The existence of biliary intraepithelial neoplasia at resection margin is not a risk factor for recurrence of biliary tract cancer

Invasive carcinoma or dysplasia (biliary intraepithelial neoplasia [BilIN]) is often found in the surgical stumps of biliary tract cancer. We investigated whether the presence of BilIN at the surgical margin is a risk factor for recurrence. Seventy-five consecutive patients who underwent curative resection for biliary tract cancer were included in this study. We retrospectively evaluated the surgical margin status (negative, BilIN, or positive) and analyzed the postoperative disease recurrence rate and recurrence pattern by the status. The disease-free survival rate was significantly worse in the positive margin group than in the negative margin group (11 vs 18 months, p = 0.027). There were no statistical differences between the BilIN-positive group and the other two groups. In the multivariate analysis, infiltrative growth (INF) c (HR 3.348, 95%CI 1.368-8.195, p = 0.008) and pathological exhumed margin (pEM) (HR 2.670, 95%CI 1.097-6.495, p = 0.030) were independent recurrence factors. The margin status of BilIN was not associated with recurrence (HR 0.867, 95%CI 0.491-2.946, p = 0.687). The BilIN component at the surgical margin was not associated with short-term recurrence, but the pEM-positive and INFc were. INFc may be a potential predictive factor for recurrence.