Lymph node dissection for intrahepatic cholangiocarcinoma: a critical review of the literature to date.

Definite policy or evidence in regards to the lymph node dissection (LND) for intrahepatic cholangiocarcinoma (ICC) does not exist at present. We review and summarize the current knowledge about LND for ICC in reference to the literature to date. A Pubmed search was done to find the relevant literature. Only English literature from 2000 to 2013 was retrieved, using key words "intrahepatic cholangiocarcinoma" and "lymph node". In all selected articles, those which included a description of the difference in the survival results between the presence of lymph node metastasis (LNM), execution rate of LND, or institutional policy for LND were included in this review. In all reviewed articles, survival results of the LNM-positive group, evaluated by the 5-year survival rate, median survival time, or recurrence-free survival time were clearly worse than the LNM-negative group. However, the execution rate of LND was not often assessed, and therefore precise evaluation for the efficacy of LND is still controversial. Randomized controlled trials under the definite LND policy should be conducted to obtain precise survival results and clinical evaluation criteria for LND.