Immune activation underlies a sustained clinical response to Yttrium-90 radioembolisation in hepatocellular carcinoma

Locoregional therapies combined with immune checkpoint inhibitors for liver metastases

Immune checkpoint inhibitors (ICIs) have achieved remarkable success in clinical research and practice. Notably, liver metastasis is not sensitive to ICIs. Liver locoregional therapies can cause irreversible damage to tumor cells and release tumor antigens, thereby providing a rationale for immunotherapy treatments in liver metastasis. The combination therapy of ICIs with locoregional therapies is a promising option for patients with liver metastasis. Preclinical studies have demonstrated that combining ICIs with locoregional therapies produces a significantly synergistic anti-tumor effect. However, the current evidence for the efficacy of ICIs combined with locoregional therapies remains insufficient. Therefore, we review the literature on the mechanisms of locoregional therapies in treating liver metastasis and the clinical research progress of their combination with ICIs.

CCL2 Predicts Survival in Patients with Inoperable Hepatocellular Carcinoma Undergoing Selective Internal Radiotherapy

PURPOSE

Hepatocellular carcinoma (HCC) is the largest subgroup of primary liver tumors. Ablative therapies, such as selective internal radiation therapy (SIRT), are used in late stages for patients with unresectable liver metastases and no response to other therapies. CCL2 (C-C motif chemokine ligand 2) is a potent monocyte chemoattractant. It is associated with tumor progression and metastasis. The role of circulating CCL2 as a biomarker in HCC undergoing selective internal radiation therapy remains unclear.

METHODS

A total of 41 patients (8 female, 33 male) suffering from HCC and undergoing SIRT were enrolled. Pre- and post-therapy changes in circulating CCL2 levels were determined by bead-based immunoassay and compared with clinical laboratory parameters and patient data.

RESULTS

A total of 32 patients exhibited survival beyond 60 days. It was observed that levels of CCL2 correlated with scores indicating a higher likelihood of non-survival and with the severity of the disease. Moreover, a significant inverse correlation was discovered between CCL2 levels and the survival of patients over 60 days in relation to counts of leukocytes, granulocytes, monocytes, and C-reactive protein.

CONCLUSIONS

CCL2 may serve as a potential marker for patient survival after SIRT. The prediction of which HCC patients are likely to benefit from SIRT may be helpful in guiding therapeutic management.

Yttrium-90 Induces an Effector Memory Response with Neoantigen Clonotype Expansion: Implications for Immunotherapy

Yttrium-90 (90Y) transarterial radioembolization can safely and effectively treat hepatocellular carcinoma (HCC). Clinical trials combining 90Y with immunotherapy are aimed at improving treatment response rates. The impact of transient 90Y-induced lymphopenia on T-cell homeostasis and functional dynamics is unknown. Paired blood specimens were collected prior to first-cycle 90Y and at imaging follow-up in patients with HCC Barcelona Clinic Liver Cancer stages A-B. Flow cytometry and T-cell receptor (TCR) sequencing were used to monitor changes in T-cell subsets and TCR repertoire following 90Y. Objective response (OR) rates were determined using modified RECIST and defined as either OR or nonobjective response. Time-to-progression (TTP) was defined as progression to Barcelona Clinic Liver Cancer stage C within 6 months following 90Y. 90Y induced shifts in both CD4+ (P = 0.049) and CD8+ (P < 0.001) toward an effector memory T-cell response independent of treatment response rate. Nonresponders to 90Y were characterized by a sustained elevation in both naïve CD4+ cells (P = 0.019) and programmed cell death protein 1 expression in CD8+ cells (P = 0.003). Paired analysis of the TCR repertoire revealed a variable induction of neoantigen clonotypes and expansion of existing clonotypes independent of 90Y response. In patients with an OR, changes in TCR clonality did not influence TTP. However, polyclonal profiles in patients without an OR were associated with shorter TTP (P = 0.005; HR, 10.8) and 75% disease progression rates 6 months following treatment. 90Y induces a population shift from central to effector memory accompanied by neoantigen T-cell responses independent of treatment response rate. Monoclonal shifts in the post-90Y T-cell repertoire had superior overall TTP and improved TTP in patients with a first-cycle nonobjective response.

SIGNIFICANCE

90Y can safely treat HCC; however, it causes transient lymphopenia. In this article, 90Y stimulates a peripheral effector memory response independent of initial treatment response. TCR sequencing revealed that polyclonal profiles in patients without an OR to treatment were associated with rapid progression rates 6 months after 90Y.

