726PNATURAL HISTORY OF UNTREATED PATIENTS WHO HAD METASTATIC BILIARY TRACT CANCER (BTC) WITH GOOD PERFORMANCE STATUS (PS)

ABSTRACT Aim: Although chemotherapy is widely recommended for patients with metastatic biliary tract cancer (BTC), the natural course of these patients, especially those with good performance status (PS) who are indicated for chemotherapy, is not known. Methods: We retrospectively reviewed patients with metastatic or locally advanced BTC who were examined between January 2005 and September 2013 at six cancer centers. Patients were eligible if they had good PS (Eastern Cooperative Oncology Group score 0-2) and no history of any treatment for cancer. The primary objective was to evaluate the survival time of patients with advanced BTC with good PS who were untreated. Results: Of the 1,677 screened patients, 204 met the inclusion criteria. The median age was 70.1 years and median overall survival (OS) was 7.1 months. OS by disease location was 4.7 months for intrahepatic, 9.7 months for extrahepatic, 4.4 months for gallbladder, and 11.2 months for ampulla of Vater cancer. In subgroup analysis, OS of locally advanced BTC was 13.8 months and that of patients with normal CEA/CA 19-9 was 10.6 months. In multivariate analysis, variables that were associated with poor prognosis were disease extent (metastatic disease) [HR 2.19 (95% CI 1.39-3.45 p = 0.001)], high baseline CEA level (defined as > 4.0 ng/mL) [HR 1.51 (95% CI 1.06-2.17 p = 0.024)], and high baseline CA 19-9 level (defined as > 100 U/mL) [HR 1.93 (95% CI 1.33-2.91 p = 0.001)]. Conclusions: Metastatic BTC with good PS showed modest survival without any treatment for primary cancer. Furthermore, subgroup analysis showed that patients with normal CA19-9 or CEA level or locally advanced status had favorable survival. Further studies comparing the outcome of chemotherapy with that of best supportive care in patients with unresectable BTC are warranted. Disclosure: All authors have declared no conflicts of interest.