Impact of histological tumor positive resection after pancreatoduodenectomy in patients with ductal adenocarcinoma and lymph node invasion

Abstract

Introduction: In patients with pancreatic ductal adenocarcinoma (PDAC), complete tumor resection (R0) has been proven to improve overall survival (OS). The present study aimed to compare OS after R0 and R1 resections among patients with PDAC and lymph node invasion who underwent pancreatoduodenectomy. Methods: All consecutive PDAC patients of our prospectively-maintained pancreas database who underwent pancreatoduodenectomy were retrospectively analyzed (2000-2015). Only patients without neoadjuvant treatment were included. R0 resection was defined as absence of microscopic cancer cells at resection margin (1-mm clearance requirement). OS was calculated using Kaplan-Meier method. Results: During the study period, 192 consecutive patients underwent upfront pancreatoduodenectomy. On histopathology, 165 patients had lymph node invasion (86%), while 27 had no lymph node invasion (14%). Among patients with lymph node invasion (n=165), 92 had R0 resection (56%), 61 R1 resection (37%), and 12 R2 resection (7%). The 12 R2 resections were excluded (median OS: 14 months). Preoperative characteristics and demographics of R0 and R1 groups were similar. Overall complication rates (Clavien II-V) were similar in both groups (53/92=58% vs. 41/61=67%, p=0.232). Median OS was 24 months for the R0 and R1 groups (p=0.725). Recurrence rate was 59% for the R0 group and 64% for the R1 group (p=0.533). Multivariate Cox proportional hazards model did not identify the R status or any other item as predictive factor for OS in patients with lymph node invasion. Conclusion: In PDAC patients who underwent upfront pancreatoduodenectomy without neoadjuvant treatment, the R status did not influence OS in case of lymph node invasion.