Optimal lymph node examination and prognostic significance of positive lymph node ratio in distal cholangiocarcinoma: a multicenter cohort study of 852 patients

초록

Background: The optimal number of lymph nodes examined (LNE) during pancreaticoduodenectomy for distal bile duct cancer remains unclear. This study evaluated its impact on staging accuracy and the prognostic value of the positive lymph node ratio (PLR). Methods: We analysed 852 patients who underwent PD for histologically confirmed distal cholangiocarcinoma detection rates across LNE groups were compared by chi-square test. Overall survival (OS) was assessed using Kaplan–Meier and multivariable Cox regression. Results: Median LNE was 13 (IQR 7–19); 274 patients (32.2%) were node-positive (N1: 220, N2: 54). Node-positive detection increased with LNE (10.5% [LNE 1–3] to 47.0% [LNE ≥21]; p < 0.0001), with a threshold effect at LNE ≥12 (39.0% vs 23.2%; p < 0.001). Median OS was 73.8, 35.0, and 23.0 months for N0, N1, and N2, respectively (p < 0.001). Independent adverse prognostic factors were node-positive status, R1 margin, lymphovascular invasion, perineural invasion, poor differentiation, and age >60 years. PLR groups (<0.10, 0.10–0.25, ≥0.25) showed distinct median OS of 63.0, 32.0, and 22.0 months (p < 0.001). Conclusion: Examination of at least 12 LNs is recommended for accurate nodal staging in distal cholangiocarcinoma. The AJCC 8th edition three-tier N classification provides meaningful prognostic discrimination. © 2026 International Hepato-Pancreato-Biliary Association Inc.