Second-line Chemotherapy Prolongs Survival in Real World Patients With Advanced Biliary Tract and Gallbladder Cancers A Multicenter Retrospective Population-based Cohort Study

Background: Limited evidence is available regarding the survival benefit of second-line therapy in real world patients with advanced biliary tract and gallbladder cancer. Until very recently, there was a lack of randomized clinical trials to address this important question. In this multicenter population-based cohort study, the authors evaluated whether second-line therapy improves the survival of real world patients with advanced biliary tract and gallbladder cancer. Methods: Patients with biopsy-proven advanced biliary tract and gallbladder cancer who were diagnosed during the period of 2006 to 2015 and had received first-line chemotherapy were assessed. Cox proportional multivariate analysis was performed to determine the survival benefit of second-line therapy. Results: One hundred thirty-six eligible patients with a median age of 66 years and male:female ratio of 1:1.34 were identified. Sixty-eight percent of patients had metastatic disease. Primary tumor sites were as follows: gallbladder 31%, intrahepatic cholangiocarcinoma 36%, extrahepatic bile duct 23%, and ampullary cancer 10%. Overall, 37% of patients received second-line therapy. The median overall survival of the treatment group was 17 months (95% confidence interval [CI]: 12.5-21.5) compared with 7 months (95% CI: 5.3-8.7) in the control (P<0.0001). Patients who received combination chemotherapy had a median overall survival of 20 months (14.0-26.1) compared with 17 months (13.5-20.5) if they received single-agent second-line therapy (P=0.73). Multivariate analysis of second-line therapy, hazard ratio: 0.55 (95% CI: 0.36-0.83) and neutrophil to lymphocyte ratio >2, HR: 1.10 (1.05-1.15) showed a significant correlation with survival. Conclusions: This well-designed population-based retrospective cohort study suggests that second-line chemotherapy improves survival of real world patients with advanced biliary tract and gallbladder cancers and should be offered to the patients who are potential candidates for chemotherapy.