Tumor biology and pre-transplant locoregional treatments determine outcomes in patients with T3 hepatocellular carcinoma undergoing liver transplantation

Long-term posttransplant survival outcome following bridging locoregional therapy in hepatocellular carcinoma patients: A systematic review and meta-analysis

Aim

Liver transplantation (LT) is essential due to its curative efficacy, but liver-graft shortages have limited its widespread application. Bridging locoregional therapy (LRT) before LT has been performed to prevent tumor progression, and a recent literature review revealed that it is associated with a nonsignificant trend toward better survival outcomes. However, much more information on bridging therapy has become available since then. This meta-analysis aimed to compare the posttransplant survival and HCC recurrence between patients with and without pretransplant bridging LRT.

Methods

Studies were identified in MEDLINE, SCOPUS, and the Cochrane Library. Two independent researchers screened titles and full articles, extracted relevant data, and conducted a parametric survival analysis.

Results

Out of 4794 studies, 18 cohort studies were eligible. The 1-, 3-, and 5-year overall survival (OS) rates were 93.1%, 85.0%, and 79.1% for those in the bridging LRT group, while they were 91.8%, 81.1%, and 75.5% for those who did not receive LRT, respectively. There were no differences in overall survival between these groups (HR 0.90; 0.78-1.05, P = 0.17). Interestingly, we discovered that bridging therapy helped prolong survival significantly in a high-risk population with a long waiting time (HR 0.76; 0.60-0.96, P = 0.02). Unfortunately, bridging LRT did not improve disease-free survival (HR 0.98; 0.86-1.11, P = 0.70).

Conclusions

The results indicate that bridging LRT does not generally change post-LT outcomes. However, bridging LRT can significantly improve survival in patients with a long waiting time for LT.

Association between bridging therapy and posttransplant outcomes in patients with HCC within Milan criteria: A systematic review and meta-analysis

Liver transplantation is the curative therapy of choice for patients with early-stage HCC. Locoregional therapies are often employed as a bridge to reduce the risk of waitlist dropout; however, their association with posttransplant outcomes is unclear. We conducted a systematic review using Ovid MEDLINE and EMBASE to identify studies published between database inception and August 2, 2023, which reported posttransplant recurrence-free survival and overall survival among patients transplanted for HCC within Milan criteria, stratified by receipt of bridging therapy. Pooled HRs were calculated for each outcome using the DerSimonian and Laird method for a random-effects model. We identified 38 studies, including 19,671 patients who received and 20,148 patients who did not receive bridging therapy. Bridging therapy was not associated with significant differences in recurrence-free survival (pooled HR: 0.91, 95% CI: 0.77-1.08; I2 =39%) or overall survival (pooled HR: 1.09, 95% CI: 0.95-1.24; I2 =47%). Results were relatively consistent across subgroups, including geographic location and study period. Studies were discordant regarding the differential strength of association by pretreatment tumor burden and pathologic response, but potential benefits of locoregional therapy were mitigated in those who received 3 or more treatments. Adverse events were reported in a minority of studies, but when reported occurred in 6%-15% of the patients. Few studies reported loss to follow-up and most had a risk of residual confounding. Bridging therapy is not associated with improvements in posttransplant recurrence-free or overall survival among patients with HCC within Milan criteria. The risk-benefit ratio of bridging therapy likely differs based on the risk of waitlist dropout.

Long-term outcomes of living donor liver transplantation after locoregional treatment for hepatocellular carcinoma: an experience from a single institute

PURPOSE

The precise role of downstaging or bridge therapy for cirrhotic patients with hepatocellular carcinoma (HCC) beyond or within the Milan criteria (MC) before living donor liver transplantation (LDLT) remains undefined.

METHODS

We conducted a single-center, retrospective cohort study of 40 cirrhotic patients with HCC who underwent LDLT from 2000 to 2018. Dynamic computed tomography images at the initial presentation and immediately before LDLT as well as the final histopathological findings were reviewed to determine whether they met or exceeded MC.