The association between tumour heterogeneity and immune evasion mechanisms in hepatocellular carcinoma and its clinical implications

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. The emergence of combination therapy, atezolizumab (anti-PDL1, immune checkpoint inhibitor) and bevacizumab (anti-VEGF) has revolutionised the management of HCC. Despite this breakthrough, the best overall response rate with first-line systemic therapy is only about 30%, owing to intra-tumoural heterogeneity, complex tumour microenvironment and the lack of predictive biomarkers. Many groups have attempted to classify HCC based on the immune microenvironment and have consistently observed better outcomes in immunologically "hot" HCC. We summarised possible mechanisms of tumour immune evasion based on the latest literature and the rationale for combination/sequential therapy to improve treatment response. Lastly, we proposed future strategies and therapies to overcome HCC immune evasion to further improve treatment outcomes of HCC.

Immunotherapy for hepatocellular carcinoma: The next evolution in expanding access to liver transplantation

Immunotherapy has revolutionised the treatment of advanced hepatocellular carcinoma (HCC). In addition, several phase III trials of immunotherapy in combination with surgical or locoregional therapies for early-to intermediate-stage HCC have recently reported positive results, and other phase III trials in the same patient population are currently in progress. As the application of immunotherapy is shifting to include patients with earlier stages of HCC, one looming question now emerges: What is the role of immunotherapy in the pre-liver transplant population? Liver transplantation is a potentially curative therapy for HCC and confers the additional advantage of restoring a normal, healthy liver. In pre-transplant patients, immunotherapy may improve downstaging success and tumour control at the cost of some immunologic risks. These include immune-related toxicities, which are particularly relevant in a uniquely vulnerable population with chronic liver disease, and the possibility of acute rejection after transplantation. Ultimately, the goal of immunotherapy in this population will be to effectively expand access to liver transplantation while preserving pre- and post-transplant outcomes. In this review, we discuss the mechanisms supporting combination immunotherapy, summarise key recent clinical data from major immunotherapy trials, and explore how immunotherapy can be applied in the neoadjuvant setting prior to liver transplantation in selected high-risk patients.

Interventional radiology meets immuno-oncology for hepatocellular carcinoma

Locoregional and systemic therapies are the most used treatment options for patients with hepatocellular carcinoma (HCC). Interventional radiologists have improved and developed novel protocols and devices for both intratumoural ablative approaches with curative intent and various transarterial intrahepatic treatment options, which have continuously improved patient outcomes. Two large phase III randomised clinical trials have demonstrated the efficacy of different immune checkpoint inhibitors either as single agents or in combination in the first-line setting and immunotherapy has become the standard first-line treatment option for patients with advanced HCC. Herein, we discuss advances and perspectives in the area of interventional radiology (IR) and immune-oncology (IO). We summarise results from recent studies and provide an overview of ongoing studies in IR and IO. Based on the significant advances in both areas, we propose that IR and IO need to cover the emerging "discipline" of IR-IO, in which we develop and test novel approaches to combine locoregional therapies with immunotherapy, in order to develop sufficient evidence for them to be considered standard of care for patients with HCC in the near future.

Real-World Data on the Diagnosis, Treatment, and Management of Hepatocellular Carcinoma in the Asia-Pacific: The INSIGHT Study

Introduction

Hepatocellular carcinoma (HCC) is the sixth most commonly diagnosed cancer and the third leading cause of cancer death worldwide. While there has been rapid evolution in the treatment paradigm of HCC across the past decade, the extent to which these newly approved therapies are utilized in clinical practice in the real world is, however, unknown. The INSIGHT study was an investigator-initiated, multi-site longitudinal cohort study conducted to reflect real-world epidemiology and clinical practice in Asia-Pacific in the immediate 7-year period after the conclusion of the BRIDGE study.

Methods

Data were collected both retrospectively (planned 30% of the total cohort size) and prospectively (planned 70%) from January 2013 to December 2019 from eligible patients newly diagnosed with HCC from 33 participating sites across 9 Asia-Pacific countries.

Results

A total of 2,533 newly diagnosed HCC patients (1,052 in retrospective cohort and 1,481 in prospective cohort) were enrolled. The most common risk factor was hepatitis B in all countries except Japan, Australia, and New Zealand, where the prevalence of hepatitis C and diabetes were more common. The top three comorbidities reported in the INSIGHT study include cirrhosis, hypertension, and diabetes. We observe high heterogeneity in the first-line treatment recorded across countries and across disease stages, which significantly affects survival outcomes. Stratification by factors such as etiologies, tumor characteristics, the presence of extrahepatic metastases or macrovascular invasion, and the use of subsequent lines of treatment were performed.

