Loco-regional therapies for patients with hepatocellular carcinoma awaiting liver transplantation: Selecting an optimal therapy

Long-term outcomes of more than a decade treating patients with stereotactic body radiation therapy for hepatocellular carcinoma

Purpose/Objectives

To evaluate if stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) has a durable effect on tumor control and can be delivered safely.

Materials/Methods

Patients included in this retrospective study have been treated at our institution from January 2008 to December 2022. Eligibility criteria were diagnosis of HCC, BCLC stage 0-A-B, non-cirrhotic liver or liver with cirrhosis Child-Pugh class A, and a maximum of three lesions with a cumulative diameter of ≤ 6 cm. Patients with relapses after surgery, thermal ablation or TACE or patients awaiting transplant were also candidates for SBRT. SBRT was delivered in 6 fractions of 8 or 9 Gy. The primary endpoint was local (target) control (LC). Secondary endpoints were time to progression (TTP), overall survival (OS), response rate (RR) and toxicity.

Results

A total of 52 patients received SBRT at our institution and 51 were included in this study. One patient objected and was excluded. Median follow-up was 2.1 years for LC and 2.3 years for OS. Median tumor size was 26 mm. LC rates at 1, 2, and 5 years were 100 %, 95 % and 95 % respectively. Median TTP was 45.6 months. Median OS was 7.1 years. RR was 96 %. No patients in this study have experienced SBRT related CTC AE grade ≥ 3 toxicity.

Conclusion

SBRT resulted in excellent long-term local control rates and absence of severe toxicity in a group of HCC patients. The reported outcomes compare favorably with other local therapies. SBRT should be considered as one of the available local treatment options for HCC.

Feasibility of Liver Transplantation after 90 Y Radioembolization: Lessons from a Radiation Protection Incident

ABSTRACT

Radioembolization using 90 Y is a growing procedure in nuclear medicine for treating hepatocellular carcinoma. Current guidelines suggest postponing liver transplantation or surgical resection for a period of 14 to 30 d after radioembolization to minimize surgeons' exposure to ionizing radiation. In light of a radiation protection incident, we reevaluated the minimum delay required between radioembolization and subsequent liver transplantation. A patient with a hepatocellular carcinoma underwent a liver transplantation 44 h after undergoing radioembolization using 90 Y (860 MBq SIR-Spheres). No specific radioprotection measures were followed during surgery and pathological analysis. We subsequently (1) evaluated the healthcare professionals' exposure to ionizing radiation by conducting dose rate measurements from removed liver tissue and (2) extrapolated the recommended interval to be observed between radioembolization and surgery/transplantation to ensure compliance with the radiation dose limits for worker safety. The surgeons involved in the transplantation procedure experienced the highest radiation exposure, with whole-body doses of 2.4 mSv and extremity doses of 24 mSv. The recommended delay between radioembolization and liver transplantation was 8 d when using SIR-Spheres and 15 d when injecting TheraSphere. This delay can be reduced further when considering the specific 90 Y activity administered during radioembolization. This dosimetric study suggests the feasibility of shortening the delay for liver transplantation/surgery after radioembolization from the 8th or 15th day after using SIR-Spheres or TheraSphere, respectively. This delay can be decreased further when adjusted to the administrated activity while upholding radiation protection standards for healthcare professionals.

Treatment Patterns and Recommendations for Improving the Management of Hepatocellular Carcinoma in Saudi Arabia

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer in the world associated with high morbidity and mortality. Despite being a significant healthcare burden there is limited information on the unmet needs and current treatment practices for intermediate and advanced-stage HCC in Saudi Arabia. This article analyzes the gaps and provides expert consensus on the management strategies for unresectable HCC in Saudi Arabia. A pre-meeting online questionnaire, comprising 20 objective questions about the treatment landscape and diagnosis of HCC in Saudi Arabia, was distributed to experts in the field of HCC management. An advisory board meeting including a panel of 13 experts was held in September 2022 where the responses to the survey questionnaire were reviewed and discussed. The survey results and experts' discussion highlighted the growing incidence of liver cancer in Saudi Arabia. HCC comprised the majority of all liver cancer cases due to rising rates of chronic viral infections and lifestyle-related risk factors. Most physicians in Saudi Arabia follow the Barcelona Clinic Liver Cancer guidelines as a prognostic tool for the detection and staging of patients with HCC. Most of the patients with HCC in Saudi Arabia are diagnosed in the intermediate or advanced stages with poor prognoses and limited therapeutic options. Establishing evidence-based surveillance techniques, a multidisciplinary approach to diagnosis, and better accessibility of treatment options is vital for the management of HCC in Saudi Arabia.

