Prognostic Impact of Metastatic Lymph Node Numbers for Intrahepatic Cholangiocarcinoma

Abstract

Background: Lymph node (LN) metastasis in intrahepatic cholangiocarcinoma (ICC) is one of the poor prognostic factors after radical surgery. However, unlike other biliary tract malignancies, the nodal stage of ICC only reflects the presence of metastatic LN, not the number of metastatic LNs. This study aims to identify the prognostic impact of metastatic LN numbers in ICC. Methods: Data from 102 ICC patients who underwent hepatectomy with 5 or more harvested LNs and covering stations No. 12 and 8 from January 2006 to December 2019 were retrospectively reviewed. Hazard ratio (HR) according to increasing metastatic LN number was calculated with other known prognostic factors for ICC. Using the result, the patients were divided into 3 groups according to the number of metastatic LNs (N0 group (n=50): no metastatic LN, N+<4 groups (n=39): 1-3 metastatic LNs, N+≥4 group (n=13): ≥4 metastatic LNs) and disease-free survival (DFS) and overall survival (OS) were analyzed. Results: Metastatic LN numbers were prognostic factors of oncologic survival. (DFS; HR=1.18[1.06-1.30], p=0.002, OS; HR=1.22[1.09-1.37], p=0.001) In the survival analysis, significantly poor outcomes were shown with an increasing number of metastatic LNs. (DFS; N0 vs. N+<4 vs. N+≥4: 36.0[0.0-76.9] vs. 9.0[2.9-15.1] vs. 2.0[0.6-3.4] months, p>0.001, OS; N0 vs. N+<4 vs. N+≥4: 69.0[30.6-107.4] vs. 26.0[21.3-30.7] vs. 10.0[7.7-12.3] months, p>0.001) In the post hoc analysis, a significant difference between adjacent groups was shown. (DFS and OS; N+<4 vs. N+≥4: p<0.001). Conclusion: With proper LN dissection, the number of metastatic LNs is a prognostic factor of ICC.Tabled 1EP01C-061Disease-free survivalOverall survivalUnivariateMultivariateUnivariateMultivariateHR (95%CI)p-valueHR (95%CI)p-valueHR (95%CI)p-valueHR (95%CI)p-valueT stage0.2280.3450.3040.375T43.69 (0.91-14.93)0.0683.79 (0.89-16.18)0.0723.09 (0.76-12.52)0.1152.72 (0.63-11.84)0.182T32.72 (1.10-6.76)0.0312.23 (0.88-5.66)0.0922.64 (1.05-6.60)0.0382.29 (0.89-5.88)0.084T22.33 (0.97-5.62)0.0601.80 (0.73-4.46)0.2042.18 (0.90-5.32)0.0851.54 (0.61-3.89)0.360T1b1.93 (0.70-5.33)0.2041.61 (0.55-4.72)0.3901.86 (0.68-5.13)0.2301.40 (0.47-4.15)0.540T1a(Reference)(Reference)(Reference)(Reference)Metastatic LN1.25 (1.15-1.35)<0.0011.18 (1.06-1.30)0.0021.28 (1.17-1.40)<0.0011.22 (1.09-1.37)0.001 Open table in a new tab