Conclusion

The INSIGHT study describes a wide spectrum of clinical management practices in HCC, where patient demographics, differential costs, and patient access to therapies may lead to wide geographical variations through the patient's treatment cycle, from diagnosis to clinical outcome. The high heterogeneity in patient outcomes demonstrates the need for more robust and clinical management strategies to be designed and adopted to bring about better patient outcomes.

Radioembolization plus Immune Checkpoint Inhibitor Therapy Compared with Radioembolization plus Tyrosine Kinase Inhibitor Therapy for the Treatment of Hepatocellular Carcinoma

PURPOSE

To investigate if combination therapy with immune checkpoint inhibitor (ICI) and yttrium-90 (90Y) radioembolization results in superior outcomes than those yielded by tyrosine kinase inhibitor (TKI) therapy and 90Y for the treatment of intermediate- to advanced-stage hepatocellular carcinoma (HCC).

METHODS

A retrospective review of patients presented at an institutional multidisciplinary liver tumor board between January 1, 2012 and August 1, 2023 was conducted. In total, 44 patients with HCC who underwent 90Y 4 weeks within initiation of ICI or TKI therapy were included. Propensity score matching was conducted to account for baseline demographic differences. Kaplan-Meier analysis was used to compare median progression-free survival (PFS) and overall survival (OS), and univariate statistics identified disease response and control rate differences. Duration of imaging response was defined as number of months between the first scan after therapy and the first scan showing progression as defined by modified Response Evaluation Criteria in Solid Tumors (mRECIST) or immune Response Evaluation Criteria in Solid Tumors (iRECIST). Adverse events were analyzed per Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

RESULTS

Patients in the 90Y+ICI therapy group had better objective response rates (ORRs) (89.5% vs 36.8%; P < .001) and disease control rates (DCRs) (94.7% vs 63.2%; P < .001) by mRECIST and iRECIST (ORR: 78.9% vs 36.8%; P < .001; DCR: 94.7% vs 63.2%; P < .001). Median PFS (8.3 vs 4.1 months; P = .37) and OS (15.8 vs 14.3 months; P = .52) were not statistically different. Twelve patients (63.1%) in the 90Y+TKI group did not complete systemic therapy owing to adverse effects compared with 1 patient (5.3%) in the 90Y+ICI group (P < .001). Grade 3/4 adverse events were not statistically different (90Y+TKI: 21.1%; 90Y+ICI: 5.3%; P = .150).

CONCLUSIONS

Patients with HCC who received 90Y+ICI had better imaging response and fewer regimen-altering adverse events than those who received 90Y+TKI. No significant combination therapy adverse events were attributable to radioembolization.

Overcoming Resistance to Immune Checkpoint Blockade in Liver Cancer with Combination Therapy: Stronger Together?

Primary liver cancer, represented mainly by hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA), is one of the most common and deadliest tumors worldwide. While surgical resection or liver transplantation are the best option in early disease stages, these tumors often present in advanced stages and systemic treatment is required to improve survival time. The emergence of immune checkpoint inhibitor (ICI) therapy has had a positive impact especially on the treatment of advanced cancers, thereby establishing immunotherapy as part of first-line treatment in HCC and CCA. Nevertheless, low response rates reflect on the usually cold or immunosuppressed tumor microenvironment of primary liver cancer. In this review, we aim to summarize mechanisms of resistance leading to tumor immune escape with a special focus on the composition of tumor microenvironment in both HCC and CCA, also reflecting on recent important developments in ICI combination therapy. Furthermore, we discuss how combination of ICIs with established primary liver cancer treatments (e.g. multikinase inhibitors and chemotherapy) as well as more complex combinations with state-of-the-art therapeutic concepts may reshape the tumor microenvironment, leading to higher response rates and long-lasting antitumor immunity for primary liver cancer patients.

