Introduction : The staging system for distal cholangiocarcinoma was changed in AJCC 8th edition. The aim of this study was to investigate the prognostic factors for survival of distal cholangiocarcinoma after curative resection, and to evaluate the impact of metastatic lymph node count for survival, revised in AJCC cancer staging 8th edition.

Methods : All patients who underwent pancreaticoduodenectomy or bile duct resection with curative intent for distal cholangiocarcinoma between 2004 and 2017 at Chonnam National University Hwasun Hospital were reviewed retrospectively. Survival outcome was evaluated using Kaplan-Meier method, and the Cox proportional hazards model was used for multivariable analysis.

Results : 248 patients were included. Overall survival rates for 1, 3, and 5 years were 81.4%, 49.5%, and 34.9% respectively. Median survival time was 35.0 months. In univariate analysis, the prognostic factors influencing survival were elevated serum total bilirubin(≥5mg/dL), infiltrative appearance, histologic differentiation, T-stage, lymph node involvement, new N-stage of AJCC 8th edition, TNM stage of AJCC 7th edition, perineural invasion, lymphovascular invasion, and margin involvement. Among them, histologic differentiation, N-stage of AJCC 8th edition, and margin status were identified to be independent prognostic factors in multivariate analysis.

Conclusions : Histologic differentiation, new N-stage of AJCC 8th edition, and margin status were the independent prognostic factors. The new N-stage of AJCC 8th edition was superior to predict the prognosis after curative resection for distal cholangiocarcinoma, compared to AJCC staging system of 7th edition.