Prognostic significance of and risk prediction model for lymph node metastasis in resectable intrahepatic cholangiocarcinoma: do all require lymph node dissection?

Lymph node (LN) metastasis portends a worse prognosis following resection of intrahepatic cholangiocarcinoma (ICC); however, lymphadenectomy is not routinely performed, as its role remains controversial. Herein, we developed a risk model for LN metastasis by identifying its predictive factors and assessed a subset of patients who might not benefit from LN dissection (LND). 210 patients who underwent curative-intent surgery for ICC were retrospectively reviewed. A preoperative risk model for LN metastasis was developed following identification of its preoperative predictive factors using the recursive partitioning method. In the multivariable analysis, CA 19-9 level of >120 U/mL, an enlarged LN on computed tomography, and a tumor location abutting the Glissonean pedicles were independent predictors of LN metastasis. The preoperative risk model classified the patients according to their risk: high, intermediate, and low risks at a rate of LN metastasis on final pathology of 60.9%, 35%, and 2.3%, respectively. In the subgroup analysis among the low-risk patients, performance of LND had no survival advantage over non-performance of LND. Routine LND for preoperatively diagnosed ICC should be recommended to patients at an intermediate and a high risk of developing LN metastasis but may be omitted for low-risk patients.