Clinical outcomes and prognostic factors of adjuvant treatment in resectable biliary tract cancer.

Abstract

370 Background: The survival outcomes and prognostic factors of adjuvant treatment after resection for biliary tract cancer (BTC) has not been clearly established. We analyzed the clinical outcomes and prognostic factors of patients with resected BTCs between adjuvant treatment and non-adjuvant treatment group. Methods: A total 189 patients of BTC were treated with surgery followed by adjuvant chemotherapy or concurrent chemoradiotherapy between Jan. 2008 and Jan. 2013. We retrospectively analyzed the clinical characteristics and recurrence and survival outcomes with following variables: histologic grade, resected margin status, lymphatic/vascular/perineural invasion, T and N stage, treatment modality. Results: Median age at diagnosis was 64 years (range: 32-85). Of the total 189 patients, R0 resection was done in 152 patients (80.4%). Among the 73 patients with adjuvant treatment, forty-one patients (21.6%) were treated with adjuvant 5-FU based systemic chemotherapy and 31 patients with chemoradiotherapy (16.5%). Recurrence rate were 39.7%. Median disease free survival (DFS) time was 58.1 months (95% CI, 38.9-77.3) and median overall survival (OS) time was 87.8 months (95% CI, 79.5-96.0). Adjuvant treatment showed the tendency to improve DFS with 39.0 months (95% CI, 8.9-69.1) in the adjuvant group compared with 57.0 months (95% CI, 39.5-74.5) in the non-adjuvant group, however, without statistical significance (p=0.113). Between the recurrent and non-recurrent group, perineural invasion, lymphatic invasion and poorly differentiated histology showed statistical significant difference, respectively (65.3% vs 35% ; p <.001, 28% vs 14.9% ; p = .028, and 8.1% vs 7.1% ; p = .011). Presence of perineural invasion showed association with RFS (HR= 1.543; 95% CI 1.133-2.102, p=.006). There was no other significant correlation in R1 resection, poor histologic grade, lymphatic and vascular invasion, chemotherapy regimen, and treatment modality with survival outcome. Conclusions: Perineural invasion could be a potential prognostic factor for recurrence. Further prospective study should be warranted to confirm this data.