Prognostic Impact of Margin Status in Distal Cholangiocarcinoma.

BACKGROUND: A positive ductal margin is strongly associated with poor survival in patients with distal cholangiocarcinoma. However, the significance of the radial margin status and its effect on survival are not fully clarified. METHODS: All patients with distal cholangiocarcinoma who underwent pancreatoduodenectomy between January 2000 and December 2018 at Tokai University Hospital were retrospectively analyzed. Positive margins were divided into positive ductal margin and positive radial margin. RESULTS: One hundred and eight consecutive patients with distal cholangiocarcinoma underwent pancreatoduodenectomy. Margin-negative R0 resection was performed in 85 patients (79%). Twenty-three patients (21%) had a positive resection margin (R1 resection). The 5-year survival rate and median overall survival for patients with R0 resection and those with R1 resection was 64%, 98 months and 25%, 26 months, respectively. There was a significant difference in survival between patients with R0 resection and those with R1 resection (p < 0.001). Patients with positive radial margin (n = 10) had a significantly worse outcome than those with positive ductal margin (n = 13) (p = 0.016). Univariate analysis showed that R1 resection, lymph node metastasis, tumor depth, portal vein invasion, pancreatic invasion, lymphatic invasion, and venous invasion were significant prognostic factors. Multivariate analysis confirmed that R1 resection and nodal involvement were significant independent prognostic indicators after surgical resection for distal cholangiocarcinoma. CONCLUSIONS: Positive surgical margin and nodal involvement were the strongest predictors of poor survival in patients with distal cholangiocarcinoma. Patients with a positive radial margin had a significantly worse outcome than those with a positive ductal margin.