Redefining the R1 resection in pancreatic cancer

BACKGROUND: Resection margin (RM) status in pancreatic head adenocarcinoma is assessed histologically, but pathological examination is not standardized. The aim of this study was to assess the influence of standardized pathological examination on the reporting of RM status. METHODS: A standardized protocol (SP) for pancreaticoduodenectomy specimen examination, involving multicolour margin staining, axial slicing and extensive tissue sampling, was developed. R1 resection was defined as tumour within 1 mm of the RM. A prospective series reported according to this protocol (SP series, n = 54) was compared with a historical matched series in which a non-standardized protocol was used (NSP series, n = 48). RESULTS: Implementation of the SP resulted in a higher R1 rate overall, and for pancreatic (22 of 26 85 per cent) compared with ampullary (four of 15) and bile duct (six of 13) cancer. Sampling of the circumferential RM was more extensive in the SP series and correlated with RM status. RM involvement was often multifocal (14 of 32), affecting the posterior RM most frequently (21 of 32). Survival correlated with RM status for the entire SP series (P < 0.001), but not for the NSP series. There was a trend towards better median and actuarial 5-year survival after R0 resection in the SP pancreatic cancer subgroup. CONCLUSION: Standardized examination influences the reporting of RM status.