The aim of this study is to evaluate the prognostic impact of an
intraductal carcinoma component and bile duct
resection margin status in patients with biliary tract
carcinoma. An
intraductal carcinoma component was defined as
carcinoma within the bile duct outside the main
tumor nodule consisting of a subepithelial invasive component. Surgically resected materials from 214 patients were evaluated by histological observations. Seventy-nine patients (36.9%) with an
intraductal carcinoma component infrequently developed large
tumors and infrequently showed deep invasion and venous, lymphatic and perineural involvement in the main
tumor nodule. An
intraductal carcinoma component was inversely correlated with advanced clinical stage, and was shown to be a significantly favorable prognostic factor by both univariate and multivariate analyses. Proximal (hepatic) side bile duct
resection margin status was categorized into negative for
tumor cells, positive with only an
intraductal carcinoma component [R1 (is)], and positive with a subepithelial invasive component (R1). Forty-five patients (21.0%) with an R1
resection margin had a poorer prognosis than 148 patients (69.2%) with a negative
resection margin, whereas 21 patients (9.8%) with an R1 (is)
resection margin did not. In patients with an R1
resection margin, the risk of anastomotic recurrence was higher, and the period until anastomotic recurrence was shorter, than in patients with an R1 (is)
resection margin. Surgeons should not be persistent in trying to achieve a
negative surgical margin when the intraoperative frozen section diagnosis is R1 (is), and can choose a safe
surgical procedure to avoid postoperative complications.