Optimal Indications for Additional Resection of the Invasive Cancer-Positive Proximal Bile Duct Margin in Cases of Advanced Perihilar Cholangiocarcinoma

The survival benefits of additional resection of the positive proximal ductal margin in cases of perihilar cholangiocarcinoma remain to be elucidated. The purpose of this retrospective study was to clarify the optimal indications for additional resection of the invasive cancer-positive proximal ductal margin (PM) All patients who underwent hepatectomy for perihilar cholangiocarcinoma between 2000 and 2011 were analyzed. Surgical variables, the status of the PM, prognostic factors, and survival were evaluated. A total of 224 patients were enrolled. Additional resection was performed in 52 of 75 positive PMs of invasive cancer, resulting in 43 negative PMs. The survival of patients with a negative PM treated with additional resection (n = 43) was significantly worse than that of the patients with a negative PM treated without additional resection (n = 149; P = 0.031) and did not significantly differ from that of the patients with a positive PM (n = 32; P = 0.215). A multivariate analysis demonstrated that the carbohydrate antigen 19-9 (CA19-9) level (< 64 or a parts per thousand yen64), combined vascular resection, pN, pM, the histological grade, perineural invasion, liver invasion, and R status were independent prognostic factors. Only in the subgroups of CA19-9 < 64 and pM0, the survival of the patients with a negative PM treated with additional resection was significantly better than that of the patients with a positive PM (P = 0.019 and P = 0.021, respectively). Additional resection of the invasive cancer-positive PMs may be warranted only in limited patients with a lower level of CA19-9 and no distant metastatic disease.