PCN322 TREATMENT OF ADVANCED BILIARY TRACT CANCER (BTC) AFTER PROGRESSION ON FIRST-LINE (1L) SYSTEMIC THERAPY

Abstract

In the absence of clear recommendations for the treatment of BTC after progression on 1L therapy, information on second-line (2L) treatment in the real-world setting is sparse. This study describes 2L treatment patterns for advanced BTC in an older US population. We identified patients with BTC aged ≥66 years using the Surveillance, Epidemiology, and End. Results cancer registry data linked with Medicare claims. We included patients with advanced, microscopically confirmed BTC who had gallbladder, intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, or ampulla of Vater cancer between 2010 and 2013. Chemotherapy use over time was described using Medicare claims; lines were inferred from changes and gaps in therapy. Patients receiving ≥1 line of treatment were followed from initial diagnosis to end of follow-up, second primary cancer, or switch to managed care. 1461 patients with advanced BTC were identified, of whom 38% had gallbladder, 26% had intrahepatic, 22% had extrahepatic, and 8% had ampulla of Vater cancer. Median age at diagnosis was 77 years, with a median follow-up of 8.5 months (88% died). 558 patients (38%) received 1L therapy. Of these, 39% (n=220) received 2L treatment. Median time from diagnosis to start of 2L was 34 weeks (95% CI, 23–49). Median time from end of 1L to start of 2L was 49 days (95% CI, 21–90). There was wide variability in 2L treatments, including 25 unique treatment combinations. Some combination of fluorouracil (including capecitabine), gemcitabine, or platinum therapy was used. Most patients received monotherapy (n=107 [49%]), with 31% (n=68) receiving a doublet. Variations in 2L regimens in this older population reflects the lack of consensus on how to treat older patients with advanced BTC whose 1L treatment failed. These findings highlight the unmet medical need in 2L BTC, an indication in need of effective new agents.