Chemoimmunotherapy in advanced biliary tract cancers: A meta-analysis of clinical outcomes.

e16257 Background: Biliary tract cancers (BTCs)—encompassing tumors of the bile ducts, gallbladder, or ampulla of Vater—are notoriously hard to manage, especially when surgery is off the table. Standard chemotherapy provides only modest benefits, and while emerging treatments such as immune checkpoint inhibitors and targeted drugs have shown promise, mixed clinical trial results and varied study endpoints have left their true impact unclear. This concise review consolidates current evidence on combining chemotherapy with immunotherapy, with or without targeted agents, to clarify whether these regimens can significantly improve outcomes and steer more effective treatment strategies for BTCs. Methods: A meta-analysis was conducted using data from randomized controlled trials (RCTs) and prospective comparative studies published between 2010 and 2024 in PubMed, Embase, Web of Science, and ClinicalTrials.gov. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were calculated using the inverse variance method, with tau² estimated through the DerSimonian-Laird method. Median survival times (MST) were used to approximate HRs, and confidence intervals were calculated using event numbers (deaths or progression). Heterogeneity across studies was assessed with the I² statistic. Results: Five trials, including 1,241 patients with advanced BTCs, were analyzed. Chemoimmunotherapy demonstrated significant survival benefits, reducing the risk of death (HR for OS: 0.83, 95% CI: 0.75–0.93) and progression (HR for PFS: 0.80, 95% CI: 0.73–0.89). The pooled ORR was 44% (95% CI: 0.31–0.58), and the DCR was 89% (95% CI: 0.78–0.97), indicating robust tumor control. Conclusions: This meta-analysis highlights chemoimmunotherapy as a significant advancement for advanced biliary tract cancers, offering improved survival and robust tumor control. While associated with increased toxicity, adverse events were generally manageable. These findings support the integration of chemoimmunotherapy into standard of care and emphasize the need for future research to optimize patient selection and refine treatment strategies.