New insights into mechanisms and interventions of locoregional therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is responsible for a significant number of cancer-related deaths worldwide and its incidence is increasing. Locoregional treatments, which are precision procedures guided by imaging to specifically target liver tumors, play a critical role in the management of a substantial portion of HCC cases. These therapies have become an essential element of the HCC treatment landscape, with transarterial chemoembolization (TACE) being the treatment of choice for patients with intermediate to advanced stages of the disease. Other locoregional therapies, like radiofrequency ablation, are highly effective for small, early-stage HCC. Nevertheless, the advent of targeted immunotherapy has challenged these established treatments. Tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) have shown remarkable efficacy in clinical settings. However, their specific uses and the development of resistance in subsequent treatments have led clinicians to reevaluate the future direction of HCC therapy. This review concentrates on the distinct features of both systemic and novel locoregional therapies. We investigate their effects on the tumor microenvironment at the molecular level and discuss how targeted immunotherapy can be effectively integrated with locoregional therapies. We also examine research findings from retrospective studies and randomized controlled trials on various combined treatment regimens, assessing their validity to determine the future evolution of locoregional therapies within the framework of personalized, comprehensive treatment.

A Pilot Study of Pembrolizumab in Combination With Y90 Radioembolization in Subjects With Poor Prognosis Hepatocellular Carcinoma

BACKGROUND

Combination checkpoint inhibition therapy with yttrium-90 (Y90) radioembolization represents an emerging area of interest in the treatment of advanced hepatocellular carcinoma (HCC). HCRN GI15-225 is an open-label, single-arm multicenter, pilot study (NCT03099564).

METHODS

Eligible patients had poor prognosis, localized HCC defined as having portal vein thrombus, multifocal disease, and/or diffuse disease that were not eligible for liver transplant or surgical resection. Patients received pembrolizumab 200 mg intravenously every 3 weeks in conjunction with glass yttrium-90 (Y90) radioembolization TheraSphere. Primary endpoint was 6-month progression-free survival (PFS6) per RECIST 1.1. Secondary endpoints included time to progression (TTP), objective response rate (ORR), overall survival (OS), and safety/tolerability.

RESULTS

Between October 23, 2017 and November 24, 2020, 29 patients were enrolled: 2 were excluded per protocol. Fifteen of the remaining 27 patients were free of progression at 6 months (55.6%; 95% CI, 35.3-74.5) with median PFS 9.95 months (95% CI, 4.14-15.24) and OS 27.30 months (95% CI, 10.15-39.52). One patient was not evaluable for response due to death; among the remaining 26 patients, ORR was 30.8% (95% CI, 14.3-51.8) and DCR was 84.6% (95% CI, 65.1-95.6).

CONCLUSION

In patients with localized, poor prognosis HCC, pembrolizumab in addition to glass Y90 radioembolization demonstrated promising efficacy and safety consistent with prior observations (ClinicalTrials.gov Identifier: NCT03099564; IRB Approved: 16-3255 approved July 12, 2016).

Expanding the Boundaries for Liver Transplantation for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which was the third most common cause of cancer death worldwide in 2020. Transplantation remains the preferred treatment for cure in otherwise unresectable HCC. There are several areas of active research that have led to expansion of eligibility criteria for transplantation including local-regional therapy for downstaging patients presenting outside of the Milan criteria and identification of tumor biomarkers aiding in the early diagnosis, determining prognosis and likelihood of recurrence after transplantation for HCC. New neoadjuvant therapies and post-transplant immunosuppression regimens may also result in expansion of transplant eligibility criteria for HCC.

Long-Term Overall Survival After Selective Internal Radiation Therapy for Locally Advanced Hepatocellular Carcinomas: Updated Analysis of DOSISPHERE-01 Trial

Interim analysis of the DOSISPHERE-01 study demonstrated a strong improvement in response and overall survival (OS) on using 90Y-loaded glass microspheres with personalized dosimetry compared with standard dosimetry in patients with nonoperable locally advanced hepatocellular carcinoma. This report sought to provide a long-term analysis of OS. Methods: In this phase II study (ClinicalTrials.gov identifier NCT02582034), treatment was randomly assigned (1:1) with the goal to deliver either at least 205 Gy (if possible >250-300 Gy) to the index lesion in the personalized dosimetry approach (PDA) or 120 ± 20 Gy to the treated volume in the standard dosimetry approach (SDA). The 3-mo response of the index lesion was the primary endpoint, with OS being one of the secondary endpoints. This report is a post hoc long-term analysis of OS. Results: Overall, 60 hepatocellular carcinoma patients with at least 1 lesion larger than 7 cm and more than 30% of hepatic reserve were randomized (intent-to-treat population: PDA, n = 31; SDA, n = 29), with 56 actually treated (modified intent-to-treat population: n = 28 in each arm). The median follow-up for long-term analysis was 65.8 mo (range, 2.1-73.1 mo). Median OS was 24.8 mo and 10.7 mo (hazard ratio [HR], 0.51; 95% CI, 0.29-0.9; P = 0.02) for PDA and SDA, respectively, in the modified intent-to-treat population. Median OS was 22.9 mo for patients with a tumor dose of at least 205 Gy, versus 10.3 mo for those with a tumor dose of less than 205 Gy (HR, 0.42; 95% CI, 0.22-0.81; P = 0.0095), and was 22.9 mo for patients with a perfused liver dose of 150 Gy or higher, versus 10.3 mo for those with a perfused liver dose of less than 150 Gy (HR, 0.42; 95% CI, 0.23-0.75; P = 0.0033). Lastly, median OS was not reached in patients who were secondarily resected (n = 11, 10 in the PDA group and 1 in the SDA group), versus 10.8 mo in those without secondary resection (n = 45) (HR, 0.17; 95% CI, 0.065-0.43; P = 0.0002). Only resected patients displayed favorable long-term OS rates, meaning an OS of more than 50% at 5 y. Conclusion: After longer follow-up, personalized dosimetry sustained a meaningful improvement in OS, which was dramatically improved for patients who were accurately downstaged toward resection, including most portal vein thrombosis patients.