UBE2O reduces the effectiveness of interferon-α via degradation of IFIT3 in hepatocellular carcinoma

Interferon (IFN) exerts its effects through interferon-stimulated genes (ISGs), but its efficacy is limited by interferon resistance, which can be caused by the ubiquitination of key proteins. UBE2O was initially identified as a promising therapeutic target based on data from the TCGA and iUUCD 2.0 databases. Through the inhibition of UBE2O, interferon α/β signaling and overall interferon signaling were activated. Integrating data from proteomic, mass spectrometry, and survival analyses led to the identification of IFIT3, a mediator of interferon signaling, as a ubiquitination substrate of UBE2O. The results of in vitro and in vivo experiments demonstrated that the knockdown of UBE2O can enhance the efficacy of interferon-α by upregulating IFIT3 expression. K236 was identified as a ubiquitination site in IFIT3, and the results of rescue experiments confirmed that the effect of UBE2O on interferon-α sensitivity is dependent on IFIT3 activity. ATO treatment inhibited UBE2O and increased IFIT3 expression, thereby increasing the effectiveness of interferon-α. In conclusion, these findings suggest that UBE2O worsens the therapeutic effect of interferon-α by targeting IFIT3 for ubiquitination and degradation.

Early-Stage HCC Percutaneous Locoregional Management: East versus West Perspectives

Hepatocellular carcinoma represents an important cause of death worldwide. Early-stage hepatocellular carcinoma patients not suitable for surgery can be treated with a variety of minimally invasive locoregional interventional oncology techniques. Various guidelines in different countries address the treatment of hepatocellular carcinoma, but the actual treatment is usually discussed by a multidisciplinary tumor board in a personalized manner, leading to potential treatment differences based on Western and Eastern perspectives. The aim of this paper is to integrate literature evidence with the eminent experiences collected during a focused session at the Mediterranean Interventional Oncology (MIO) Live Congress 2023.

Evolving Landscape in Liver Transplantation for Hepatocellular Carcinoma: From Stage Migration to Immunotherapy Revolution

Liver transplantation (LT) represents the primary curative option for HCC. Despite the extension of transplantation criteria and conversion with down-staging loco-regional treatments, transplantation is not always possible. The introduction of new standards of care in advanced HCC including a combination of immune checkpoint inhibitor-based therapies led to an improvement in response rates and could represent a promising strategy for down-staging the tumor burden. In this review, we identify reports and series, comprising a total of 43 patients who received immune checkpoint inhibitors as bridging or down-staging therapies prior to LT. Overall, treated patients registered an objective response rate of 21%, and 14 patients were reduced within the Milan criteria. Graft rejection was reported in seven patients, resulting in the death of four patients; in the remaining cases, LT was performed safely after immunotherapy. Further investigations are required to define the duration of immune checkpoint inhibitors, their minimum washout period and the LT long-term safety of this strategy. Some randomized clinical trials including immunotherapy combinations, loco-regional treatment and/or tyrosine kinase inhibitors are ongoing and will likely determine the appropriateness of immune checkpoint inhibitors' administration before LT.

Comparison of Ablation Performance between Octopus Multipurpose Electrode and Conventional Octopus Electrode

OBJECTIVE

To compare Octopus multipurpose (MP) electrodes, which are capable of saline instillation and direct tissue temperature measurement, and conventional electrodes for radiofrequency ablation (RFA) in porcine livers in vivo.

MATERIALS AND METHODS

Sixteen pigs were used in this study. In the first experiment, RFA was performed in the liver for 6 minutes using Octopus MP electrodes (n = 15 ablation zones) and conventional electrodes (n = 12 ablation zones) to investigate the effect of saline instillation. The ablation energy, electrical impedance, and ablation volume of the two electrodes were compared. In the second experiment, RFA was performed near the gallbladder (GB) and colon using Octopus MP electrodes (n = 12 ablation zones for each) with direct tissue temperature monitoring and conventional electrodes (n = 11 ablation zones for each). RFA was discontinued when the temperature increased to > 60\xe2\x84\x83 in the Octopus MP electrode group, whereas RFA was performed for a total of 6 minutes in the conventional electrode group. Thermal injury was assessed and compared between the two groups by pathological examination.

