Impact of intrapancreatic or extrapancreatic bile duct involvement on survival following pancreatoduodenectomy for common bile duct cancer

Background: The clinicopathological factors that influence survival following pancreatoduodenectomy (PD) for common bile duct (CBD) cancer are not well known. This study aimed to investigate the effect of tumour involvement of the intrapancreatic versus extrapancreatic CBD on margin status, overall (OS) and disease-free (DFS) survival. Methods: This was a retrospective study of patients who underwent PD for CBD cancer between 2001 and 2009. Pathological examination was performed according to a previously described standardized protocol based on axial slicing. Clinicopathological data and outcome in terms of margin status, DFS and OS were compared between cancers involving exclusively the intrapancreatic CBD (CBDin) and those involving the extrapancreatic CBD, in isolation or combined with invasion of the intrapancreatic part of the duct (CBDex). Results: A total of 66 patients were enrolled. Most CBD cancers were locally advanced (97 per cent pathological (p) T3, 76 per cent pN1). Microscopic margin involvement (R1) was more frequent in CBDex than in CBDin cancers (34 of 39 versus 13 of 27; P = 0.001), more often multifocal (P < 0.001) and more frequently affected the periductal margin (P = 0.005). Venous resection was more often required for CBDex cancers (P = 0.009). CBDex cancers were associated with worse OS (median 21 versus 28 months; P = 0.020) and DFS (14 versus 31 months; P = 0.015), but the rate and site of recurrence did not differ. Metastasis to more than two lymph nodes was an independent predictor of OS and DFS. Conclusion: CBDex cancer is associated with a higher rate of R1 resection and venous resection after PD, and has a worse outcome than CBDin cancer.