Objectives: The objective of this study was to determine whether carcinoma in situ at the bile duct margin is prognostically different from residual invasive carcinoma in patients with extrahepatic cholangiocarcinoma. Although there are many reports that the ductal margin status at bile duct resection stumps is a prognostic indicator in patients with extrahepatic cholangiocarcinoma, some patients who undergo resection with microscopic tumor involvement of the bile duct margin survive longer than expected.
Methods: A retrospective clinicopathological analysis of 128 patients who had undergone surgical resection for extrahepatic cholangiocarcinoma was conducted. The status of the bile duct resection margin was classified as negative in 105 patients (82.0%), positive for carcinoma in situ in 12 patients (9.4%), and positive for invasive carcinoma in 11 patients (8.6%).
Results: Ductal margin status was an independent prognostic indicator by both univariate (p = 0.0022) and multivariate (p = 0.0105) analyses, along with lymph node metastasis. There was no significant difference between patients with a negative ductal margin and those with a positive ductal margin with carcinoma in situ (p = 0.5247). The 5-year survival rate of patients with a positive ductal margin with carcinoma in situ (22.2%) was significantly better (p = 0.0241) than with invasive carcinoma (0%). There was a significant relationship between local recurrence and ductal margin status (p = 0.0401).
Conclusions: Among patients undergoing surgical resection for extrahepatic cholangiocarcinoma, invasive carcinoma at the ductal resection margins appears to have a significant relation to local recurrence and also a significant negative impact on survival, whereas residual carcinoma in situ does not. Discrimination whether carcinoma in situ or invasive carcinoma is present is important in clinical setting in which the resection margin at the ductal stump is positive.