The clinical outcomes of combination chemotherapy in elderly patients with advanced biliary tract cancer: An exploratory subgroup analysis of JCOG1113.

349Background: JCOG1113 is a randomized phase III trial to confirm the non-inferiority of gemcitabine plus S-1 (GS) to gemcitabine plus cisplatin (GC) for advanced biliary tract cancer (BTC) in overall survival (OS). In the final analysis, GS demonstrated non-inferiority to GC in OS and was considered as a new option of standard of care for advanced BTC. However, there are few reports on the efficacy and safety of combination chemotherapy in elderly patients with advanced BTC. Therefore, this study aimed to explore the clinical outcomes of combination chemotherapy in elderly patients with advanced BTC. Methods: Among all enrolled patients in JCOG1113, ≥ 75 years old patients were included in this exploratory subgroup analysis. Cox regression analysis was performed to investigate the influence of age at baseline on OS and PFS. Clinically relevant adverse events (AEs) were defined as any of grade 2 or more fatigue, appetite loss, nausea, vomiting, oral mucositis, and diarrhea, and were compared using Fisher...