Prospective Evaluation of Resection Margins Using Standardized Specimen Protocol Analysis among Patients with Distal Cholangiocarcinoma and Pancreatic Ductal Adenocarcinoma

Purpose: Using a standardized specimen protocol analysis, this study aimed to evaluate the resection margin status of patients who underwent resection for either distal cholangiocarcinoma (DC) or pancreatic ductal adenocarcinoma (PDAC). This allowed a precise millimetric analysis of each inked margin. Methods: From 2010 to 2018, 355 consecutively inked specimens from patients with PDAC (n = 288) or DC (n = 67) were prospectively assessed. We assessed relationships between the tumor and the following margins: transection of the pancreatic neck, bile duct, posterior surface, margin toward superior mesenteric artery, and the surface of superior mesenteric vein/portal vein groove. Resection margins were evaluated using a predefined cut-off value of 1 mm; however, clearances of 0 and 1.5 mm were also evaluated. Results: Patients with DC were mostly men (64% vs. 49%, p = 0.028), of older age (68 yo vs. 65, p = 0.033), required biliary stenting more frequently (93% vs. 77%, p < 0.01), and received less neoadjuvant treatment (p < 0.001) than patients with PDAC. The venous resection rate was higher among patients with PDAC (p = 0.028). Postoperative and 90-day mortality rates were comparable. Patients with PDAC had greater tumor size (28.6 vs. 24 mm, p = 0.01) than those with DC. The R1 resection rate was comparable between the two groups, regardless of the clearance margin. Among the three types of resection margins, a venous groove was the most frequent in both entities. In multivariate analysis, the R1 resection margin did not influence patient survival in either PDAC or DC. Conclusion: Our standardized specimen protocol analysis showed that the R1 resection rate was comparable in PDAC and DC.

Automated summary

This study evaluated the resection margin status of patients with PDAC and DC using a standardized specimen protocol analysis. The R1 resection rate was comparable between the two groups, and venous groove was the most common type of resection margin. R1 resection margin did not influence patient survival in either group.