RESULTS

Overall, 29 patients underwent various pre-transplant HCC treatments, including ablation and embolization (bridge therapy, n = 20; downstaging, n = 9). Of the 9 patients who were initially beyond the MC, 4 (44.4%) were successfully downstaged to within the MC. Five patients beyond the MC immediately before LDLT demonstrated a significantly worse 5-year overall survival rate than patients within the MC (16.7% vs. 82.2%, P = 0.004), regardless of the radiological HCC stage at presentation or the final pathological tumor status. All 3 recurrent patients had HCC beyond the MC immediately before transplant and died of their disease at 13, 24, and 50 months after transplantation.

CONCLUSIONS

Successful downstaging for HCC cases beyond the MC provides similar outcomes to those within the MC at presentation, regardless of the histopathological findings.

18F-fludeoxyglucose positron emission tomography for diagnosis of HCC: implications for therapeutic strategy in curative and non-curative approaches

Hepatocellular carcinoma (HCC) is a global health issue with increasing incidence and high mortality rate. Depending on the tumor load and extent of underlying liver cirrhosis, aggressive surgical treatment by hepatectomy or liver transplantation (LT) may lead to cure, whereas different modalities of liver-directed locoregional or systemic tumor treatments are currently available for a noncurative approach. Apart from tumor burden and grade of liver dysfunction, assessment of prognostic relevant biological tumor aggressiveness is vitally important for establishing a promising multimodal therapeutic strategy and improving the individual treatment-related risk/benefit ratio. In recent years, an increasing body of clinical evidence has been presented that ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), which is a standard nuclear imaging device in oncology, may serve as a powerful surrogate for tumor invasiveness and prognosis in HCC patients and, thereby, impact individual decision making on most appropriate therapy concept. This review describes the currently available data on the prognostic value of ¹⁸F-FDG PET in patients with early and advanced HCC stages and the resulting implications for treatment strategy.

Surgical Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. In select patients, surgical treatment in the form of either resection or transplantation offers a curative option. The aims of this review are to (1) review the current American Association for the Study of Liver Diseases/European Association for the Study of the Liver guidelines on the surgical management of HCC and (2) review the proposed changes to these guidelines and analyze the strength of evidence underlying these proposals. Three authors identified the most relevant publications in the literature on liver resection and transplantation for HCC and analyzed the strength of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification. In the United States, the liver allocation system provides priority for liver transplantation to patients with HCC within the Milan criteria. Current evidence suggests that liver transplantation may also be indicated in certain patient groups beyond Milan criteria, such as pediatric patients with large tumor burden or adult patients who are successfully downstaged. Patients with no underlying liver disease may also benefit from liver transplantation if the HCC is unresectable. In patients with no or minimal (compensated) liver disease and solitary HCC ≥2 cm, liver resection is warranted. If liver transplantation is not available or contraindicated, liver resection can be offered to patients with multinodular HCC, provided that the underlying liver disease is not decompensated. Many patients may benefit from surgical strategies adapted to local resources and policies (hepatitis B prevalence, organ availability, etc). Although current low-quality evidence shows better overall survival with aggressive surgical strategies, this approach is limited to select patients. Larger and well-designed prospective studies are needed to better define the benefits and limits of such approach.

Impact of remnant vital tissue after locoregional treatment and liver transplant in hepatocellular cancer patients, a multicentre cohort study

The role of pathological findings after locoregional treatments as predictors of hepatocellular cancer recurrence after liver transplantation has been poorly addressed. The aim of the study was to identify the role of remnant vital tissue (RVT) of the target lesion in predicting hepatocellular cancer recurrence. Two hundred and seventy-six patients firstly undergoing locoregional treatment and then transplanted between January 2010 and December 2015 in four European Transplant Centres (i.e. Rome Tor Vergata, Birmingham, Brussels and Ancona) were enrolled in the study to investigate the role of pathological response at upfront locoregional treatment. At multivariable Cox regression analysis, RVT ≥2 cm was a strong independent risk factor for post-LT recurrence (HR = 5.6; P < 0.0001). Five-year disease-free survival rates were 60.8%, 80.9% and 95.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. When only Milan Criteria-IN patients were analysed, similar results were reported, with 5-year disease-free survival rates of 58.1%, 79.0% and 94.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. RVT is an important determinant of tumour recurrence after liver transplantation performed for hepatocellular cancer. Its discriminative power looks to be evident also in a Milan-IN setting, suggesting to more liberally use locoregional treatments also in these patients.

