Prognostic significance of involvement of the circumferential resection margin/surface in patients with pancreatic head cancer: A prospective evaluation of pancreatoduodenectomy specimens using the 0 and 1mmrules.

BACKGROUND/OBJECTIVES: The prognostic significance of circumferential resection margin (CRM) or circumferential surface (CS) in pancreatic head cancer is controversial. We investigated the survival outcomes according to CRM or CS involvement in pancreatoduodenectomy specimens of pancreatic ductal adenocarcinoma (PDAC).

METHODS: A total of 102 pancreatoduodenectomy specimens after upfront surgery for PDAC between 2014 and 2018 were prospectively collected. The superior mesenteric vein/portal vein or superior mesenteric artery margins were classified as CRM, and the anterior or posterior surfaces as CS. Survival outcomes and recurrence were compared according to the CRM/CS status, which was categorized into R10mm , R11mm , and R0 (≥1 mm) by the 0 and 1 mm rules.

RESULTS: For CRM, R10mm had significantly lower overall survival (OS) (P < 0.001) and disease-free survival (P < 0.001) rates than R11mm and R0, with no difference between R11mm and R0. For CS, R0 had a significantly higher OS rate (P < 0.001) than R10mm and R11mm , with no difference between R10mm and R11mm . In multivariable analysis, R10mm CRM was an independent risk factor for OS (hazard ratio 2.410, P = 0.003) and DFS (hazard ratio 5.019, P < 0.001). When CRM/CS were analyzed separately, only the R10mm superior mesenteric artery margin was significantly associated with local recurrence (P = 0.012).

CONCLUSIONS: The results suggest that CRM involvement defined by the 0 mm rule is more appropriate than the 1 mm rule for predicting survival outcomes, but CS involvement defined by the 0 or 1 mm rules is not prognostically significant.