Chemoembolization Versus Radioembolization for Neuroendocrine Liver Metastases: A Meta-analysis Comparing Clinical Outcomes.

Background: Studies have shown intra-arterial therapies to be effective in controlling neuroendocrine liver metastases (NELMs), but the evidence supporting the selection of specific methods is limited. This meta-analysis is the first to compare survival outcomes between transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) in the treatment of NELM.

Methods: A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in PubMed and Embase databases was conducted in February 2020 for published studies comparing survival outcomes between TACE and TARE in the treatment of NELM.

Results: Six eligible cohort studies with a total of 643 patients were identified. The TACE and TARE groups were similar in terms of age, sex, hepatic tumor burden, tumor grade, and Eastern Cooperative Oncology Group (ECOG) score. The patients treated with TACE had significantly better overall survival (odds ratio [OR], 1.92; 95% confidence interval [CI] 1.14-3.22, p = 0.014) than those treated with TARE. Overall survival ranged from 16.8 to 81.9 months with TACE and from 14.5 to 66.8 months with TARE. No significant differences in hepatic progression-free survival (OR, 1.01; 95% CI 0.75-1.35; p = 0.96) or tumor response were observed within the first 3 months (OR, 2.87; 95% CI 0.81-10.21; p = 0.10) or thereafter (OR, 0.98; 95% CI 0.12-7.86; p = 0.99). The complication rates were similar between the two groups, with 6.9% of the TACE patients versus 8.5% of TARE patients reporting major complications (OR, 1.16; 95% CI 0.54-2.48; p = 0.71) and respectively 44.6% and 58.8% of the TACE and TARE patients reporting minor adverse events (OR, 1.08; 95% CI 0.39-2.99; p = 0.88).

Conclusions: Despite similar tumor responses, an overall survival benefit was associated with TACE treatment of NELM compared with TARE treatment. Randomized controlled trials are warranted to confirm this finding and clarify whether certain subpopulations benefit from different transarterial methods.