Pathological Confirmation of Para-Aortic Lymph Node Status as a Potential Criterion for the Selection of Intrahepatic Cholangiocarcinoma Patients for Radical Resection with Regional Lymph Node Dissection

Para-aortic lymph node (PAN) metastasis traditionally has been defined as distant metastasis. Many studies suggest that lymph node metastasis in intrahepatic cholangiocarcinoma (ICC) is one of the strongest prognostic factors for patient survival; however, the status of the PAN was not examined separately from regional lymph node metastasis in these reports. Here, we investigated whether regional lymph node metastasis without PAN metastasis in ICC can be classified as resectable disease and whether curative resection can have a prognostic impact. Between 1998 and 2010, a total of 47 ICC patients underwent hepatic resection and systematic lymphadenectomy with curative intent. We routinely dissected the PANs and had frozen-section pathological examinations performed intraoperatively. If PAN metastases were identified, curative resection was abandoned. We retrospectively investigated the prognostic factors for patient survival after curative resection for ICC without PAN metastases, with particular attention paid to the prognostic impact of lymphadenectomy. Univariate analysis identified concomitant portal vein resection, concomitant hepatic artery resection, intraoperative blood loss, intraoperative transfusion, and residual tumor as significant negative prognostic factors. However, lymph node status was not identified as a significant prognostic factor. The 14 patients with node-positive cancer had a survival rate of 20 % at 5 years. Based on multivariate analysis, intraoperative transfusion was an independent prognostic factor associated with a poor prognosis (risk ratio = 4.161; P = 0.0056). Regional lymph node metastasis in ICC should be classified as resectable disease, because the survival rate after surgical intervention was acceptable when PAN metastasis was pathologically negative