Baseline Hemoglobin Predicts Oncologic Outcomes in Intrahepatic Cholangiocarcinoma Treated With Yttrium‐90 Radioembolisation: A Retrospective Cohort Study of 136 Patients

PURPOSE: Tumour oxygenation influences the radiobiological effect of yttrium-90 (Y90); thus, baseline hemoglobin (HGB) may affect treatment response. This study evaluated whether baseline HGB is associated with outcomes in patients with unresectable intrahepatic cholangiocarcinoma (ICC) treated with Y90 transarterial radioembolisation (TARE). METHODS: We retrospectively analysed 136 ICC patients treated with glass microsphere Y90 from 2004 to 2020, stratified by baseline HGB: ≥ 12 g/dL, 10-11.9 g/dL, and < 10 g/dL. Kaplan-Meier and log-rank tests assessed duration of response (DoR), overall survival (OS), and time to progression (TTP). Lesion response was evaluated by RECIST 1.1. Several clinical and radiologic parameters were evaluated in multivariate Cox models to identify independent OS predictors. RESULTS: Mean age was similar across HGB groups (~64 years, p = 0.934), and 49% of the cohort was female. Response rates differed significantly: For RECIST 1.1, responders comprised 38% (15/39) (≥ 12 g/dL), 42% (22/53) (10-11.9 g/dL), and 18% (7/39) (< 10 g/dL) (p = 0.041). Median DoR was longest for HGB ≥ 12 g/dL (15.0 months) vs. 6.5 and 6.2 months for 10-11.9 and < 10 g/dL (p = 0.041). TTP varied significantly (7.1, 5.8, and 1.7 months; p = 0.008). Median OS was 17.1, 13.8, and 6.0 months for ≥ 12, 10-11.9, and < 10 g/dL, respectively (p < 0.001). On multivariate analysis, HGB < 10 g/dL remained independently associated with poorer OS (HR 1.83, p = 0.031). CONCLUSION: Baseline HGB < 10 g/dL was a predictor of poor antitumor response, earlier progression, and worsened OS in ICC patients undergoing Y90 TARE. HGB is a low-cost, clinically available biomarker that may aid in risk stratification and treatment planning. Future work should assess if risk factor modification prior to TARE (i.e., transfusion for HGB < 10) improves clinical outcomes.