Should lymphadenectomy performed routinely in patients with primary intrahepatic cholangiocarcinoma undergoing curative hepatectomy? A retrospective cohort study with propensity-score matching analysis

BACKGROUND: The benefit of routine lymphadenectomy (LD) in improving outcomes for patients with primary intrahepatic cholangiocarcinoma (ICC) undergoing curative hepatectomy remains unclear. MATERIALS AND METHODS: This study enrolled 269 consecutive patients who underwent liver resection for primary ICC from January 2009 to July 2020 in West China Hospital. The association of the nodal status with disease-free survival (DFS) and overall survival (OS) was analyzed using the Cox proportional hazards model and 1:1 propensity score matching (PSM) analysis. RESULTS: Seventy-five (27.9%) patients underwent curative liver resection combined with LD (LD+ group), while 194 (72.1%) patients received curative liver resection without LD (LD- group and Nx group). Among the LD+ group, metastatic disease was present in 36 patients (48%, N1 group) and absent in 39 patients (N0 group). During the follow-up period, 116 patients (43.1%) experienced tumor recurrence and 101 patients (37.5%) died due to recurrence. Multivariate analysis revealed that lymph node metastasis (N1, HR 3.682, 95% CI 1.949–6.957, p < 0.001) was associated with worse OS, while LD+ status (HR 0.504, 95% CI 0.298–0.853, p = 0.011) was associated with improved OS. Adjuvant therapy was a protective factor for both DFS (HR 0.602, 95% CI, 0.447–0.810, p = 0.001) and OS (HR 0.683, 95% CI 0.484–0.963, p = 0.030). After 1:1 PSM, the LD+ patients (n = 74) displayed similar 1-, 3- and 5-year DFS rates (40.0, 7.9 and 7.9% vs. 29.0, 13.7 and 13.7%, p = 0.741) and OS rates (56.0, 26.6 and 22.2% vs. 58.9, 25.6, and 16.4%, p = 0.644) to the LD- patients (n = 74). Additionally, among the 75 LD+ patients, 48 patients underwent hepatic hilar lymphadenectomy (HHL), and 27 patients underwent extended hepatic hilar lymphadenectomy (EHL). Both DFS (p = 0.504) and OS (p = 0.215) were similar between the HHL and EHL groups. CONCLUSION: Routine LD and adjuvant therapy may contribute to improved OS according to the crude analysis. LD could provide accurate staging without excessive risk and guide adjuvant therapy based on the tumor stage, potentially resulting in better survival. These results suggest that a routine LD should be considered during curative hepatectomy for ICC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12893-023-02255-5.