Prognostic comparison of the longitudinal margin status in distal bile duct cancer: R0 on first bile duct resection versus R0 after additional resection

Background This study investigated survival differences following intra-operative frozen-section examination of bile duct resection margins and final longitudinal margin status (LMS) in distal bile duct cancer (BDC). Methods One hundred and ninety-three patients underwent Whipple's operation for curative resection of distal BDC from 2008 to 2016. Patients were sorted into two and three groups according to LMS of the frozen-sections and the final pathological specimen results: R0 on first bile duct resection (primary R0), R0 after additional resection (secondary R0), and no evidence of residual carcinoma (FR0), carcinoma in situ or high-grade dysplasia (FR1-CIS/HGD), or invasive carcinoma (FR1-INV). Survival and prognostic factors according to LMS were analyzed. Results The final R0 ratio increased from 82.3% to 90.1% through additional resection. The 5-year overall survival (OS) of primary and secondary R0 were 60.8%, 46.1% (P = 0.969). And disease-free survival of primary and secondary R0 were 54.6%, 54.9% (P = 0.903). The 5-year OS after FR0, FR1-CIS/HGD, FR1-INV were 59.3%, 59.5%, 14.3% (P = 0.842). LMS of the bile duct was an independent prognostic factor by multivariable analyses. Conclusions If R0 of final LMS was achieved, it would help to improve survival regardless of R0 through additional resection. And, it should be avoided remaining invasive cancer at the longitudinal margin whenever possible.