The mesopancreas is the primary site for R1 resection in pancreatic head cancer: relevance for clinical trials

Abstract

PurposeThe prognosis of patients with pancreatic cancer remains poor, even after potentially curative R0 resection. This discrepancy may be due to the histopathological misclassification of R1 cases as curative resections (R0) in the past.Materials and methodsTo test this hypothesis, color coding of all resection margins and organ surfaces as part of a standardized histopathological workup was implemented and prospectively tested on 100 pancreatic head specimens.ResultsThirty-five patients were excluded from the analysis owing to the pathohistological diagnosis; only pancreatic ductal adenocarcinoma, distal bile duct adenocarcinoma, and periampullary adenocarcinoma were included. Applying the International Union Against Cancer criteria, 32 cancer resections were classified R0 (49.2%), while 33 cases turned out to be R1 resections (50.8%). The mesopancreas was infiltrated in 22 of the 33 R1 resection specimens (66.6%). It proved to be the only site of tumor infiltration in 17 specimens (51.5%). Applying the Royal College of Pathologists’ criteria, 46 resections were classified R1 (70.8%). As expected, the mesopancreas again was the most frequent site of noncurative resection (n = 27; 58.7%).ConclusionUsing the intensified histopathological workup for pancreatic head cancer specimens resulted in an increased rate of R1 resections and the mesopancreas represents the primary site for positive resection margins. Such results are of relevance for patients’ stratification in clinical trials.

Usefulness of Color Coding Resected Samples from a Pancreaticoduodenectomy with Tissue Marking Dyes for a Detailed Examination of Surgical Margin Surrounding the Uncinate Process of the Pancreas

“…In 2 reports on the subclassification of sites similar to the MUP 5,24 , sites similar to Area C or Area D or both showed a high frequency of a positive margin (57.6%…”

The concept and controversy of retroperitoneal nerve dissection in pancreatic head carcinoma (Review)

“…This explains why many patients with 'R0 resection' do not have long-term survival. For patients with pancreatic head cancer who underwent pancreaticoduodenectomy, the most common site of R1 residual cancer is in the 'mesopancreas' (51,52). Recently, total mesopancreas excision (TMpE) has been implemented and this may help to increase the R0 resection rate and to improve patient's prognosis (53).…”

Location of the meso-pancreatoduodenum as a regional lymphatic basin for pancreatic head carcinoma

“…Curative surgical resection is the main treatment modality contributing to good prognosis (1,2). Even following curative pancreaticoduodenectomy, however, numerous patients experience local recurrence around the superior mesenteric artery (SMA) margin (3,4), adversely affecting prognosis. Curative surgical resection requires control of tumor infiltration and lymph node metastasis.…”

“…The mesopancreas, is defined as the soft connective tissue located between the SMA and the uncinate process, or the structure situated to the right side of the SMA, and is regarded as the primary site of cancer cell infiltration (3,6,7). Excision of the entire mesopancreas can result in complete clearance of peripancreatic retroperitoneal tissue and improve the prognosis of patients with PHC.…”