Patterns of progression and efficacy of immune checkpoint inhibitors in unresectable, recurrent, or metastatic cholangiocarcinoma: A real-world study

AIMS: To characterize the progression patterns and analyze the efficacy of immune checkpoint inhibitors (ICIs) in unresectable, recurrent, or metastatic cholangiocarcinoma (CCA). METHODS: A retrospective analysis was conducted in CCA patients treated with ICIs between September 2019 and September 2024. The progression patterns of ICIs were assessed, and survival and prognostic factors were analyzed using Kaplan-Meier and Cox regression models. RESULTS: Among 131 eligible patients, the median overall survival (OS) and progression-free survival (PFS) were 14.1 and 7.9 months, respectively. Multivariable Cox analysis identified lung metastasis, absent abdominal lymph node/retroperitoneal lymph node (LN/RPLN) metastasis, and CA199 ≥ 35 U/ml as independent predictors of shorter PFS, and smoking, no surgery, and CA199 ≥ 35 U/ml as predictors of shorter OS (all p < 0.05). Rising CA199 correlated with poorer PFS (p < 0.05). Progression occurred in 80 patients, 77.5% within 12 months. Oligo-progression was the main pattern (53.8%). Liver (43.8%) and abdominal LN/RPLN (38.8%) were the most common sites of progression. Oligo-progression was associated with superior OS versus systemic progression (median 22.7 vs. 11.7 months, p = 0.003). Among oligo-progression patients, local plus systemic therapy showed a trend toward better OS than systemic therapy alone (28.9 vs. 15.8 months, p = 0.062). CONCLUSIONS: ICIs demonstrate meaningful efficacy in CCA. Oligo-progression represents the predominant failure pattern and is associated with favorable prognosis.