Survival by line of therapy of older patients with advanced biliary tract cancer (BTC).

Abstract

497 Background: Overall survival (OS) in advanced or metastatic BTC has not been adequately described outside the clinical trial setting. Further, real-world descriptions of OS by line of therapy, including in patients who do not receive systemic chemotherapy, are not widely available. In this study, we used data from a recent cohort of US patients available in the SEER-Medicare linked database to examine OS from diagnosis of advanced or metastatic BTC as well as from initiation of first- and second-line treatment. Methods: Patients with advanced or metastatic BTC diagnosed between 2010 and 2013 were identified in SEER-Medicare, with follow-up through 2014. Demographic and clinical characteristics were analyzed. The Kaplan-Meier estimator was used to describe OS from diagnosis among all patients, OS from diagnosis among patients who did not receive systemic treatment, and OS by line of treatment, from date of treatment initiation. The Cox proportional hazards model was used to identify demographic and clinical factors associated with survival. Results: Of the 1,461 eligible patients aged ≥66 years, 39% had gallbladder, 22% had intrahepatic, 22% had extrahepatic, and 9% had ampulla of Vater cancer. More than two-thirds of patients had stage IV disease, and 38% of patients (n = 558) received systemic chemotherapy. Systemic treatment patients were somewhat younger, more likely to be white, have stage IV cancer and less likely to have mobility limitations (24% vs. 38%) than patients who did not receive systemic treatment. Among all patients, unadjusted median OS from diagnosis was 5.6 months (95% CI 5.0-6.1). Among patients who were not treated, unadjusted median survival was 3.3 months (n = 903; 95% CI 2.8-4.0) from diagnosis. When OS was evaluated by line of treatment, median OS was 8.2 months (n = 558; 95% CI 7.6-9.0) from first-line initiation and 5.6 months (n = 220; 95% CI 4.6-6.5) from second-line initiation. Conclusions: Among newly diagnosed, older US patients, less than half receive systemic treatment for their advanced BTC, and outcomes among both treated and untreated patients remain poor. There is an immediate need for better therapies to treat patients with advanced BTC.