Objective: To identify the predictors of unresectable proximal cholangiocarcinoma in era of modern imaging.

Materials and Methods: Between January 2012 and April 2017, patients who had potentially curative resection and underwent laparotomy for proximal cholangiocarcinoma were evaluated. The 60 patients were categorized into two groups, resectable and unresectable group.

Results: For an intrahepatic cholangiocarcinoma [ICC] group of 18-unresectable and 27-resectable patients, there were significantly higher levels of alkaline phosphatase [ALP] (328.4 versus 148.8 U/L, p = 0.002), gamma-glutamyl transferase [GGT] (364.1 versus 179.9U/L, p = 0.015) and a higher number of patients with N2-enlarged lymph nodes [LN] greater than 1 cm from imaging (27.8% versus 0%, p = 0.004) in unresectable group. For a perihilar cholangiocarcinoma [PHC] group of 5-unresectable and 10-resectable patients, there was a higher number of patients with N2-enlarged LN greater than 1 cm from imaging (40.0% versus 0%, p = 0.032) in unresectable group. According to univariate analysis, ALP and GGT of resectable group and unresectable group were significantly different by using cut-off level of ALP at 150 U/L (odds ratio 0.240, p = 0.028) and GGT level at 240 U/L (odds ratio 0.154, p = 0.005). The GGT was the only one independent predictor by using cut-off level at 240 U/L (odds ratio 0.154, p = 0.13). The area under the receiver operating characteristic [ROC] curve of GGT was 0.7127.

Conclusion: The GGT was the moderate powerful predictor of unresectable patients for ICC in patients with high a serum level of GGT more than 240 U/L.

Keywords: Intrahepatic cholangiocarcinoma, Perihilar cholangiocarcinoma, Cholangiocarcinoma, Unresectable