Epidemiological characterization of biliary tract cancer in a real-world cohort of patients from the Spanish TTD-RETUD gastrointestinal registry

Background Biliary tract cancer (BTC) is a rare disease with limited therapies and bad prognosis. Patients and methods A real-world cohort of patients with BTC from the Spanish RETUD Registry, diagnosed from 2017 to 2025, was analyzed for demographic/clinical characteristics, tumor molecular profile, therapeutic procedures, prognostic factors, and outcomes. Populations were defined as per the first therapy received: surgery/neoadjuvant therapy for the resectable disease (RD) population and first-line therapy for the advanced disease population. Results A total of 1756 patients were included in the study, 695 were RD, of whom 55.9% subsequently experienced tumor recurrence, and 1061 were metastatic at diagnosis. Median age was 68.6 years, and 55.7% were male. The most frequent tumor location was intrahepatic cholangiocarcinoma (53%). Biomarker information was provided for 591 patients, and 42.6% had targetable alterations. Median follow-up time was 14.7 months. In the RD population, surgery was carried out in 95.7% of patients; 5% and 68.9% received neoadjuvant and adjuvant therapies, respectively. Median overall survival (OS) was 33.0 months [95% confidence interval (CI) 30.2-38.9], and median time to relapse was 19.4 months (95% CI 17.3-22.2). In the advanced disease population, immunotherapy was administered to 96.4% and 42.6% of patients in the first- and second-line settings, respectively, whereas targeted therapies were administered to 10.7% and 6.3% of patients, respectively. Median OS was 10.4 months (95% CI 9.7-11.2). Median progression-free survival in patients treated with approved targeted therapies in Spain was 7.1 (95% CI 4.4-NA) versus 4.0 months (95% CI 3.1-5.0), hazard ratio 0.54 (95% CI 0.30-0.99), P = 0.047. Conclusions This study provides valuable data on the clinical characteristics, therapeutic procedures, and evolution of patients with BTC treated in clinical practice in Spain.