Clinical implications and optimal extent of lymphadenectomy for intrahepatic cholangiocarcinoma: A multicenter analysis of the therapeutic index

Aims Lymph node metastases (LNM) are associated with lethal prognosis in intrahepatic cholangiocarcinoma (ICC). Lymphadenectomy is crucial for accurate staging and hopes of possible oncological treatment. However, the therapeutic implications and optimal extent of lymphadenectomy remain contentious. Methods To clarify the prognostic value and optimal extent of lymphadenectomy, the therapeutic index (TI) for each lymph node was analyzed for 279 cases that had undergone lymphadenectomy in a multi‐institutional database. Tumor localization was divided into hilar lesions (n = 130), right peripheral lesions (n = 60), and left peripheral lesions (n = 89). In addition, the lymph node station was classified as Level 1 (LV1: hepatoduodenal ligament node), Level 2 (LV2: postpancreatic or common hepatic artery nodes), or Level 3 (LV3: gastrocardiac, left gastric artery, or celiac artery nodes). Results Lymph node metastases were confirmed in 109 patients (39%). Five‐y survival rates were 45.3% for N0 disease, 27.1% for LV1‐LNM, 22.9% for LV2‐LNM, and 7.3% for LV3‐LNM (P 5.0 in LV1 and LV2, whereas bilateral peripheral lesions showed 5‐year TI > 5.0 in LV1. Conclusion The implications and extent of lymphadenectomy for ICC appear to rely on tumor location. In the peripheral type, the benefit of lymphadenectomy would be limited and dissection beyond LV1 should be avoided, while in the hilar type, lymphadenectomy up to LV2 could be recommended. Lymph node metastases are lethal prognostic factors in intrahepatic cholangiocarcinoma (ICC). Lymphadenectomy is crucial for accurate staging and hoped‐for as possible oncological treatment in ICC. A prognostic value of lymphadenectomy could be proven by analysis of the therapeutic index, especially in the hilar type. Lymphadenectomy should be a minimal requirement for the multimodal treatment of ICC. The implication and extent of lymphadenectomy for ICC should rely on tumor location.