Comparison of clinical features by primary sites in patients with biliary tract cancer who received gemcitabine-based chemotherapy: An exploratory analysis of JCOG1113.

Abstract

548 Background: Biliary tract cancers (BTCs) include gallbladder cancer (GBC), intrahepatic cholangiocarcinoma (IHCC), extrahepatic cholangiocarcinoma (EHCC), and ampulla of Vater cancer (AV). Although it was previously reported that there were differences in clinical features individually, the reported data were limited to data from some subgroup analyses of recent randomized controlled trials. JCOG1113 (UMIN000010667) showed the non-inferiority of gemcitabine plus S-1 to gemcitabine plus cisplatin in terms of overall survival (OS) in patients (pts) with advanced BTCs. We aimed to compare clinical features among the primary sites of BTCs using JCOG1113 data. Methods: Among the 354 pts enrolled in JCOG1113, 352 pts were included in this analysis except for 2 pts without BTCs. We compared the patient characteristics and treatment outcomes, such as OS, progression-free survival (PFS), and objective response rate (ORR), among the four primary sites. Results: Of the 352 pts, 137 pts (38.9%), 94 pts (26.7%), 108 pts (30.7%) and 13 pts (3.7%) had GBC, IHCC, EHCC, and AV, respectively. GBC was more common in females (58.4%) than males, in contrast to the other primary sites. The percentage of pts with metastatic disease for GBC was the highest (78.1%) and involved multiple metastatic organs (41.6%), in contrast with the other primary sites. The median OS for GBC, IHCC, EHCC and AV were 12.6 months (reference), 15.7 months (hazard ratio [HR]; 0.749, 95% confidence interval [CI], 0.559-1.005), 16.3 months (0.704, 0.532-0.934) and 11.5 months (1.148, 0.633-2.080), respectively. The median PFS for GBC, IHCC, EHCC and AV were 5.7 months (reference), 6.2 months (0.843, 0.644-1.104), 8.7 months (0.636, 0.489-0.826) and 4.1 months (1.506, 0.851-2.665), respectively. The ORRs for GBC, IHCC, EHCC and AV were 34.4%, 28.9%, 34.4%, and 0.0%, respectively. Conclusions: Except for AV which included a few patients in this trial, GBC showed a poorer prognosis compared with the other primary sites. Furthermore, it was more likely to include metastatic disease and multiple metastases, and this is likely one of the causes of the poorer prognosis. [Table: see text]