Lymph node ratio after curative surgery for intrahepatic cholangiocarcinoma

Background: Intrahepatic cholangiocarcinoma (ICC) is rare but its incidence is rising world-wide. The value of lymph node dissection for ICC is under discussion; the current staging systems do not differentiate between numbers of involved nodes. Methods: Ninety-three patients who underwent laparotomy for ICC between 1997 and 2007 were identified retrospectively; 46 who underwent curative resection and systematic lymphadenectomy around the hepatoduodenal ligament were analysed further. Univariable and multivariable regression analysis was performed to identify prognostic factors. Results: Tumour size and advanced tumour stage were associated with worse overall and recurrence-free survival in univariable analysis. An increased ratio of positive to total harvested lymph nodes (LNR) was also prognostic for adverse outcome in lymph node-positive patients: crude hazard ratio 8.93 (95 per cent confidence interval (c.i.) 1.52 to 32.50) for overall survival and 8.76 (1.96 to 39.22) for recurrence-free survival. Adjusted hazard ratios for LNR in multivariable regression analysis were 9.81 (1.52 to 43.44) and 10.63 (2.04 to 55.31) respectively. The total number of retrieved lymph nodes was not related to survival or recurrence. Conclusion: LNR appears to be a good prognostic factor for survival or recurrence after curative resection for ICC.