Therapies for patients with hepatocellular carcinoma awaiting liver transplantation: A systematic review and meta-analysis

Patients with hepatocellular carcinoma (HCC) who are listed for liver transplantation (LT) are often treated while on the waiting list with locoregional therapy (LRT), which is aimed at either preventing progression of HCC or reducing the measurable disease burden of HCC in order to receive increased allocation priority. We aimed to synthesize evidence regarding the effectiveness of LRT in the management of patients with HCC who were on the LT waitlist. We conducted a comprehensive search of multiple databases from 1996 to April 25, 2016, for studies that enrolled adults with cirrhosis awaiting LT and treated with bridging or down-staging therapies before LT. Therapies included transcatheter arterial chemoembolization, transarterial radioembolization, ablation, and radiotherapy. We included both comparative and noncomparative studies. There were no randomized controlled trials identified. For adults with T1 HCC and waiting for LT, there were only two nonrandomized comparative studies, both with a high risk of bias, which reported the outcome of interest. In one series, the rate of dropout from all causes at 6 months in T1 HCC patients who underwent LRT was 5.3%, while in the other series of T1 HCC patients who did not receive LRT, the dropout rate at median follow-up of 2.4 years and the progression rate to T2 HCC were 30% and 88%, respectively. For adults with T2 HCC awaiting LT, transplant with any bridging therapy showed a nonsignificant reduction in the risk of waitlist dropout due to progression (relative risk [RR], 0.32; 95% confidence interval [CI], 0.06-1.85; I² = 0%) and of waitlist dropout from all causes (RR, 0.38; 95% CI, 0.060-2.370; I² = 85.7%) compared to no therapy based on three comparative studies. The quality of evidence is very low due to high risk of bias, imprecision, and inconsistency. There were five comparative studies which reported on posttransplant survival rates and 10 comparative studies which reported on posttransplant recurrence, and there was no significant difference seen in either of these endpoints. For adults initially with stage T3 HCC who received LRT, there were three studies reporting on transplant with any down-staging therapy versus no downstaging, and this showed a significant increase in 1-year (two studies, RR, 1.11; 95% CI, 1.01-1.23) and 5-year (1 study, RR, 1.17; 95% CI, 1.03-1.32) post-LT survival rates for patients who received LRT. The quality of evidence is very low due to serious risk of bias and imprecision.

CONCLUSION

In patients with HCC listed for LT, the use of LRT is associated with a nonsignificant trend toward improved waitlist and posttransplant outcomes, though there is a high risk of selection bias in the available evidence. (Hepatology 2018;67:381-400).

Impact of preoperative locoregional therapy on recurrence and patient survival following liver transplantation for hepatocellular carcinoma: a meta-analysis

Abstracts Objective: To evaluate the impact of preoperative locoregional therapy on recurrence and patient survival following liver transplantation for hepatocellular carcinoma (HCC).

METHODS

We searched medical literature databases to identify appropriate studies assessing the impact of preoperative locoregional therapy on recurrence and patient survival following liver transplantation from January 1962 to April 2014. Study inclusion criteria were the existence of a control group, a sufficiently long follow-up period and reporting of survival outcomes. We then performed a meta-analysis of these studies.

