Role of Adjuvant Chemoradiotherapy in Perihilar Bile Duct Cancer: A Single Institutional Long-Term Follow Up Analysis

Abstract

The role and indication of adjuvant therapy in perihilar cholangiocarcinoma remains to be elucidated. The aim of this analysis was to identify the effects of concurrent chemoradiotherapy (CCRT) and define the clearance cut-off of various margins in perihilar cholangiocarcinoma.A retrospective analysis was performed on 290 patients who received definitive resection from January 2000 through December 2015. The exclusion criteria were as follows: (a) palliative resection (n = 91), (b) multiple primary cancer diagnosis within 5 years (n = 30), (c) adjuvant therapy at outside institution (n = 19). Treatment result analysis for various end-points including overall survival (OS), disease-free survival (DFS), locoregional-recurrence free survival (LRRFS), and distant-metastasis free survival (DMFS) was performed using the Kaplan-Meier method.Among 150 patients of analyzed cohort, adjuvant therapy was performed in 112 (74.7%) patients: chemotherapy alone (n = 6), radiotherapy (n = 6), and CCRT (n = 100). Number of patients with nodal and margin involvement were 45 (31.9%) and 58 (38.7%), respectively. Median follow-up duration was 24.3 months. In univariate analysis, nodal involvement (HR = 1.7, 95% CI: 1.1-2.4, P = 0.009), lymphatic invasion (HR = 1.6, 95% CI: 1.1-2.3, P = 0.011) were adverse prognostic factors for OS. In multivariate analysis, margin involvement (HR = 1.8, 95% CI: 1.1-2.8, P = 0.019) was an adverse prognostic factor for OS. CCRT was associated with better overall survival (HR = 0.5, 95% CI: 0.3-0.9, P = 0.012). On subgroup analysis for patients with nodal and/or margin involvement, survival gain was found with use of CCRT in both OS and LRRFS (P = 0.02 and P = 0.02, respectively). Not only margin involvement but, close resection margin was related with poor treatment results. Clearance cut-off for vascular and radial resection margin was 0.1cm and 0.2cm, respectively (P = 0.0192).Negative surgical margins and CCRT as adjuvant treatment were statistically significant prognostic factors. Treatment result was improved with CCRT for patients with margin and/or nodal involvement. Suggested clearance for vascular and radial margin from current analysis was 0.1cm and 0.2cm, respectively.