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

Ten-Year Outcomes of Liver Transplant and Downstaging for Hepatocellular Carcinoma

Importance

National guidelines on transplant selection have adopted successful downstaging to within Milan criteria (MC) as a viable option for the treatment of hepatocellular carcinoma (HCC) before liver transplant (LT). Recurrence of HCC after LT carries a poor prognosis, and treatment modalities remain challenging.

Objective

To establish the 10-year outcomes of patients with HCC after LT in a large, multicenter US study based on individual data; provide robust data on the long-term role of downstaging; and evaluate the association of treatment modalities with postrecurrence survival.

Design, Setting, and Participants

In this cohort study, a retrospective, multicenter analysis of prospectively collected data was conducted for 2645 adults who had undergone LT for HCC at 5 US academic centers between January 2001 and December 2015. The analysis was performed from May 2019 through June 2021. Outcomes of 341 patients whose disease was downstaged to within MC were compared with those in 2122 patients whose disease was always within MC and 182 patients whose disease was not downstaged. The associations of tumor and treatment factors on postrecurrence survival were analyzed using Cox proportional hazards regression and multivariable logistic regression models.

Main Outcomes and Measures

The primary outcome was overall survival for the whole cohort and according to downstaging status. Secondary outcomes were time to recurrence, recurrence-free survival, and recurrence after specific post-LT therapies.

Results

Of the 2645 patients studied, the median age was 59.9 years (IQR, 54.7-64.7 years). The majority of the patients were men (2028 [76.7%] vs 617 [23.3%] women). The 10-year post-LT survival and recurrence rates were, respectively, 52.1% and 20.6% among those whose disease was downstaged; 61.5% and 13.3% in those always within MC; and 43.3% and 41.1% in those whose disease was not downstaged. Independent variables associated with downstaging failure were tumor size greater than 7 cm at diagnosis (OR, 2.62; 95% CI, 1.20-5.75; P = .02), more than 3 tumors at diagnosis (OR, 2.34; 95% CI, 1.22-4.50; P = .01), and α-fetoprotein response of at least 20 ng/mL with less than 50% improvement from maximum α-fetoprotein before LT (OR, 1.99; 95% CI, 1.14-3.46; P = .02). Surgically treated patients with recurrent HCC differed in clinicopathologic characteristics and had improved 5-year postrecurrence survival rates (31.6% vs 7.3%; P < .001).

Conclusions and Relevance

In a large, multicenter cohort of patients with HCC successfully downstaged to within MC, 10-year post-LT outcomes were excellent, validating national downstaging policies and showing a clear utility benefit for LT prioritization decision making. Surgical management of HCC recurrence after LT was associated with improved survival in well-selected patients and should be pursued, if feasible.

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.

Is liquid biopsy the future commutator of decision-making in liver transplantation for hepatocellular carcinoma?

Liver transplant (LT) is the most favorable treatment option for patients with early stage hepatocellular carcinoma (HCC). Numerous attempts have been pursued to establish eligibility criteria and select HCC patients for LT, leading to various systems that essentially integrate clinico-morphological variables. Lacking of sufficient granularity to recapitulate the biological complexity of the disease, all these alternatives display substantial limitations and are thus undeniably imperfect. Liquid biopsy, defined as the molecular analysis of circulating analytes released by a cancer into the bloodstream, was revealed as an incomparable tool in the management of cancers, including HCC. It appears as an ideal candidate to refine selection criteria of LT in HCC. The present comprehensive review analyzed the available literature on this topic. Data in the field, however, remain scarce with only 17 studies. Although rare, these studies provided important and encouraging findings highlighting notable prognostic values and supporting the contribution of liquid biopsy in this specific clinical scenario. These results underpinned the critical and urgent need to intensify and accelerate research on liquid biopsy, in order to determine whether and how liquid biopsy may be integrated in the decision-making of LT in HCC.

