Combination of interventional oncology local therapies and immunotherapy for the treatment of hepatocellular carcinoma

Current Status of Immunotherapy in Management of Small Bowel Neuroendocrine Tumors

PURPOSE OF REVIEW

This study aims to present the current landscape of immunotherapy in the management of small bowel neuroendocrine tumors and identify ongoing and future targets for improved response.

RECENT FINDINGS

Somatostatin analogs and mTOR inhibitors remain cornerstones of non-surgical treatment, and applications of PRRT in SBNET are promising. Several efforts to replicate the success of immunotherapies in other solid tumors have been attempted in SBNET, with limited responses observed with current immune targets, such as PD-1/PD-L1 and CTLA-4. Epigenetic analyses have suggested a potential role for methylation and histone acetylation in SBNET tumorigenesis that warrant greater exploration. While the incidence of SBNET continues to increase, the number of effective therapies is few. Further elucidation of targetable components of the SBNET immune microenvironment with greater modulatory effects is necessary to improve outcomes in this growing patient population.

Multidisciplinary approaches to downstaging hepatocellular carcinoma: present and future

Downstaging of hepatocellular carcinoma (HCC) is typically defined as the reduction in size or number of viable tumors through locoregional therapy (LRT), aiming to meet the established criteria for liver transplantation (LT). According to the Barcelona Clinic Liver Cancer (BCLC) staging system, a subgroup of patients with BCLC-B may benefit most from downstaging therapies. The United Network Organ Sharing downstaging protocol identifies potential candidates for downstaging by setting out 'inclusion criteria' and defining 'successful downstaging.' Additionally, the protocol considers factors related to tumor biology, such as an alphafetoprotein level <500 ng/mL after LRT. Reports indicate that successful downstaging rates following LRT are about 50%, with post- LT recurrence rates comparable to those of patients within the Milan criteria. A comprehensive multicenter US study on 10-year outcomes post-LT after downstaging showed 10-year post-LT survival and recurrence rates of 52.1% and 20.6%, respectively, for patients whose disease was downstaged; this compares to 61.5% and 13.3% for those consistently within the Milan criteria. Recently, the development of effective systemic treatments for HCC, such as immuno-oncologic agents, has provided additional opportunities for downstaging. Numerous clinical trials are exploring a multidisciplinary approach (MDA) combining LRT and systemic therapy. Although concrete evidence of the superiority of MDA for HCC downstaging is lacking, some retrospective studies and phase I and II trials have shown promising results regarding the efficacy and safety of MDA for this purpose. In this review, we will also discuss the future of MDA protocols in downstaging for improved clinical outcomes.

Application of combined ablation and immunotherapy in NSCLC and liver cancer: Current status and future prospects

This review examines combining tumor ablation therapy with immunotherapy for respiratory and digestive system tumors, particularly NSCLC and liver cancer. Despite advancements in traditional methods, they face limitations in advanced-stage tumors. Ablation techniques like RFA, MWA, and cryoablation offer minimally invasive options, while immune checkpoint inhibitors enhance the immune system's tumor-fighting ability. This review highlights their synergistic effects, clinical outcomes, and future research directions, including optimizing protocols, exploring new combinations, uncovering molecular mechanisms, advancing precision medicine, and improving accessibility. Combined therapy is expected to improve efficacy and patient outcomes significantly.

Second-Line Treatment after Failure of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: Tyrosine Kinase Inhibitor, Retrial of Immunotherapy, or Locoregional Therapy?

Background

Immune checkpoint inhibitor (ICI)-based therapy such as atezolizumab plus bevacizumab or durvalumab plus tremelimumab became mainstream first-line systemic treatment in advanced hepatocellular carcinoma (HCC) patients since remarkably superior efficacy of ICI-based therapy compared to tyrosine kinase inhibitors (TKIs) was reported in two recent randomized controlled trials (RCTs) (IMbrave150, HIMALAYA). However, the optimal second-line therapy after treatment failure of first-line ICI-based therapy remains unknown as no RCT has examined this issue.

Summary

Therefore, at present, most clinicians are empirically treating patients with TKIs or retrial of ICI or locoregional treatment (LRT) modality such as transarterial therapy, radiofrequency ablation, and radiation therapy in this clinical setting without solid evidence. In this review, we will discuss current optimal strategies for second-line treatment after the failure of first-line ICI-based therapy by reviewing published studies and ongoing prospective trials.

Key Messages

Clinicians should consider carefully whether to treat the patients with TKI, other ICI-based therapy, or LRT in this situation by considering several factors including liver function reserve, performance status, adverse events of previous therapy, and presence of lesion that can consider LRT such as oligoprogression and vascular invasion. In the meantime, we await the results of ongoing prospective trials to elucidate the best management options.

