Preliminary report on advanced biliary cancer patients receiving multimodality treatment in the immunotherapy era: a real-world multicentre experience.

Background: Advanced biliary cancer (ABC) is still regarded as an incurable condition. However, the improved depth and duration of response enabled by chemo-immunotherapy may foster intensified strategies, including surgical procedures, radiotherapy and intra-arterial techniques. Objectives: The prevalence, clinical features and treatment outcomes of ABC receiving multimodality treatment in the immunotherapy era are unknown. Design: Newly diagnosed ABC treated with chemo-immunotherapy and loco-regional procedures from February 2022 to December 2024 were retrospectively identified at 10 tertiary referral cancer centres in Italy. Methods: Categorical variables were compared using the chi-squared test, and the inverse probability of treatment weighting analysis was performed to reduce selection biases. Results: Of 241 ABC receiving first-line treatment, 12 (4.9%) fulfilled the inclusion criteria. The median age was 69 (range 36-80), and 9 patients (75%) had intrahepatic cholangiocarcinoma (iCCA). Ten (83.3%) presented with de novo unresectable ABC: 3 (25%) had locally advanced, and 7 (50.3%) had metastatic disease. The median number of metastatic sites was one, with lymph nodes being the most commonly involved location (41.6%, Conclusion: This study, the first on multimodality treatment of ABC in the immunotherapy era, suggests that a highly selected subset of patients may achieve long-term disease control with an intensified approach. Oligometastatic patients and those affected by iCCA appear as the best candidates. Future studies are needed to confirm these preliminary findings.