Real-world survival of patients (pts) with colorectal adenocarcinoma liver metastases (CRLM) treated with transarterial radioembolization (TARE).

40 Background: While TARE with yttrium-90 (Y90) microspheres can induce tumor responses and improve progression-free survival (PFS) in pts with CRLM, randomized trials have not shown an overall survival (OS) benefit. It is unclear whether this is due to suboptimal pt selection and/or trial design vs. possibly a radiation-induced delayed liver damage which compromises OS. The objective was to describe real world OS with TARE for pts evaluated at an academic center (University of California Irvine) with a dedicated multidisciplinary liver tumor board (MTB). Methods: Retrospective study of consecutive pts with CRLM undergoing TARE between 01/2016-07/2020. We performed descriptive analyses for relevant pt and tumor characteristics, Wilcoxon Signed-Rank Test for comparison of continuous variables, and Kaplan-Meier estimates for survival. Results: N=55 pts were included. Follow-up time was at least 24 mo. Median age was 60 yrs (range 36-84), 61.8% were female, Caucasian/Hispanic/Asian/Other= 54.4%/16.4%16.4%/12.7%, ECOG 0/1/2= 32.7%/58.2%/9.1%, tumor sidedness: left/right/unknown 72.7%/23.6%/3.6%, number or prior lines of systemic treatment 1/2/3+= 38.2%/26.4%/21.8%. MSI-High= 3.6% and RAS/RAF mutations were present/absent/unknown in 34.5%/49.1%/16.4%. Baseline and post-TARE liver function tests are shown in the table. Median time from diagnosis to first TARE was 16.4 mo (1.7-95.6) and 36.4% were treated within the first 12 mo of diagnosis. Median OS from diagnosis and first TARE were 43.2 mo (29.5-68.7) and 16.7 mo (9.9-35.2), respectively. Conclusions: The observed OS of pts with CRLM treated with TARE with a mature follow-up of at least 2 years exceeds 40 mo, despite early integration of TARE in a third of the pts within the first 12 mo of diagnosis. Evaluation of pts with CRLM for TARE at experienced centers with dedicated MTB might lead to improved outcomes. [Table: see text]