CT-guided high dose rate brachytherapy can induce multiple systemic proteins of proliferation and angiogenesis predicting outcome in HCC

BACKGROUND AND PURPOSE

To determine the potential prognostic value of proliferation and angiogenesis plasma proteins following CT-guided high dose rate brachytherapy (HDR-BT) of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

For this prospective study, HDR-BT (1 × 15 Gy) was administered to 24 HCC patients. Plasma was obtained and analyzed using an Olink proteomics Target-96 immuno-oncology-panel that included multiple markers of angiogenesis and proliferation. Fold-change (FC) ratios were calculated by comparing baseline and 48 h post HDR-BT paired samples. Patients were classified as responders (n = 12) if they had no local progression within 6 months or systemic progression within 2 years. Non-responders (n = 12) had recurrence within 6 months and/or tumor progression or extrahepatic disease within 2 years.

RESULTS

Proliferation marker EGF was significantly elevated in non-responders compared to responders (p = 0.0410) while FGF-2, HGF, and PlGF showed no significant differences. Angiogenesis markers Angiopoietin-1 and PDGF-B were likewise significantly elevated in non-responders compared to responders (p = 0.0171, p = 0.0462, respectively) while Angiopoietin-2, VEGF-A, and VEGFR-2 did not differ significantly. Kaplan-Meier analyses demonstrated significantly shorter time to systemic progression in patients with increased EGF and Angiopoietin-1 (p = 0.0185, both), but not in patients with one of the remaining proteins elevated (all p > 0.1). Pooled analysis for these 9 proteins showed significantly shorter time to systemic progression for FC ≥1.3 and ≥1.5 for at least 3 proteins elevated (p = 0.0415, p = 0.0193, respectively).

CONCLUSION

Increased plasma levels of EGF and Angiopoietin-1 after HDR-BT for HCC are associated with poor response and may therefore function as predictive biomarkers of outcome.

Complications of immunotherapy in advanced hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) are highly effective in cancer treatment. However, the risks associated with the treatment must be carefully balanced against the therapeutic benefits. Immune-related adverse events (irAEs) are generally unpredictable and may persist over an extended period. In this review, we analyzed common irAEs reported in highly cited original articles and systematic reviews. The prevalent adverse reactions include fatigue, pyrexia, rash, pruritus, diarrhea, decreased appetite, nausea, abdominal pain, constipation, hepatitis, and hypothyroidism. Therefore, it is crucial to conduct evaluations not only of gastrointestinal organs but also of cardiac, neurologic, endocrine (including the frequently affected thyroid), and ophthalmic systems before commencing ICIs. This review further explores commonly reported types of irAEs, specific irAEs associated with each ICI agent, rare yet potentially fatal irAEs, and available treatment options for managing them.

Reduced-Dose or Discontinuation of Bevacizumab Might Be Considered after Variceal Bleeding in Patients with Hepatocellular Carcinoma Receiving Atezolizumab/Bevacizumab: Case Reports

Background and Objectives: Variceal bleeding (VB) is the most concerning condition that is difficult to treat after atezolizumab/bevacizumab in patients with advanced hepatocellular carcinoma (HCC). Materials and Methods: We would like to introduce the cases of two patients who underwent bevacizumab reduction or discontinuation when VB occurred after atezolizumab/bevacizumab. Results: VB occurred in two patients who showed good tumor response after atezolizumab/bevacizumab treatment, and all VBs were successfully treated with endoscopic variceal ligations. In the first patient, VB did not occur as the tumor response decreased after a 50% reduction in bevacizumab. In the second patient, VB occurred again after a 50% bevacizumab reduction, so bevacizumab was discontinued and treatment with atezolizumab alone has been successfully maintained. Conclusions: Accordingly, we would like to suggest that considering bevacizumab dose reduction instead of changing to tyrosine kinase inhibitor may be a good clinical choice in atezolizumab/bevacizumab patients who develop VB.

Inducing the Abscopal Effect in Liver Cancer Treatment: The Impact of Microwave Ablation Power Levels and PD-1 Antibody Therapy

Microwave ablation (MWA) is an effective treatment for liver cancer (LC), but its impact on distant tumors remains to be fully elucidated. This study investigated the abscopal effects triggered by MWA treatment of LC, at different power levels and with or without combined immune checkpoint inhibition (ICI). We established a mouse model with bilateral subcutaneous LC and applied MWA of varied power levels to ablate the right-sided tumor, with or without immunotherapy. Left-sided tumor growth was monitored to assess the abscopal effect. Immune cell infiltration and distant tumor neovascularization were quantified via immunohistochemistry, revealing insights into the tumor microenvironment and neovascularization status. Th1- and Th2-type cytokine concentrations in peripheral blood were measured using ELISA to evaluate systemic immunological changes. It was found that MWA alone, especially at lower power, promoted distant tumor growth. On the contrary, combining high-power MWA with anti-programmed death (PD)-1 therapy promoted CD8+ T-cell infiltration, reduced regulatory T-cell infiltration, upregulated a Th1-type cytokine (TNF-α) in peripheral blood, and inhibited distant tumor growth. In summary, combining high-power MWA with ICI significantly enhances systemic antitumor immune responses and activates the abscopal effect, offering a facile and robust strategy for improving treatment outcomes.

