Proposal of a new staging system for intrahepatic cholangiocarcinoma: Analysis of surgical patients from a nationwide survey of the Liver Cancer Study Group of Japan

• Published in: Cancer Vol. 122; no. 1; pp. 61 - 70
• Main Authors: Sakamoto, Yoshihiro, Kokudo, Norihiro, Matsuyama, Yutaka, Sakamoto, Michiie, Izumi, Namiki, Kadoya, Masumi, Kaneko, Shuichi, Ku, Yonson, Kudo, Masatoshi, Takayama, Tadatoshi, Nakashima, Osamu
• Format: Journal Article
• Language: English
• Published: United States John Wiley and Sons Inc 01.01.2016
• Subjects: Bile Duct Neoplasms - epidemiology; Bile Duct Neoplasms - pathology; biliary invasion; Cholangiocarcinoma - epidemiology; Cholangiocarcinoma - pathology; Cohort Studies; Humans; intrahepatic cholangiocarcinoma; Japan - epidemiology; Multivariate Analysis; Neoplasm Staging - methods; Original; periductal invasion; Prognosis; staging system; Surveys and Questionnaires; Survival Rate; tumor size; Japan; biliary invasion; tumor size; staging system; periductal invasion; intrahepatic cholangiocarcinoma
• ISSN: 0008-543X; 1097-0142; 1097-0142
• DOI: 10.1002/cncr.29686

BACKGROUND In the current American Joint Committee on Cancer/International Union Against Cancer staging system (seventh edition) for intrahepatic cholangiocarcinoma (ICC), tumor size was excluded, and periductal invasion was added as a new tumor classification‐defining factor. The objective of the current report was to propose a new staging system for ICC that would be better for stratifying the survival of patients based on data from the nationwide Liver Cancer Study Group of Japan database. METHODS Of 756 patients who underwent surgical resection for ICC between 2000 and 2005, multivariate analyses of the clinicopathologic factors of 419 patients who had complete data sets were performed to elucidate relevant factors for inclusion in a new tumor classification and staging system. RESULTS Overall survival data were best stratified using a cutoff value of 2 cm using a minimal P value approach to discriminate patient survival. The 5‐year survival rate of 15 patients who had ICC measuring ≤2 cm in greatest dimension without lymph node metastasis or vascular invasion was 100%, and this cohort was defined as T1. Multivariate analysis of prognostic factors for 267 patients with lymph node‐negative and metastasis‐negative (N0M0) disease indicated that the number of tumors, the presence arterial invasion, and the presence major biliary invasion were independent and significant prognostic factors. The proposed new system, which included tumor number, tumor size, arterial invasion, and major biliary invasion for tumor classification, provided good stratification of overall patient survival according to disease stage. Macroscopic periductal invasion was associated with major biliary invasion and an inferior prognosis. CONCLUSIONS The proposed new staging system, which includes a tumor cutoff size of 2 cm and major biliary invasion, may be useful for assigning patients to surgery. Cancer 2016;122:61–70. © 2015 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. The current staging system for intrahepatic cholangiocarcinoma has been subject to debate. The authors developed a new staging system for intrahepatic cholangiocarcinoma using complete nationwide data from 419 surgical patients provided by the Liver Cancer Study Group of Japan.