SP 9.04 Redefining Resection Margins in Pancreatic Cancer: A Comprehensive Systematic Review and Meta-Analysis of Margin Width and Survival After Pancreaticoduodenectomy
Mehrdad Mozafar, Yasamin Bigdeli, Ahmad Madankan, Kimia Jazi, Mohamad Mozafar, Farid Froghi, Ali YousafAbstract
Background
Surgical margin status critically influences survival after Pancreaticoduodenectomy (PD), yet inconsistencies in margin definitions have produced conflicting results. This systematic review and meta-analysis evaluates the impact of margin thresholds for R0 and R1 on overall (OS) and disease-free survival (DFS).
Methods
Eligible studies included adults undergoing PD with defined microscopic margin thresholds (0 mm, 1 mm, 1.5 mm, or 2 mm) and reporting OS and/or DFS as probabilities or hazard ratios (HR). Subgroup and meta-regression analyses evaluated factors including lymphovascular and perineural invasion, margin width and site, and treatment approach (upfront vs. neoadjuvant).
Results
Across 18 studies including over 5170 patients, R1 resections were associated with a 40% higher risk of death and a 43% greater risk of recurrence or mortality compared with R0 resections. Regarding HR based on margin widths, OS decreased significantly by 72% at 0 mm, 30% at 1 mm, and 44% at 1.5 mm, but 28% non-significantly at 2 mm. In line with HR results, pooled survival probabilities confirmed that margin clearance up to 1.5 mm consistently predicted superior outcomes, with no additional survival benefit beyond this threshold. Retroperitoneal margin showed the poorest outcomes across margin definitions. Neoadjuvant therapy did not fully mitigate the adverse impact of R1 resections, while upfront surgery was associated with poorer survival across all margin widths.
Conclusion
Achieving a negative margin of at least 1.5 mm provides the greatest survival advantage, beyond which further clearance offers minimal benefit. Margin positivity at the retroperitoneum is linked to the worst outcomes.