Characteristics of intrahepatic cholangiocarcinoma according to tumor location.

Abstract

406 Background: Recently, the perihilar cholangiocarcinoma was defined as a tumor existing perihilar region between the right side of the umbilical portion of the left portal vein and the left side of the origin of the right posterior portal vein, in the General Rules for Clinical and Pathological Studies on Cancer of the Biliary Tract (The 6th edition). The study was aimed to investigate characteristics of intrahepatic cholangiocarcinoma (IHCC) according to tumor location. Methods: Study 1: Sixty-two IHCC patients who underwent hepatic resection were divided into the following 3 groups; peripheral type (n=41), perihilar type (n=10) and unclassified type (peripheral type with perihilar invasion: n=11). Clinicopathological data including CA19-9 and immnohistochemical staining of Ki67 and hypoxia inducible factor-1 (HIF-1) were compared. Study 2: The effect of 2 cycles of adjuvant gemcitabine combined with 5-FU and cisplatin (GFP) (Morine and Shimada. Hepatogastroenterology 2009) was retrospectively investigated, in advanced IHCC with one of 3 prognostic factors of LN metastasis, intrahepatic metastasis and R2 resection. Results: Study 1: There was no difference in background variables except for more frequent hilar biliary invasion in perihilar and unclassified types, and the largest tumor size in unclassified-type. The 5-year survival rate in the peripheral, perihilar and unclassified-types were 44%, 20% and 0%, respectively. In addition, CA19-9 level, Ki67 labelling index and positive rate of HIF-1 expression in the unclassified type were higher than those in other 2 types. Multivariate analysis revealed the unclassified type as an independent prognostic factor. Study 2: In 29 patients (47%) having one of the 3 prognostic factors, 9 patients including 4 unclassified-type IHCCs received the adjuvant GFP. The prognosis in GFP group tended to be better than that in non-GFP group (3-year survival rate: 38% vs. 6%, p = 0.07). Two patients with unclassified-type IHCC in non-GFP group died within 1 year after surgery. Conclusions: The unclassified-type IHCC indicated the most aggressive tumor biology, and the adjuvant GFP may be a useful strategy for such a highly malignant tumor with poor prognostic factors.