Abstract
BACKGROUND: Various studies have reported on the prognostic impact of ductal margin and radial margin status in resected perihilar cholangiocarcinoma (PCCA). No study has considered differences in the prognostic impact of individual resection margins. This study investigated the prognostic impact of individual planes on survival. METHODS: All patients undergoing surgery for PCCA at Amsterdam UMC and Karolinska University Hospital between January 2010 and May 2023 were included. Clinicopathological data were retrospectively retrieved. The primary outcomes were the prognostic significance of residual disease (< 1 mm to the nearest tumour growth) in individual dissection planes and resection margins for overall survival (OS) and disease-free survival (DFS), expressed as adjusted hazard ratios (aHRs). RESULTS: Of 199 patients, 81 (41%) underwent radical resection and 118 (59%) were reported to have microscopic residual disease. Only a positive proximal bile duct resection margin was significantly associated with shorter OS (adjusted median OS 24 versus 36 months; aHR 1.64; 95% confidence interval (c.i.) 1.05 to 2.56; P = 0.031) and DFS (aHR 2.01; 95% c.i. 1.30 to 3.10; P = 0.002). Other positive resection margins and dissection planes did not carry any prognostic information for OS (Pinteraction = 0.95) or DFS (Pinteraction = 0.56). Similar results were obtained in a 90-day landmark sensitivity analysis. CONCLUSION: This study found that only tumour infiltration of the proximal bile duct resection margin was associated with worse prognosis, most likely reflecting the malignant behaviour of the disease rather than surgical failure. Larger prospective studies are needed to clarify the true prognostic impact of residual disease in individual resection planes to allocate patients to specific chemotherapeutic (neo)adjuvant treatments.