The impact of lymph node dissection on the prognosis of patients with intrahepatic cholangiocarcinoma.

e16313 Background: Intrahepatic cholangiocarcinoma (ICC) makes up ~20% of liver cancers. Radical resection is the sole potential cure, with lymph node metastasis as a key prognostic factor. However, routine lymph node dissection's necessity is debated, and clinical evidence on its role and impact in ICC is limited. This study explores routine lymph node dissection's effects, focusing on non-metastatic lymph node removal. Methods: We analyzed clinical and prognostic data from 849 ICC patients who underwent liver resection (2012-2021), excluding those with combined hepatocellular-cholangiocarcinoma, preoperative extrahepatic metastases, or neoadjuvant therapy. Patients were divided into Group I (no dissection, n = 345), Group II (dissection, negative metastasis, n = 337), and Group III (dissection, positive metastasis, n = 167). Survival rates were evaluated using Kaplan-Meier analysis, with Cox regression and log-rank tests for statistical analysis. Results: Significant OS and RFS differences were seen among the three groups (OS: P = 0.002, P < 0.0001; RFS: P = 0.001, P < 0.0001). Group I had the best prognosis (mOS and mRFS > 60 months), Group II followed (mOS: 50.83, mRFS: 30.00 months), and Group III had the worst outcomes (mOS: 19.00, mRFS: 17.27 months). Multivariate analysis identified lymph node dissection as an independent risk factor for OS (P = 0.008) and RFS (P = 0.01) in lymph node-negative patients, associated with poorer outcomes. Among patients without lymph node metastasis, adjuvant chemotherapy showed no significant differences in OS and RFS between Group I and Group II (all P > 0.05). However, adjuvant PD-1/PD-L1 treatment significantly improved OS and RFS in Group I compared to Group II (mOS: > 60.00 vs. 36.77 months, P = 0.039; mRFS: 27.60 vs. 11.87 months, P = 0.005). In adjuvant chemotherapy-treated patients, Group II had better OS and RFS than Group III (mOS: > 60.00 vs. 38.83 months, P = 0.020; mRFS: > 60.00 vs. 19.03 months, P = 0.008). Adjuvant PD-1/PD-L1 therapy showed no significant OS or RFS differences between Group II and Group III (mOS: 39.10 vs. 38.83 months, P = 0.592; mRFS: 16.92 vs. 23.23 months, P = 0.795). In Group II, patients receiving adjuvant chemotherapy had better OS (P = 0.006) and RFS (P = 0.049) than those without. However, immunotherapy had little impact on OS and RFS (mOS: 39.10 vs. 40.00 months, P = 0.594; mRFS: 16.92 vs. 16.33 months, P = 0.942). Conclusions: For resectable ICC patients without lymph node metastasis, lymph node dissection increases postoperative tumor recurrence, reduces OS, and does not improve prognosis for those receiving postoperative chemotherapy. It may also adversely affect outcomes in patients undergoing postoperative immunotherapy. Similarly, for patients with lymph node metastasis, lymph node dissection does not enhance prognosis. These findings indicate that removing non-metastatic lymph nodes may negatively impact outcomes, suggesting the preservation of unaffected lymph nodes during surgery is advisable.