The Status of Liver Margin in Perihilar Cholangiocarcinoma: A Multicenter Study.

Abstract

To investigate the prevalence and distribution of carcinoma in the liver margin (LM) of resected perihilar cholangiocarcinoma (pCCA) and establish a method for LM examination. LM is the largest margin in resected pCCA with undefined status and assessment method. Two hundred twenty-seven pCCA cases who underwent major hepatectomy were divided into a discovery cohort (n = 101) assessed using serial whole-mount digital large sections (WDLS) combined with small sections, and a control cohort (n = 126) assessed using only small sections. The LM R1 resection rate was 38.6% (39/101) in the discovery cohort and 5.6% (7/126) in the control cohort. WDLS identified more LM R1 cases compared with the small section in the discovery cohort (38.6% vs 5.9%, P < 0.001). R0 patients in the discovery cohort had better overall survival and recurrence-free survival than those in the control cohort (both P < 0.05). In addition, 95% of carcinoma was found within 20 mm of the proximal ductal margin (P-DM). A P-DM distance of <5 mm was an independent risk factor for LM R1 resection. Patients with this are more likely to experience R1 compared with those with ≥ 5 mm ( P < 0.001). Positive LM was the significant cause for R1 resection of pCCA and the utilization of WDLS improved the diagnostic accuracy of LM. An examination methodology was established, highlighting the necessity of examining LM within a 20 mm radius around the P-DM, especially in patients with a P-DM of <5 mm.