ABSTRACT
BACKGROUND & AIMS: Accumulating data has shown the rising incidence and poor prognosis of early-onset gastrointestinal cancers, but few data exist on biliary tract cancers (BTC). We aimed to analyse the clinico-pathological, molecular, therapeutic characteristics and prognosis of patients with early onset BTC (EOBTC, age ≤50 years at diagnosis), versus olders. METHODS: We analysed patients diagnosed with intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and gallbladder adenocarcinoma between 1 January 2003 and 30 June 2021. Baseline characteristics and treatment were described in each group and compared. Progression-free survival, overall survival and disease-free survival were estimated in each group using the Kaplan-Meier method. RESULTS: Overall, 1256 patients were included, 188 (15%) with EOBTC. Patients with EOBTC demonstrated fewer comorbidities (63.5% vs. 84.5%, p < .0001), higher tumour stage (cT3-4: 50.0% vs. 32.3%, p = .0162), bilobar liver involvement (47.8% vs. 32.1%, p = .0002), and metastatic disease (67.6% vs. 57.5%, p = .0097) compared to older. Patients with EOBTC received second-line therapy more frequently (89.5% vs. 81.0% non-EOBTC, p = .0224). For unresectable patients with BTC, median overall survival was 17.0 vs. 16.2 months (p = .0876), and median progression-free survival was 5.8 vs. 6.0 months (p = .8293), in EOBTC vs. older. In advanced stages, fewer actionable alterations were found in EOBTC (e.g., IDH1 mutations [7.8% vs. 16.6%]; FGFR2-fusion [11.7% vs. 8.9%]; p = .029). CONCLUSIONS: Patients with EOBTC have a more advanced disease at diagnosis, are treated more heavily at an advanced stage but show similar survival. A distinctive molecular profile enriched for FGRF2 fusions was found.
