Downstaging hepatocellular carcinoma before liver transplantation: A multicenter analysis of the "all-comers" protocol in the Multicenter Evaluation of Reduction in Tumor Size before Liver Transplantation (MERITS-LT) consortium.

Patients with hepatocellular carcinoma meeting united network for organ sharing (UNOS)-downstaging (DS) criteria have excellent liver transplantation (LT) outcomes after DS. However, outcomes for "all-comers" (AC) patients with tumors initially exceeding UNOS-DS are poorly understood. Patients meeting AC (n = 82) or UNOS-DS (n = 229) at 7 LT centers in 4 UNOS regions were prospectively followed from 2015-2020. AC patients had a lower probability of successful DS (67% vs 83% within 12 months; P < .001). The 3-year survival was 69% for UNOS-DS vs 58% for AC (P = .05) and reduced to 30% in patients with Child-Pugh B/C cirrhosis or alpha-fetoprotein (AFP) ≥ 500. Five-year LT probability was 42% for AC vs 74% in UNOS-DS (P = .10). Thirty-eight percent were understaged on explant, with the increasing sum of the largest tumor diameter plus the number of lesions before LT (odds ratio 1.3; P = .01) and AFP ≥ 20 (odds ratio 5.9; P = .005) associated with understaging. Post-LT 3-year survival was 91% for AC vs 81% for UNOS-DS (P = .67). In this first prospective multiregional study of AC patients from the multicenter evaluation of reduction in tumor size before liver transplantation (MERITS-LT) consortium, we observed a 65% probability of successful DS. Three-year survival in AC was nearly 60%, though AC with Child-Pugh B/C or AFP ≥ 500 had poor survival. Explant pathology and 3-year post-LT outcomes were similar between cohorts, suggesting that LT is a reasonable goal in selected AC patients.

Downstaging Outcomes for Hepatocellular Carcinoma: Results From the Multicenter Evaluation of Reduction in Tumor Size before Liver Transplantation (MERITS-LT) Consortium.

BACKGROUND & AIMS: United Network of Organ Sharing (UNOS) has adopted uniform criteria for downstaging (UNOS-DS) of hepatocellular carcinoma (HCC) before liver transplantation (LT), but the downstaging success rate and intention-to-treat outcomes across broad geographic regions are unknown. METHODS: In this first multiregional study (7 centers, 4 UNOS regions), 209 consecutive patients with HCC undergoing downstaging based on UNOS-DS criteria were prospectively evaluated from 2016 to 2019. RESULTS: Probability of successful downstaging to Milan criteria and dropout at 2 years from the initial downstaging procedure was 87.7% and 37.3%, respectively. Pretreatment with lectin-reactive α-fetoprotein ≥10% (hazard ratio, 3.7; P = .02) was associated with increased dropout risk. When chemoembolization (n = 132) and yttrium-90 radioembolization (n = 62) were compared as the initial downstaging treatment, there were no differences in Modified Response Evaluation Criteria In Solid Tumors response, probability of or time to successful downstaging, waiting list dropout, or LT. Probability of LT at 3 years was 46.6% after a median of 17.2 months. In the explant, 17.5% had vascular invasion, and 42.8% exceeded Milan criteria (understaging). The only factor associated with understaging was the sum of the number of lesions plus largest tumor diameter on the last pre-LT imaging, and the odds of understaging increased by 35% per 1-unit increase in this sum. Post-LT survival at 2 years was 95%, and HCC recurrence occurred in 7.9%. CONCLUSION: In this first prospective multiregional study based on UNOS-DS criteria, we observed a successful downstaging rate of >80% and similar efficacy of chemoembolization and yttrium-90 radioembolization as the initial downstaging treatment. A high rate of tumor understaging was observed despite excellent 2-year post-LT survival of 95%. Additional LRT to reduce viable tumor burden may reduce tumor understaging.

Morphological heterogeneity in beta-catenin-mutated hepatocellular carcinomas: implications for tumor molecular classification.

Beta-catenin (CTNNB1) is commonly mutated in hepatocellular carcinoma (HCC). CTNNB1-mutated HCC has important clinical correlates, such as being immune cold and less likely to respond to immune checkpoint inhibitor therapies. It remains unclear, however, if they are a morphologically homogenous group of tumors. To better understand the association between the morphology, CTNNB1 mutations, and other molecular features, a detailed study of 338 The Cancer Genome Atlas cases was performed. A characteristic histological morphology was strongly associated with CTNNB1 mutations but was present in only 58% of CTNNB1-mutated HCCs. Tumors with APC mutations tended to have the classic morphology; those with AXIN mutations did not. Pseudoglands are a key feature of the classic morphology, and they were associated with CTNNB1 mutations, male gender, specific CTNNB1 mutation site, and lack of TP53 mutations. Differential gene expression analysis stratified by the presence/absence of pseudoglands identified 60 differentially expressed genes (FDR <5%); clustering according to these differentially expressed genes revealed three groups of tumors, one with pseudoglands and a strong association with genes regulated by Wnt signaling; within this group, TP53 mutations were associated with a loss of the typical morphology of CTNNB1-mutated HCCs. When stratified by gender, further differential gene expression showed Wnt-regulated genes were associated with pseudoglands in men but not women. These findings indicate HCC with CTNNB1 mutations are morphologically heterogeneous, with gene penetrance for morphology dependent in part on gender, specific CTNNB1 mutations, and co-occurring TP53 mutations. This heterogeneity has important implications for the classification of HCC.

Hepatocellular carcinoma in nonalcoholic fatty liver disease: A growing challenge.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide, and its prevalence increases continuously. As it predisposes to hepatocellular carcinoma both in the presence and in the absence of cirrhosis, it is not surprising that the incidence of NAFLD-related hepatocellular carcinoma would also rise. Some of the mechanisms involved in hepatocarcinogenesis are particular to individuals with fatty liver, and they help explain why liver cancer develops even in patients without cirrhosis. Genetic and immune-mediated mechanisms seem to play an important role in the development of hepatocellular carcinoma in this population. Currently, it is consensual that patients with NAFLD-related cirrhosis should be surveilled with ultrasonography every 6 mo (with or without alpha-fetoprotein), but it is known that they are less likely to follow this recommendation than individuals with other kinds of liver disease. Moreover, the performance of the methods of surveillance are lower in NAFLD than they are in other liver diseases. Furthermore, it is not clear which subgroups of patients without cirrhosis should undergo surveillance. Understanding the mechanisms of hepatocarcinogenesis in NAFLD could hopefully lead to the identification of biomarkers to be used in the surveillance for liver cancer in these individuals. By improving surveillance, tumors could be detected in earlier stages, amenable to curative treatments.

The Liver in Oncology.

Gastroenterologists and hepatologists will encounter oncology patients who develop abnormal liver tests, patients with hepatic malignancies, and patients with acute and chronic liver disease who require chemotherapy or immediate evaluation. Chemotherapy can cause liver injury owing to toxic effects or idiosyncratic reactions. Immune checkpoint inhibitors may be associated with autoimmune-mediated liver toxicities. Venoocclusive disease requires immediate evaluation. Nodular regenerative hyperplasia is a chronic progressive disorder. Screening and prophylaxis for reactivation of hepatitis B is important to minimize complications in patients receiving chemotherapy. Patients with metastatic lesions can undergo resection or ablation. Hepatic injury may occur in those receiving radiation-based therapies.