National Experience on Waitlist Outcomes for Down-Staging of Hepatocellular Carcinoma: High Dropout Rate in All-Comers

BACKGROUND & AIMS

The United Network for Organ Sharing (UNOS) grants priority listing for liver transplant for patients with hepatocellular carcinoma after successful down-staging to Milan criteria. We evaluated the national experience on down-staging by comparing 2 down-staging groups: tumor burden meeting UNOS down-staging (UNOS-DS) inclusion criteria, and all-comers (AC)-DS with initial tumor burden beyond UNOS-DS criteria vs patients always within Milan criteria.

METHODS

We performed a retrospective analysis of the UNOS database of 23,398 patients listed for liver transplant who had submitted a hepatocellular carcinoma Model for End-Stage Liver Disease exception application from 2010 to 2019, classified as always within Milan (n = 20,579), UNOS-DS (n = 2151), and AC-DS (n = 668).

RESULTS

The 2-year cumulative probabilities of dropout were 19% for Milan, 25% for UNOS-DS (P < .001), and 30% for AC-DS (P < .001). In multivariate analysis of the down-staging groups, factors predicting dropout included Model for End-Stage Liver Disease at listing (hazard ratio [HR], 1.06; P < .001) and initial total tumor diameter (HR, 1.04; P = .002). Compared with α-fetoprotein (AFP) level ≤20 ng/mL, AFP levels of 21 to 100, 101 to 1000, and greater than 1000 ng/mL were associated with a higher risk of dropout (HRs, 1.63, 2.06, and 4.58, respectively; P < .001). A subset of all-comers with AFP levels greater than 100 ng/mL had a 2-year probability of dropout of 52% vs 26% for all others beyond Milan criteria (P < .001).

CONCLUSIONS

All-comers had a significantly higher risk for waitlist dropout compared with the UNOS-DS and Milan groups after initial successful down-staging to Milan criteria. In particular, the subgroup of AC-DS with an AFP level greater than 100 ng/mL had a greater than 50% probability of dropout in the next 2 years. These observations suggest a high likelihood of failure when expanding the indications for down-staging.

UNOS Down-Staging Criteria for Liver Transplantation of Hepatocellular Carcinoma: Systematic Review and Meta-Analysis of 25 Studies

BACKGROUND & AIMS

Down-staging is commonly used to select patients with hepatocellular carcinoma (HCC) beyond Milan criteria (MC) for liver transplantation (LT), but outcomes are heterogenous. We aimed to estimate pooled down-staging success rates, HCC recurrence, and overall survival (OS), stratified by criteria used for baseline tumor burden.

METHODS

We searched Pubmed and EMBASE databases from inception until August 2021 for studies reporting down-staging success (reduction of tumor burden to within MC) and outcomes of adult HCC patients. In addition, we performed a pooled analysis using reconstructed individual participant data to obtain robust estimates for OS.

RESULTS

We screened 1059 articles and included 25 articles involving 3997 patients. Overall, 55.16% (45.49%-64.46%) underwent successful down-staging, and 31.52% (24.03%-40.11%) received LT (by intention-to-treat analysis [ITT]). Among patients who received LT, 16.01% (11.80%-21.37%) developed HCC recurrence. Comparing studies that used the United Network for Organ Sharing Down-Staging (UNOS-DS) criteria versus studies beyond UNOS-DS or did not specify criteria, down-staging success (by ITT) was 83.21% versus 45.93%, P < .001; the proportion who received LT (by ITT) was 48.61% vs 28.60%, P = .030; and HCC recurrence (among patients who received LT) occurred in 9.06% versus 20.42%, P < .001. Among studies that used UNOS-DS criteria, ITT 1- and 5-year OS from the initiation of down-staging treatment was 86% and 58%, respectively, whereas 1- and 5-year post-LT OS was 94% and 74%, respectively.

CONCLUSIONS

Among studies that adhered to UNOS-DS criteria, down-staging was successful in four-fifths of patients, >50% received LT, and post-LT outcomes were excellent. These data provide clinical validation for the utilization of UNOS-DS criteria.