The impact of tumor location on the value of lymphadenectomy for intrahepatic cholangiocarcinoma

Background: The therapeutic role of lymphadenectomy (LND) for intrahepatic cholangiocarcinoma (ICC) patients remains ill-defined. We sought to analyze the therapeutic value of LND relative to tumor location and preoperative lymph node metastasis (LNM) risk. Methods: Patients who underwent curative-intent hepatic resection of ICC between 1990 and 2020 were included from a multi-institutional database. Therapeutic LND (tLND) was defined as LND that harvested ≥3 lymph nodes. Results: Among 662 patients, 178 (26.9%) individuals received tLND. Patients were categorized into central type ICC (n = 156, 23.6%) and peripheral type ICC (n = 506, 76.4%). Central type harbored multiple adverse clinicopathologic factors and worse overall survival (OS) compared with peripheral type (5-year OS, central: 27.0% vs. peripheral: 47.2%, p < 0.001). After consideration of preoperative LNM risk, patients with central type and high-risk LNM who underwent tLND survived longer than individuals who did not (5-year OS, tLND: 27.9% vs. non-tLND: 9.0%, p = 0.001), whereas tLND was not associated with better survival among patients with peripheral type ICC or low-risk LNM. The therapeutic index of hepatoduodenal ligament (HDL) and other regions was higher in central type than in peripheral type, which was more pronounced among high-risk LNM patients. Conclusions: Central type ICC with high-risk LNM should undergo LND involving regions beyond the HDL.