[A clinical study about applying different R1 criteria to evaluate pancreatic head ductal adenocarcinoma specimens]

To analyze the R1 rate of the pancreatic head carcinoma resection specimens which delt with a unified protocol by two different R1 criteria.

Between November 2011 and October 2013, a unified pathological protocol was prospectively used to handle 70 consecutive pancreatioduodenectomy specimens for pancreatic ductal adenocarcinoma. Apart from the pancreatic transection margin, the bile duct and stomach/jejunum margins, different colors were used to stain the anterior surface, the superior mesenteric vein (SMV) groove margin, the superior mesenteric artery (SMA) margin, and the posterior surface. Axial slicing technique was used to dissect the pancreatioduodenectomy specimens.

Among the 70 patients, 3, 30 and 37 patients were classified as well, moderately and poorly differentiated respectively;7, 15 and 48 patients were classified as pT1, pT2 and pT3 respectively.Forty patients (57.1%) had metastases in regional lymph nodes (pN1) , and 16 patients (22.9%) had metastases in para-aortic nodes.Resection of the portal vein and/or the superior mesenteric vein was performed in 13 patients (18.6%) .When applying the UICC criteria, 26 cancer resections were classified R1 (37.1%) , 33 margins were turned out to be R1. The SMV groove margin and SMA margin were infiltrated in 13 specimens (13/33, 39.4%) respectively.When applying the Royal College of Pathologist's criteria, 39 cancer resections were classified R1 (55.7%) , 51 margins were turned out to be R1. The SMV groove margin and SMA margin were infiltrated in 18 (18/51, 35.3%) and 19 (19/51, 37.3%) specimen respectively.Until April 2014, the median follow-up was 18(range 6-42) months.

Applying the unified protocol for pancreatic head ductal adenocarcinoma specimens results in an significant R1 rate of the resection margins, and the R1 rate is related to the R1 criterion. The SMV groove margin and SMA margin are the two most frequent sites of R1.