Resection margin status at the portomesenteric axis may not determine oncologic outcome after pancreaticoduodenectomy for lymph node-positive pancreatic ductal adenocarcinoma.

ABSTRACT

BACKGROUND: Lymph node and resection margin status are associated with oncologic outcomes after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. However, surgical radicality at the portomesenteric axis in case of suspected infiltration remains controversial. METHODS: Clinicopathological data of patients who underwent a partial or total pancreaticoduodenectomy for PDAC between 2012 to 2019 in 2 major hepato-pancreato-biliary centers in Germany and Switzerland were assessed. We evaluated the impact of positive resection margins at the vascular, parenchymal, and retropancreatic surfaces on overall survival in patients with and without lymph node involvement. Margin-positive vascular resection included both patients with positive margins at the vascular groove and the resected venous wall. RESULTS: During the study period, 217 patients underwent partial/total pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. After excluding 7 patients suffering postoperative complications resulting in mortality within 90 days after surgery (3%), 169 patients had lymph node involvement (80%). In the entire study cohort, margin-positive resection (33%) was significantly associated with worse overall survival (3-year overall survival margin-positive resection 27% vs margin-negative resection 43%, P = .014). Among patients with positive lymph nodes, margin-positive vascular resection (n = 48, 28%) was not significantly associated with impaired overall survival (3-year overall survival margin-positive vascular resection 28% vs margin-negative vascular resection 36%, P = .065). On the contrary, margin-positive parenchymal resection (n = 7, 4%) (3-year overall survival margin-positive parenchymal resection 0% vs margin-negative parenchymal resection 35%, P < .0001) and margin-positive retropancreatic resection (n = 21, 12%) (3-year overall survival margin-positive retropancreatic resection 6% vs margin-negative retropancreatic resection 39%, P < .0001) significantly diminished overall survival in univariate and multivariate analysis in all patients. Among patients without lymph node involvement (n = 41, 20%), there were no margin-positive parenchymal or margin-positive retropancreatic resections. In contrast, only 5 patients had margin-positive vascular resection (12%), with overall survival compared to those with margin-negative vascular resection. CONCLUSIONS: In patients with pancreatic ductal adenocarcinoma and lymph nodal positivity, resection status at the parenchymal and retropancreatic surface but probably not at the portal and/or superior mesenteric vein is a determinant of survival. Therefore, margin-negative resection should be pursued during pancreaticoduodenectomy. However, radical venous resection and/or reconstruction for suspected tumor infiltration may not be necessary for patients with intraoperatively detected lymph node metastases.