Predictive score for identifying intrahepatic cholangiocarcinoma patients without lymph node metastasis: a basis for omitting lymph node dissection.

Background: This study aimed to develop a predictive score for intrahepatic cholangiocarcinoma (ICC) in patients without lymph node metastasis (LNM) using preoperative factors.

Methods: A retrospective analysis of 113 ICC patients who underwent liver resection with systemic lymph node dissection between 2002 and 2021 was conducted. A multivariate logistic regression analysis was used as a predictive scoring system for node-negative patients based on the β coefficients of preoperatively available factors.

Results: LNM was observed in 36 patients (31.9%). Four factors were associated with LNM: suspicion of LNM on MDCT (odds ratio [OR] 13.40, p < 0.001), low-vascularity tumor (OR 6.28, p = 0.005), CA19-9 ≥500 U/mL (OR 5.90, p = 0.010), and tumor location in the left lobe (OR 3.67, p = 0.057). The predictive scoring system was created using these factors (assigning 3 points for suspected LNM on MDCT, 2 points for CA19-9 ≥500 U/mL, 2 points for low vascularity tumor, and 1 point for tumor location in the left lobe). A score cutoff value of 4 resulted in 0.861 sensitivity and a negative predictive value of 0.922 for detecting LNM. Notably, no patients with peripheral tumors and a score of ≤3 had LNM.

Conclusion: The developed scoring system may effectively help identify ICC patients without LNM.