Tumor infiltration in the medial resection margin predicts survival after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.

Background: Microscopic tumor involvement (R1) in different surgical resection margins after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) has been debated.

Methods: Clinico-pathological data for 258 patients who underwent PD between 2001 and 2010 were retrieved from a prospective database. The rates of R1 resection in the circumferential resection margin (pancreatic transection, medial, posterior, and anterior surfaces) and their prognostic influence on survival were assessed.

Results: For PDAC, the R1 rate was 57.1% (48/84) for any margin, 31.0% (26/84) for anterior surface, 42.9% (36/84) for posterior surface, 29.8% (25/84) for medial margin, and 7.1% (3/84) for pancreatic transection margin. Overall and disease-free survival for R1 resections were significantly worse than those for R0 resection (17.2 vs. 28.7 months, P = 0.007 and 12.3 vs. 21.0 months, P = 0.019, respectively). For individual margins, only medial positivity had a significant impact on survival (13.8 vs. 28.0 months, P < 0.001), as opposed to involvement in the anterior (19.7 vs. 23.3 months, P = 0.187) or posterior margin (17.5 vs. 24.2 months, P = 0.104). Multivariate analysis demonstrated R0 medial margin was an independent prognostic factor (P = 0.002, HR = 0.381; 95% CI 0.207-0.701).

Conclusions: The medial surgical resection margin is the most important after PD for PDAC, and an R1 resection here predicts poor survival.