Abstract
Background and Aims: Evidence regarding the survival benefit of endobiliary radiofrequency ablation (RFA) in perihilar cholangiocarcinoma (CCA) remains limited. We evaluated the association between endobiliary RFA and overall survival in unresectable perihilar CCA, with a focus on the timing of exposure.
Methods: This retrospective cohort study included 475 patients with unresectable perihilar CCA treated with endoscopic biliary drainage between 2015 and 2025 (90 with a single RFA session, 50 with two or more). RFA was modeled as a time-dependent cumulative count (0, 1, or ≥2 sessions), with landmark analyses of subsequent 6-month mortality at baseline and 3, 6, 9, and 12 months. Sensitivity analyses adjusted for stent type and calendar year.
Results: RFA within 7 days of drainage was associated with lower 6-month mortality (adjusted hazard ratio [aHR], 0.34; 95% CI, 0.16–0.70; P=0.004). At the 3-month landmark, two or more sessions were associated with lower mortality (aHR, 0.10; P=0.024); no association was seen at later landmarks. These estimates were unchanged after adjustment for stent type and calendar year. Over the entire follow-up, two or more sessions were associated with lower mortality (aHR, 0.59; P=0.007), but this association was attenuated after adjustment for calendar year (aHR, 0.77; P=0.209). Recurrent biliary obstruction was more frequent after RFA (37.9% vs. 22.1%; P<0.001), with the excess confined to non-tumor causes.
Conclusions: Endobiliary RFA was associated with improved survival in unresectable perihilar CCA, with the benefit concentrated in the first three months after biliary drainage, at the cost of more frequent non-tumor biliary obstruction.