinct pathological and prognostic features, including favorable long‐term survival, supporting CLC as a distinct clinicopathological entity. Further molecular research is needed to refine the classification.
Trial Registration
This study was registered with the UMIN Clinical Trials Registry (UMIN000057919)