RESULTS

In the first experiment, the ablation volume and total energy delivered in the Octopus MP electrode group were significantly larger than those in the conventional electrode group (15.7 ± 4.26 cm³ vs. 12.5 ± 2.14 cm³, p = 0.027; 5.48 ± 0.49 Kcal vs. 5.04 ± 0.49 Kcal, p = 0.029). In the second experiment, thermal injury to the GB and colon was less frequently noted in the Octopus MP electrode group than that in the conventional electrode group (16.7% [2/12] vs. 90.9% [10/11] for GB and 8.3% [1/12] vs. 90.9% [10/11] for colon, p < 0.001 for all). The total energy delivered around the GB (2.65 ± 1.07 Kcal vs. 5.04 ± 0.66 Kcal) and colon (2.58 ± 0.57 Kcal vs. 5.17 ± 0.90 Kcal) were significantly lower in the Octopus MP electrode group than that in the conventional electrode group (p < 0.001 for all).

CONCLUSION

RFA using the Octopus MP electrodes induced a larger ablation volume and resulted in less thermal injury to the adjacent organs compared with conventional electrodes.

UBE2T-mediated Akt ubiquitination and Akt/β-catenin activation promotes hepatocellular carcinoma development by increasing pyrimidine metabolism

The oncogene protein ubiquitin-conjugating enzyme E2T (UBE2T) is reported to be upregulated in hepatocellular carcinoma (HCC) and correlated with poor clinical outcomes of HCC patients. However, the underlying mechanism by which UBE2T exerts its oncogenic function in HCC remains largely unexplored. In this study, in vitro and in vivo experiments suggested that UBE2T promoted HCC development including proliferation and metastasis. GSEA analysis indicated that UBE2T was positively correlated with pyrimidine metabolism, and LC/MS-MS metabolomics profiling revealed that the key products of pyrimidine metabolism were significantly increased in UBE2T-overexpressing cells. UBE2T overexpression led to the upregulation of several key enzymes catalyzing de novo pyrimidine synthesis, including CAD, DHODH, and UMPS. Moreover, the utilization of leflunomide, a clinically approved DHODH inhibitor, blocked the effect of UBE2T in promoting HCC progression. Mechanistically, UBE2T increased Akt K63-mediated ubiquitination and Akt/β-catenin signaling pathway activation. The disruption of UBE2T-mediated ubiquitination on Akt, including E2-enzyme-deficient mutation (C86A) of UBE2T and ubiquitination-site-deficient mutation (K8/14 R) of Akt impaired UBE2T’s effect in upregulating CAD, DHODH, and UMPS. Importantly, we demonstrated that UBE2T was positively correlated with p-Akt, β-catenin, CAD, DHODH, and UMPS in HCC tumor tissues. In summary, our study indicates that UBE2T increases pyrimidine metabolism by promoting Akt K63-linked ubiquitination, thus contributing to HCC development. This work provides a novel insight into HCC development and a potential therapeutic strategy for HCC patients.

In the Era of Systemic Therapy for Hepatocellular Carcinoma Is Transarterial Chemoembolization Still a Card to Play?

Conventional transarterial embolization (cTACE) has been proven to be effective for intermediate stage hepatocellular carcinoma (HCC), with a recent systematic review showing an overall survival (OS) of 19.4 months. Nevertheless, due to the rapid development of the systemic therapeutic landscape, the place of TACE is becoming questionable. Is there still a niche for TACE in the era of immunotherapy and combination treatments such as atezolizumab-bevacizumab, which has shown an OS of 19.2 months with excellent tolerance? The development of drug-eluting microspheres (DEMs) has led to the standardization of the technique, and along with adequate selection, it showed an OS of 48 months in a retrospective study. In order to increase treatment selectivity, new catheters have also been added to the TACE arsenal as well as the use of cone-beam CT (CBCT), which provides three-dimensional volumetric images and guidance during procedures. Moreover, the TACE indications have also widened. It may serve as a "bridging therapy" for liver transplantation candidates while they are on the waiting list, and it represents a valuable downstaging tool to transplantation criteria. The aim of this review is to explore the current data on the advancements of TACE and its future place amongst the growing panel of treatments.