Intraarterial Therapies for the Management of Hepatocellular Carcinoma

Image-guided locoregional therapies play a crucial role in the management of patients with hepatocellular carcinoma (HCC). Transarterial therapies consist of a group of catheter-based treatments where embolic agents are delivered directly into the tumor via their supplying arteries. Some of the transarterial therapies available include bland embolization (TAE), transarterial chemoembolization (TACE), drug-eluting beads-transarterial chemoembolization (DEB-TACE), selective internal radioembolization therapy (SIRT), and hepatic artery infusion (HAI). This article provides a review of pre-procedural, intra-procedural, and post-procedural aspects of each therapy, along with a review of the literature. Newer embolotherapy options and future directions are also briefly discussed.

[Hepatocellular carcinoma]

The therapeutic spectrum of hepatocellular carcinoma (HCC) in cirrhosis has expanded over the last decade and consists of surgical, interventional and systemic approaches. The tumor stage and liver function are important for the therapeutic strategy. Curation can be achieved by liver resection or transplantation. Access to transplantation is limited by organ shortage and waiting time. Locoregional therapies can be used as a bridge to transplant or for down-sizing in a neoadjuvant setting as well as palliative therapy. Advanced stages might benefit from systemic or immunotherapy. Modern multimodal therapy planning, timing and reevaluation are part of the tasks of tumor boards specialised in the liver, including the option of liver transplantation. Therapies can be used alone or in combination and according to the experience of the center. A curative strategy should always be pursued at initial presentation.

Radiofrequency ablation versus trans-arterial chemoembolization in patients with HCC awaiting liver transplant: an analysis of the Scientific Registry of Transplant Recipients

PURPOSE

To evaluate differences in waitlist mortality/dropout for liver transplant candidates with hepatocellular carcinoma (HCC) who undergo radiofrequency ablation (RFA) versus trans-arterial chemoembolization (TACE).

MATERIAL AND METHODS

From 2004-2013, 11,824 patients in the Scientific Registry of Transplant Recipients (SRTR) with HCC who underwent RFA or TACE. Patients were followed until December 31, 2019 or 5 years, whichever came first and stratified by Milan criteria. Competing risk and Cox regression analyses to compare waitlist mortality/dropout were performed with adjusted hazard ratios (asHR, reference group RFA). Regression models were adjusted for age, race, sex, calculated Model for End Stage Liver Disease (cMELD) score, tumor size, and number.

RESULTS

There was no difference in waitlist mortality/dropout for patients outside Milan criteria (N = 1,226) between TACE (19.2%) compared to RFA (19.0%) (asHR 0.91; 95% CI 0.79-1.03). There was also no difference for patients inside Milan criteria (N = 10,598) in waitlist mortality/dropout (TACE 13.4% vs. RFA 12.9%) (asHR 1.29; 95% CI 0.79-2.09). Subgroup analysis within Milan criteria demonstrated no evidence of difference in TACE compared to RFA in patients with single tumor ≤3 cm (asHR 0.92; 95% CI 0.77-1.10), single tumor > 3 cm (asHR 1.03; 95% CI 0.79-1.34), or with > 1 tumor (asHR 0.89; 95% CI 0.72-1.09).

CONCLUSION

Using national registry data, no difference was found in waitlist mortality/dropout for transplant candidates with HCC who received TACE vs. RFA.

Emerging curative-intent minimally-invasive therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common cause of liver malignancy and the fourth leading cause of cancer deaths universally. Cure can be achieved for early stage HCC, which is defined as 3 or fewer lesions less than or equal to 3 cm in the setting of Child-Pugh A or B and an ECOG of 0. Patients outside of these criteria who can be down-staged with loco-regional therapies to resection or liver transplantation (LT) also achieve curative outcomes. Traditionally, surgical resection, LT, and ablation are considered curative therapies for early HCC. However, results from recently conducted LEGACY study and DOSISPHERE trial demonstrate that transarterial radio-embolization has curative outcomes for early HCC, leading to its recent incorporation into the Barcelona clinic liver criteria guidelines for early HCC. This review is based on current evidence for curative-intent loco-regional therapies including radioembolization for early-stage HCC.

