Downstaging Therapies for Patients with Hepatocellular Carcinoma Awaiting Liver Transplantation: A Systematic Review and Meta-Analysis on Intention-to-Treat Outcomes

SIMPLE SUMMARY: Downstaging therapies provides a viable alternative approach for expanding the MC limits and selecting a subgroup of patients whose LT candidacy would otherwise be disregarded. However, data on downstaging are still controversial due to a variety of reasons, such as differences in LRT, the wide variability in waiting time before LT and, particularly, the lack of intention-to-treat (ITT) analyses. This article is a systematic review and intends to synthesise the existing evidence about the effectiveness of downstaging therapies, aiming to: (a) assess outcomes from ITT analysis of patients with liver cirrhosis and HCC beyond the listing criteria and selected for downstaging protocol, in comparison with HCC within the listing criteria; (b) evaluate outcomes of patients with liver cirrhosis HCC beyond the listing criteria successfully downstaged and transplanted versus those not transplanted. ABSTRACT: Background: Locoregional therapies (LRTs) are commonly used to increase the number of potential candidates for liver transplantation (LT). The aim of this paper is to assess the outcomes of LRTs prior to LT in patients with hepatocellular carcinoma (HCC) beyond the listing criteria. Methods: In accordance with the PRISMA guidelines, we searched the Medline and Web of Science databases for reports published before May 2021. We included papers assessing adult patients with HCC considered for LT and reporting intention-to-treat (ITT) survival outcomes. Two reviewers independently identified and extracted the data and evaluated the papers. Outcomes analysed were drop-out rate; time on the waiting list; and 1, 3 and 5 year survival after LT and based on an ITT analysis. Results: The literature search yielded 3,106 records, of which 11 papers (1874 patients) met the inclusion criteria. Patients with HCC beyond the listing criteria and successfully downstaged presented a higher drop-out rate (OR 2.05, 95% CI 1.45–2.88, p < 0.001) and a longer time from the initial assessment to LT than those with HCC within the listing criteria (MD 1.93, 95% CI 0.91–2.94, p < 0.001). The 1, 3 and 5 year survival post-LT and based on an ITT analysis did not show significant differences between the two groups. Patients with HCC beyond the listing criteria, successfully downstaged and then transplanted, presented longer 3 year (OR 3.77, 95% CI 1.26–11.32, p = 0.02) and 5 year overall survival (OS) (OR 3.08, 95% CI 1.15–8.23, p = 0.02) in comparison with those that were not submitted to LT. Conclusions: Patients with HCC beyond the listing criteria undergoing downstaging presented a higher drop-out rate in comparison with those with HCC within the listing criteria. However, the two groups did not present significant differences in 1, 3 and 5 year survival rates based on an ITT analysis. Patients with HCC beyond the listing, when successfully downstaged and transplanted, presented longer 3 and 5-year OS in comparison with those who were not transplanted.