Which Factors Are Associated With Positive Resection Margin in Pancreatic Ductal Adenocarcinoma for Different Surgical Procedures? Results Based on a Standard Pathological Evaluation System-retrospective Cohort Study 

Abstract

Background/Objectives: The present study identified the independent risk factors of R1 resection in pancreaticoduodenectomy (PD) and distal pancreatosplenectomy (DP) for patients with pancreatic ductal adenocarcinoma (PDAC).Methods：Consecutive patients who were operated from December 2017 to 2018 with curative intent were analyzed retrospectively. A standardized pathological examination with digital whole-mount slide images (DWMSIs) was utilized for the resection margin status. R1 was defined as microscopic tumor infiltration within 1 mm to the resection margin. The potential risk factors of R1 resection for PD and DP were analyzed separately by univariate and multivariate logistic regression analyses. Results：For the 240 patients who underwent PD, and the 142 patients who underwent DP, the R1 resection rates were 30.8% and 35.6 %, respectively. Univariate analysis on risk factors of R1 resection for PD were tumor location, absence of tumor necrosis, N staging, TNM staging, and surgical type of PD; while those for DP were nerve invasion, T staging, and TNM staging. Multivariate logistic regression analysis showed that the risk factors of R1 resection for PD were tumor location (neck vs. head; uncinate process vs. head) and N staging, while those for DP were T staging .Conclusions：The location of tumor in the neck and uncinate process, and N1/2 staging were independent risk factors of R1 resection for PD; while those for DP were T3/4 staging.