Objective: The aim of the study was to evaluate whether carcinoma in situ (CIS) residue at the ductal stump affects the survival of patients undergoing resection for extrahepatic cholangiocarcinoma.
Background: Positive ductal margin with CIS has been treated as a tumor-free margin from a prognostic viewpoint because several studies have reported that residual CIS foci at the ductal stump do not affect survival after resection.
Methods: Patients who underwent resection for extrahepatic cholangiocarcinoma were retrospectively reviewed. The surgical margin status was histologically divided into negative (R0), positive with CIS (R1cis), and positive with invasive cancer (R1inv). The survival and incidence of local recurrence were compared among the groups.
Results: Of 684 consecutive resected patients, 172 patients with early-stage (pTis-2N0M0) cholangiocarcinoma (perihilar, n = 144; distal, n = 28) were analyzed. The cumulative incidence of local recurrence in R1cis patients was higher than R0 patients (32.8% vs 4.4% at 5 years, P < 0.001) and lower than R1inv patients (50.0% at 2 years, P = 0.012). The disease-specific survival for R1cis patients was worse than for R0 patients (35.1% vs 78.7% at 5 years, P = 0.005) and better than for R1inv patients (40.0% at 2 years, P = 0.002). The uni- and multivariate analyses identified the surgical margin status as an independent prognostic factor (R1cis vs R0, relative risk 2.39, P = 0.026; R1inv vs R0, RR 10.28, P < 0.001).
Conclusion: R1cis increases the incidence of local recurrence and shortens postoperative survival in patients with early-stage cholangiocarcinoma, although this prognostic effect was less severe compared with R1inv. R1cis should be avoided as much as possible in surgery for early-stage cancer, although it may be allowed in advanced tumors.