Assessing locoregional treatment response to Hepatocellular Carcinoma: comparison of hepatobiliary contrast agents to extracellular contrast agents

Cross-sectional imaging with contrast-enhanced magnetic resonance imaging (MRI) is routinely performed in patients with hepatocellular carcinoma (HCC) to assess tumor response to locoregional therapy (LRT). Current response assessment algorithms, such as the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA), allow assessment using conventional gadolinium-based extracellular contrast agents (ECA) for accurate tumor response assessment following LRT. MRI with hepatobiliary agents (HBA) allows an acquisition of hepatobiliary phase (HBP), which is proven to increase sensitivity for detection of observations in at-risk patients, particularly for findings < 2 cm. The use of HBA is not yet incorporated into the TRA; however, it is increasingly used in clinical practice. Few published studies have evaluated the performance of LI-RADS TRA by applying ancillary features related to HBP that has resulted in category adjustment, enabling more sensitive and unequivocal diagnosis. This may help timely management of viable cases, without a significant loss of specificity in comparison with the ECA-based LI-RADS TRA assessment. In this review, we will describe and compare the imaging appearance of treated HCC on MRI using extracellular and hepatobiliary contrast agents and discuss emerging evidence and pitfalls in the assessment of tumor response following LRT with HBA.

Loco-regional hepatocellular carcinoma treatment services as a bridge to liver transplantation

BACKGROUND

Liver transplantation remains the main curative treatment option for hepatocellular carcinoma (HCC) patients. In the Eurotransplant area Milan criteria are used to assign priority extra points (exceptional MELD, exMELD) for patients on the waiting list. To prevent patients from tumor progression, loco-regional (neoadjuvant) treatment (LRT) is used. For patients unlikely to timely receive an organ via primary allocation, "extended critera donor (ECD) organs" are used. The present study aimed to investigate the survival after LT with a strategy of minimizing waiting list dropouts by using LRT for bridging and transplanting ECD organs if possible and necessary.

METHODS

Between October 2010 and May 2015, 50 liver transplants for HCC were included in this retrospective study. Of those, 42 (84%) met the Milan criteria according to the preoperative radiological examination. Forty-one patients (82%) received LRT. The waiting time was analyzed according to LRT. Kaplan-Meier curves with log-rank statistics were used for survival analyses.

RESULTS

One- and five-year overall survival within Milan criteria was 94.3% and 83.7% compared with 91.7% and 67.9% beyond Milan criteria, though statistical significance was not reached (P = 0.487). LRT had no impact on overall survival (P = 0.629). Median waiting time was shorter if no LRT was performed (4.6 months vs. 1.5 months, P = 0.006) and there were no cases of waiting list dropouts. Using ECD organs had no impact on overall survival (P = 0.663).

CONCLUSIONS

Patients with an expected waiting time to transplantation of >6 months could be successfully treated with LRT as a bridge to transplant. Overall and disease-free survival for patients within and beyond Milan criteria was comparable and the use of ECD organs in this cohort of HCC patients proved to be a safe option.

Efficacy of Radiofrequency Ablation versus Transarterial Chemoembolization for Patients with Solitary Hepatocellular Carcinoma ≤3 cm

Optimal treatment for small hepatocellular carcinoma (HCC) ≤ 3 cm remains controversial. Ablation and chemoembolization are considered for nonoperative candidates. This study compares survival among patients with solitary HCC ≤ 3 cm treated with radiofrequency ablation (RFA) and transarterial chemoembolization (TACE). Patients diagnosed with HCC ≤ 3 cm between 2005 and 2014 were included. Kaplan-Meier survival functions with log-rank tests were used to estimate recurrence-free survival and overall survival (OS) survival. Among 161 patients with solitary HCC ≤ 3 cm, 145 patients with mean age of 65.2 years (69.2) and 95 per cent prevalence of cirrhosis had operative treatment or TACE, and/or RFA. From this cohort, 27 (19%) patients had TACE, 27 (19%) patients had RFA, and 15 (10%) patients had TACE/RFA. The patients treated with definitive TACE, RFA, or TACE/RFA had a similar 1-year recurrence-free survival (23% vs 27% vs 36%, respectively, P = 0.445) and similar 5-year OS (21% vs 24% vs 33%, respectively, P = 0.287). Thirty-five (24%) patients were bridged to transplantation with TACE and/or RFA. The 5-year OS was significantly improved in patients bridged to transplantation (P < 0.001). Survival does not differ between patients with solitary HCC ≤ 3 cm treated with TACE or RFA. Patients who were bridged to transplantation had significantly greater OS compared with patients who were not transplanted.

