Hepatic Artery Infusion Chemotherapy Compared to Transarterial Radioembolization For Unresectable Colorectal Liver Metastases.

This study evaluates outcomes for patients with unresectable colorectal liver metastases (CRLM) undergoing hepatic artery infusion chemotherapy (HAI) and transarterial radioembolization (TARE). The most common liver-directed therapies for unresectable CRLM include HAI and TARE. In this retrospective cohort study, patients with unresectable CRLM treated with HAI at one high-volume center were compared with patients treated with TARE at five other institutions. Propensity score matching was performed within lines of chemotherapy received prior to treatment (treatment-naïve; 1-line; 2-lines; 3-4 lines) using baseline demographics, extrahepatic disease (EHD), prior chemotherapy, disease-free interval, and interval from primary diagnosis to HAI/TARE. Overall survival (OS) analysis was conducted to compare the matched groups. A total of 708 HAI patients and 481 TARE patients were identified. The majority of patients (84%) received chemotherapy prior to HAI/TARE. HAI patients were younger (median age:54 vs. 62) and more likely to have evidence of EHD at time of treatment (65% vs. 60%). Of the 493 patients who received 1-line of chemotherapy, 166 (34%) were matched. Among matched patients who received 1-line (HAI:83, TARE:83) or 2-lines of chemotherapy (HAI:80, TARE:80), TARE patients had a significantly increased risk of all-cause mortality compared to HAI [HR:1.46 (95%CI:1.02-2.08) and HR:1.96 (95%CI:1.32-2.89)]. More frequent conversion to resection and use of concurrent systemic chemotherapy were also seen in the HAI cohort. Among matched patients who received 3-4 lines of chemotherapy (HAI:50, TARE:50), there was no difference in OS between HAI and TARE [HR:0.88 (95%CI:0.57-1.35)] and rate of conversion to surgery was 4% for both groups. Within matched cohorts stratified by lines of therapy, there appear to be differences in survival for patients treated with HAI and TARE after first or second-line chemotherapy. Outcomes after TARE and HAI are not significantly different in the refractory setting.