The Current Evidence of Intensity-Modulated Radiotherapy for Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Intensity-modulated radiotherapy (IMRT), an advanced RT technique, is a considerable treatment option for hepatocellular carcinoma (HCC). However, the distinguishing features of IMRT for HCC have not yet been clearly defined. A systematic review was performed according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The PubMed/MedLine, Embase, Cochrane Library, Web of Science, and KoreaMed were used to screen eligible studies focusing on treatment outcomes after IMRT for HCC until 18 April 2023. A total of 1755 HCC patients receiving IMRT among 29 studies from 2009 to 2023 were selected for the meta-analysis. The median proportion of Barcelona Clinic Liver Cancer stage C was 100% (range: 38-100%). Nineteen studies used combined treatment. Pooled rates of response and 1-year local control were 58% (95% confidence interval [CI], 50-65%) and 84% (95% CI, 70-94%), respectively. The median overall survival (OS) was 13 months (range: 5-45 months), and pooled 1- and 3-year OS rates were 59% (95% CI, 52-66%), and 23% (95% CI, 14-33%), respectively. Pooled rates of classic radiation-induced liver disease (RILD), nonclassic RILD, and hepatic toxicity ≥ grade 3 were 2%, 4%, and 4%, respectively. Although most patients had advanced-stage HCC and combined treatment was commonly used, IMRT for HCC showed similar survival to existing RT modalities and relatively low severe toxicity.

Preclinical Development and Validation of Translational Temperature Sensitive Iodized Oil Emulsion Mediated Transcatheter Arterial Chemo-Immuno-Embolization for the Treatment of Hepatocellular Carcinoma

Herein a practical strategy for augmenting immune activation in transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) is presented. Pluronic F127 (PF127) is incorporated with Lipiodol (LPD) to achieve safe and effective delivery of therapeutic agents during transcatheter intra-arterial (IA) local delivery. Enhanced emulsion stability, IA infusion, embolic effect, safety, pharmacokinetics, and tumor response of Doxorubicin loaded PF127-LPD (Dox-PF127-LPD) for TACE in both in vitro and in vivo preclinical VX2 liver cancer rabbit model and N1S1 HCC rat model are demonstrated. Then, transcatheter arterial chemo-immuno-embolization (TACIE) combining TACE and local delivery of immune adjuvant (TLR9 agonist CpG oligodeoxynucleotide) is successfully performed using CpG-loaded Dox-PF127-LPD. Concurrent and safe local delivery of CpG and TACE during TACIE demonstrate leveraged TACE-induced immunogenic tumor microenvironment and augment systemic anti-tumor immunity in syngeneic N1S1 HCC rat model. Finally, the broad utility and enhanced therapeutic efficacy of TACIE are validated in the diethylnitrosamine-induced rat HCC model. TACIE using clinically established protocols and materials shall be a convenient and powerful therapeutic approach that can be translated to patients with HCC. The robust anti-cancer immunity and tumor regression of TACIE, along with its favorable safety profile, indicate its potential as a novel localized combination immunotherapy for HCC treatment.

Syngeneic N1-S1 Orthotopic Hepatocellular Carcinoma in Sprague Dawley Rat for the Development of Interventional Oncology-Based Immunotherapy: Survival Assay and Tumor Immune Microenvironment

Rodent HCC rat models provide advantages for interventional oncology (IO) based immunotherapy research compared to other established larger animal models or mice models. Rapid and predictable tumor growth and affordable costs permit the formation of a compelling preclinical model investigating novel IO catheter-directed therapies and local ablation therapies. Among orthotopic HCC models, the N1-S1 orthotopic HCC model has been involved in many research cases. Suboptimal tumor induction rates and potential spontaneous regression during tumor implantation procedures discouraged the use of the N1-S1 HCC model in IO-based immunotherapies. Here, N1-S1 HCC models were generated with a subcapsular implantation of two different number of N1-S1 cells using a mini-laporatomy. Tumor growth assay and immunological profiles which can preclinically evaluate the therapeutic efficacy of IO-based immunotherapy, were characterized. Finally, an N1-S1 HCC rat model generated with the proposed procedure demonstrated a representative immune suppressive HCC tumor environment without self-tumor regression. The optimized syngeneic N1-S1 HCC rat models represent an essential tool for pre-clinical evaluation of new IO immunotherapies for the treatment of HCC.