Introduction : The nodal stage of pancreatic ductal adenomcarcinoma is revised in AJCC 8th edition. Researches about prognosis of PDAC according to lymph nodes are still ongoing. We tried to find meaningful patterns of nodal involvement and reveal its clinical significance on overall survival.

Methods : We analyzed 848 patients, who received pancreatic head cancer surgery due to diagnosis of PDAC from January 2007 to December 2016, in the Samsung medical center. 516 Patients diagnosed with pancreatic head cancer were included. From pathologic reports, each lymph node stations are grouped to analyze the specific lymph node stations affecting the overall survival: peripancreatic lymph nodes (13 and 17, numbered by Japanese lymph node station); pericholedochal (12); hepatogastric (7,8,9); periduodenal (5,6) and superior mesenteric vessel (14). We conducted univariate and multivariate analysis using Cox proportional hazard regression test.

Results : 452 cases with metastatic lymph nodes were reviewed. T stage (p=0.014), N stage (p=0.027), cell differentiation (p=0.001), adjuvant treatment (p=0.001), nodal involvement around pericholedochal area (HR 1.561, 95% CI 1.112-2.189, p=0.010) and SMV (HR 2.246, 95% CI 1.302-3.873, p=0.004) are independent risk factors for overall survival. In the N1 category, nodal involvement around pericholedochal area and SMV resulted in worse survival than the otherwise patients (pericholedochal vs no pericholedochal, 14m vs 21m, p=0.008; SMV vs no SMV, 8m vs 21m, p=0.048).

Conclusions : Lymph node involvement around the pericholedochal area and SMV affected poor prognosis. Depending on the location of the lymph node metastasis, different surveillance policies will need to be considered in the future.