Liver-Directed and Systemic Therapy Options for Hepatocellular Carcinoma

Liver transplant and resection are preferable for the management of hepatocellular carcinoma, but ultimately, tumor location, biology, and patient condition dictate treatment decisions. At the NCCN 2022 Annual Conference, a panel of experts used 3 case studies to develop an evidence-based approach to the treatment of similar patients with hepatocellular carcinoma. Moderated by Daniel B. Brown, MD, FSIR, the session focused on current research regarding liver-directed and systemic therapy options.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Simple Summary

The ideal treatment for hepatocellular carcinoma (HCC) is liver transplantation (LT), which both eliminates the HCC and cures the diseased liver. Once considered an experimental treatment with dismal survival rates, LT for HCC entered a new era with the establishment of the Milan criteria over 20 years ago. However, over the last two decades, the Milan criteria, which are based on tumor morphology, have come under intense scrutiny and are now largely regarded as too restrictive, and limit the access of transplantation for many patients who would otherwise achieve good clinical outcomes. The liver transplant community has been making every effort to reach a goal of establishing more reliable selection criteria. This article addresses how the criteria have been extended, as well as the concept of pre-transplant down-staging to maximize the eligibility.

Abstract

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Upper Limits of Downstaging for Hepatocellular Carcinoma in Liver Transplantation

Simple Summary

Currently, most transplant centres worldwide accept patients with hepatocellular carcinoma who underwent successful downstaging. Concurrently, the effectiveness of radiological and systemic therapies used for the downstaging of hepatocellular carcinoma are increasing. It is now more frequently observed that candidates for liver transplantation have an excellent response to downstaging, even if the baseline stage was well beyond the transplantable tumour. Downstaged patients have a higher risk of dropout from the waiting list and post-transplant recurrence if not transplanted in a short time. Since an increasing number of downstaged patients affects the waitlist dynamics, the definition of upper limits of downstaging is becoming a crucial issue. In this narrative review, we summarise current evidence on the downstaging of hepatocellular carcinoma for liver transplantation, including downstaging of patients with macrovascular invasion or extrahepatic metastasis at presentation and employment of the new systemic treatments for hepatocellular carcinoma.

Abstract

In Europe and the United States, approximately 1100 and 1800 liver transplantations, respectively, are performed every year for hepatocellular carcinoma (HCC), compared with an annual incidence of 65,000 and 39,000 new cases, respectively. Because of organ shortages, proper patient selection is crucial, especially for those exceeding the Milan criteria. Downstaging is the reduction of the HCC burden to meet the eligibility criteria for liver transplantation. Many techniques can be used in downstaging, including ablation, chemoembolisation, radioembolisation and systemic treatments, with a reported success rate of 60–70%. In recent years, an increasing number of patient responders to downstaging procedures has been included in the waitlist, generally with a comparable five-year post-transplant survival but with a higher probability of dropout than HCC patients within the Milan criteria. While the Milan criteria are generally accepted as the endpoint of downstaging, the upper limits of tumour burden for downstaging HCC for liver transplantation are controversial. Very challenging situations involve HCC patients with large nodules, macrovascular invasion or even extrahepatic metastasis at baseline who respond to increasingly more effective downstaging procedures and who aspire to be placed on the waitlist for transplantation. This narrative review analyses the most important evidence available on cohorts subjected to “extended” downstaging, including HCC patients over the up-to-seven criteria and over the University of California San Francisco downstaging criteria. We also address surrogate markers of biological aggressiveness, such as alpha-fetoprotein and the response stability to locoregional treatments, which are very useful in selecting responders to downstaging procedures for waitlisting inclusion.

Locoregional Treatments for Bridging and Downstaging HCC to Liver Transplantation

Liver transplantation (LT) is the first-line treatment for patients diagnosed with unresectable early-stage hepatocellular carcinoma (HCC) in the setting of cirrhosis. It is well known that HCC patients within the Milan criteria (solitary tumour ≤ 5 cm or ≤3 tumours, each <3 cm) could undergo LT with excellent results. However, there is a growing tendency to enlarge inclusion criteria since the Milan criteria are nowadays considered too restrictive and may exclude patients who would benefit from LT. On the other hand, there is a persistent shortage of donor organs. In this scenario, there is consensus about the role of loco-regional therapy (LRT) during the waiting list to select patients who would benefit more from LT, reducing the risk of drop off from the waiting list as well as decreasing tumour dimension to meet acceptable criteria for LT. In this review, current evidence on the safety, efficacy and utility of LRTs as neoadjuvant therapies before LT are summarized.