Cost-effectiveness analysis of potentially curative and combination treatments for hepatocellular carcinoma with person-level data in a Canadian setting

Patients with early-stage hepatocellular carcinoma (HCC) are potential candidates for curative treatments such as radiofrequency ablation (RFA), surgical resection (SR), or liver transplantation (LT), which have demonstrated a significant survival benefit. We aimed to estimate the cost-effectiveness of curative and combination treatment strategies among patients diagnosed with HCC during 2002-2010. This study used Ontario Cancer Registry-linked administrative data to estimate effectiveness and costs (2013 USD) of the treatment strategies from the healthcare payer's perspective. Multiple imputation by logistic regression was used to handle missing data. A net benefit regression approach of baseline important covariates and propensity score adjustment were used to calculate incremental net benefit to generate incremental cost-effectiveness ratio (ICER) and uncertainty measures. Among 2,222 patients diagnosed with HCC, 10.5%, 14.1%, and 10.3% received RFA, SR, and LT monotherapy, respectively; 0.5-3.1% dual treatments; and 0.5% triple treatments. Compared with no treatment (53.2%), transarterial chemoembolization (TACE) + RFA (average $2,465, 95% CI: -$20,000-$36,600/quality-adjusted life years [QALY]) or RFA monotherapy ($15,553, 95% CI: $3,500-$28,500/QALY) appears to be the most cost-effective modality with lowest ICER value. The cost-effectiveness acceptability curve showed that if the relevant threshold was $50,000/QALY, RFA monotherapy and TACE+ RFA would have a cost-effectiveness probability of 100%. Strategies using LT delivered the most additional QALYs and became cost-effective at a threshold of $77,000/QALY. Our findings found that TACE+ RFA dual treatment or RFA monotherapy appears to be the most cost-effective curative treatment for patients with potential early stage of HCC in Ontario. These findings highlight the importance of identifying and measuring differential benefits, costs, and cost-effectiveness of alternative HCC curative treatments in order to evaluate whether they are providing good value for money in the real world.

Treatment Options in Patients Awaiting Liver Transplantation with Hepatocellular Carcinoma and Cholangiocarcinoma

Liver transplantation (LT) provides a good chance of cure for selected patients with hepatocellular carcinoma (HCC) and perihilar cholangiocarcinoma (pCCA). Patients with HCC on a waiting list for LT are at risk for tumor progression and dropout. Treatment of HCC with locoregional therapies may lessen dropout due to tumor progression. Strict selection and adherence to the LT criteria for patients with pCCA before and after neoadjuvant chemotherapy are critical for optimal outcome with LT. This article reviews the existing data for the various treatment strategies used for patients with HCC and pCCA awaiting LT.

No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers

Objective

To evaluate the in vivo technical feasibility, efficiency, and safety of switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) as a no-touch ablation technique in the porcine liver.

Materials and methods

The animal care and use committee approved this animal study and 16 pigs were used in two independent experiments. In the first experiment, RFA was performed on 2-cm tumor mimickers in the liver using a no-touch technique in the SM mode (2 groups, SM1: 10 minutes, n = 10; SM2: 15 minutes, n = 10) and SB-mode (1 group, SB: 10 minutes, n = 10). The technical success with sufficient safety margins, creation of confluent necrosis, ablation size, and distance between the electrode and ablation zone margin (DEM), were compared between groups. In the second experiment, thermal injury to the adjacent anatomic organs was compared between SM-RFA (15 minutes, n = 13) and SB-RFA modes (10 minutes, n = 13).

Results

The rates of the technical success and the creation of confluent necrosis were higher in the SB group than in the SM1 groups (100% vs. 60% and 90% vs. 40%, both p < 0.05). The ablation volume in the SM2 group was significantly larger than that in the SB group (59.2±18.7 cm³ vs. 39.8±9.7 cm^3,p < 0.05), and the DEM in the SM2 group was also larger than that in the SB group (1.39±0.21 cm vs. 1.07±0.10 cm, p < 0.05). In the second experiment, the incidence of thermal injury to the adjacent organs and tissues in the SB group (23.1%, 3/13) was significantly lower than that in the SM group (69.2%, 8/13) (p = 0.021).

Conclusion

SB-RFA was more advantageous for a no-touch technique for liver tumors, showing the potential of a better safety profile than SM-RFA.

New Developments in Orthotopic Liver Transplant for Hepatocellular Carcinoma

The use of orthotopic liver transplant for hepatocellular carcinoma was a major advance, pioneered by Thomas E. Starzl as a way to circumvent the limitations imposed on the liver surgeon by the presence of cirrhosis and liver failure. Patients with a few small tumors, whatever their degree of liver damage, may expect prolonged survival (70% at 5 years). Patients with more advanced tumors have high recurrence rates and more limited survival, possibly due to immune suppression or pretransplant understaging of their tumors. Another possibility is that patients with micrometastases have a longer survival time, during which the metastases eventually become evident. Recent advances include the identification of patients using levels of tumor markers to allow more careful patient selection with better outcomes. The contributions of molecular signatures and the new, effective antiviral agents are possibly significant.