RESULTS

Our search identified 12 studies from among a possible 1105. A total of 1504 patients were included in our analysis. There was no significant heterogeneity among the studies. In the meta-analysis, preoperative locoregional therapy was not statistically significant in affecting five-year survival rates following liver transplantation (hazard ratio [HR] = 1.06; 95% confidence interval [CI] = 0.82-1.38). For patients meeting the Milan criteria, preoperative locoregional therapy did not affect survival rates following liver transplantation (HR =1.04, 95% CI =0.74-1.45). The recurrence-free survival rate also had no association with preoperative locoregional therapy (HR =1.02, 95% CI =0.70-1.50).

CONCLUSION

Our meta-analysis suggests that preoperative locoregional therapy has no impact on survival following liver transplantation for HCC.

Progenitor cell markers predict outcome of patients with hepatocellular carcinoma beyond Milan criteria undergoing liver transplantation

BACKGROUND & AIMS

In patients with hepatocellular carcinoma (HCC), liver transplantation (LT) is an excellent therapy if tumor characteristics are within the Milan criteria. We aimed to define genomic features enabling to identify HCC patients beyond Milan criteria who have acceptable transplant outcomes.

METHODS

Among 770 consecutive HCC patients transplanted between 1990 and 2013, 132 had tumors exceeding Milan criteria on pathology and were enrolled in the study; 44% of the patients satisfied the 'up-to-7 rule' [7=sum of the size of the largest tumor and the number of tumors]. Explant tumors were assessed for genomic signatures and immunohistochemical markers associated with poor outcome.

RESULTS

At a median follow-up of 88months, 64 patients had died and 45 recurred; the 5-year overall survival (OS) and recurrence rates were 57% and 35%, respectively. Cytokeratin 19 (CK19) gene signature was independently associated with recurrence [Hazard ratio (HR)=2.95, p<0.001], along with tumor size (HR=3.37, p=0.023) and presence of satellites (HR=2.98, p=0.001). S2 subclass signature was independently associated with poor OS (HR=3.18, p=0.001), along with tumor size (HR=5.06, p<0.001) and up-to-7 rule (HR=2.50, p=0.002). Using the presence of progenitor cell markers (either CK19 or S2 signatures) patients were classified into poor prognosis (n=58; 5-year recurrence 53%, survival 45%) and good prognosis (n=74; 5-year recurrence 19%, survival 67%) (HR=3.16, p<0.001 for recurrence, and HR=1.72, p=0.04 for OS).

CONCLUSIONS

HCC patients transplanted beyond Milan criteria without gene signatures of progenitor markers (CK19 and S2) achieved survival rates similar as those within Milan criteria. Once prospectively validated, these markers may support a limited expansion of LT indications.

Liver transplant for hepatocellular cancer: very small tumors, very large tumors, and waiting time

The role of liver transplant for treatment of early hepatocellular cancer (HCC) is no longer contested. However, its benefit relative to other therapies for patients with very early (<2 cm) HCC is still a matter of debate. Twenty years after the establishment of the Milan criteria, we are beginning to realize that the number and size of tumors may not be the best metric by which to prognosticate outcomes and allocate organs. A better assessment of tumor aggressiveness is clearly needed.

The role of mammalian target of rapamycin inhibitors in the management of post-transplant malignancy

Post-transplant malignancies, which occur either de novo or as cancer recurrences, are due to chronic exposure to immunosuppressive agents and are often more aggressive than those that develop in the non-transplant setting. Mammalian target of rapamycin (mTOR) inhibitors have antitumor and immunosuppressive effects. The dual effects of this class of agents may provide adequate immunosuppression to prevent organ rejection while simultaneously reducing the risk of post-transplant malignancy. mTOR inhibitors have become established approved agents for treating renal cell carcinoma and other cancers and, as reviewed herein, accumulating experience among organ transplant recipients collectively points toward a potential to prevent the development of de novo malignancies of various types in the post-transplant period. To date, most research efforts surrounding mTOR inhibitors and cancer control in the transplant population have been in the area of skin cancer prevention, but there have also been interesting observations regarding regression of post-transplant Kaposi's sarcoma and post-transplantation lymphoproliferative disorder that warrant further study.