Surgical margins for duodenopancreatectomy

Microscopic residual tumor (R1) affects prognosis of resected pancreatic head cancer patients. Surgeon's ability, caseload and accuracy of pathological staging affect the rate of R1 resections. The goal of this study was to verify if a standardized histopathological workup of the specimen affects the rate of microscopic residual tumor after PD for cancer. Two groups of specimens were managed with (Group 1, Standardized Group, SG) or without (Group 2, Non Standardized Group, NSG) a standardized histopathological workup reported by the Royal College of Pathologists. Group 1 included 50 cases of PD for periampullary cancer treated between October 2010 and July 2012. Group 2 included 50 cases of PD for periampullary cancer treated between September 2005 and September 2010. The primary endpoint of the study was to verify the differences in terms of R1 rate in the two groups. Correlation between presence/absence of microscopic residual tumor status and local recurrence was also evaluated. The cohort of 100 patients consisted of 66 pancreatic ductal adenocarcinoma (PDAC) (SG: 35; NSG: 31), 15 distal common bile duct cancer (SG: 9; NSG: 6) and 19 cancer of the ampulla of Vater (SG: 6; NSG: 13). The rate of R1 resections resulted higher in the SG (66% vs 10%, p < 0.05). The rate of local recurrence did not differ in the two groups (NSG 23.4%, SG 27.6%). No relationships were found between R1 status and development of local recurrence in both groups. Local recurrence occurred in 20% of R1-NSG and in 34.3% of R1-SG. Our study showed that the standardized method determines a significant increase of R1 resection if compared with other non-standardized methods. This difference is due to the different definition of minimum clearance (0-mm- vs 1-mm rule). Even if not significantly, the standardized method seems to better discriminate the patients in terms of local recurrence risk after R1 vs R0 in SG (34 vs 11%) in comparison with R1 vs R0 in NSG (20 vs 27%).