Lymph node dissection in clinically node-negative intrahepatic cholangiocarcinoma: a systematic review and meta-analysis.

BACKGROUND: Lymph node dissection (LND) in clinically node-negative (cN0) intrahepatic cholangiocarcinoma (iCCA) remains controversial. While LND improves staging accuracy, its survival benefit in cN0-iCCA is uncertain. METHODS: This systematic review and meta-analysis followed PRISMA 2020 guidelines (PROSPERO registration: CRD420251050907). PubMed, Scopus, and Cochrane Library were searched through May 2025 for studies comparing curative-intent liver resection with or without LND in cN0-iCCA. Risk of bias was assessed using the Newcastle-Ottawa Scale, and meta-analysis was conducted using a random-effects model. RESULTS: Five retrospective studies comprising 1,290 patients (507 LND, 783 non-LND) were included. The pooled analysis showed a non-significant trend toward improved OS in the LND group (HR = 0.80, 95% CI: 0.56-1.15; I² = 77.17%). Subgroup analysis including only low-risk-of-bias studies (Newcastle-Ottawa Scale ≥ 7) demonstrated a significant survival benefit (HR = 0.71, 95% CI: 0.52-0.98; I² = 61.09%). For DFS, the pooled HR was 0.93 (95% CI: 0.63-1.38; I² = 74.77%). In the low-risk-of-bias subgroup, a trend toward improved DFS was observed (HR = 0.81, 95% CI: 0.51-1.28; I² = 67.29%), though not statistically significant. LND did not increase major postoperative complications (OR = 0.97, 95% CI: 0.68-1.38). However, considerable heterogeneity was observed across included studies (I² >70%), reflecting differences in patient selection, surgical extent, and definitions of clinically node-negative disease; therefore, these results should be interpreted with caution. CONCLUSION: LND may improve survival in selected patients with cN0-iCCA without increasing postoperative risk. However, the evidence is limited by retrospective design and heterogeneity. Prospective studies are warranted to confirm these findings. No funding was received.