90Y-/166Ho- 'Radiation lobectomy' for liver tumors induces abnormal morphology and impaired drainage of peritumor lymphatics

Background & Aims

High-dose unilobar radioembolization, or 'radiation lobectomy' (RL), is an induction therapy that achieves contralateral future liver remnant hypertrophy while simultaneously irradiating the tumor. As such, it may prevent further growth, but it is unknown whether RL affects intrahepatic lymphatics, a major route via which liver tumors disseminate.

Methods

This was a case-control study conducted at University Medical Center Utrecht. The study compared lymph vessels in livers that had undergone RL (cases) with those in livers that had not undergone RL (controls). Histological samples were acquired from patients diagnosed with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) between 2017 and 2022. Lymph vessel morphology was analyzed by two researchers using podoplanin, a protein that is expressed in lymphatic endothelium. In vivo liver lymph drainage of radioembolized livers was assessed using intraoperative liver lymphangiography (ILL): during liver surgery, patent blue dye was injected into the liver parenchyma, followed by inspection for staining of perihepatic lymph structures. ILL results were compared to a previously published cohort.

Results

Immunohistochemical analysis on post-RL tumor tissues from ten patients with CRLM and nine patients with HCC revealed aberrant morphology of irradiated liver lymphatics when compared to controls (n = 3 per group). Irradiated lymphatics were tortuous (p <0.05), thickened (p <0.05) and discontinuous (p <0.05). Moreover, post-RL lymphatics had larger lumens (1.5-1.7x, p <0.0001), indicating lymph stasis. ILL revealed diminished lymphatic drainage to perihepatic lymph nodes and vessels in irradiated livers when compared to non-radioembolized controls (p = 1.0x10-4).

Conclusions

Radioembolization impairs peritumoral lymph vessel function. Further research is needed to evaluate if radioembolization impairs tumor dissemination via this route.

Impact and implications

Unilobar radioembolization can serve as an alternative to portal venous embolization for patients who are considered unresectable due to an insufficient future liver remnant. This research suggests that radioembolization impairs the function of peritumoral liver lymph vessels, potentially hindering dissemination via this route. These findings provide support for considering unilobar radioembolization over standard portal venous embolization.

Immune Effects of Intra-Arterial Liver-Directed Therapies

Image-guided intra-arterial locoregional therapies (LRTs) such as transarterial embolization, transarterial chemoembolization, and transarterial radioembolization exhibit effects on the immune system. Understanding the humoral (cytokine, chemokine, and growth factor) and cellular (T cell, neutrophil, dendritic cell, and macrophage) mechanisms underlying the immune effects of LRT is crucial to designing rational and effective combinations of immunotherapy and interventional radiology procedures. This article aims to review the immune effects of intra-arterial LRTs and provide insight into strategies to combine LRTs with systemic immunotherapy.

Modeling the Synergistic Impact of Yttrium 90 Radioembolization and Immune Checkpoint Inhibitors on Hepatocellular Carcinoma

The impact of yttrium 90 radioembolization (Y90-RE) in combination with immune checkpoint inhibitors (ICIs) has recently gained attention. However, it is unclear how sequencing and dosage affect therapeutic efficacy. The purpose of this study was to develop a mathematical model to simulate the synergistic effects of Y90-RE and ICI combination therapy and find the optimal treatment sequences and dosages. We generated a hypothetical patient cohort and conducted simulations to apply different treatments to the same patient. The compartment of models is described with ordinary differential equations (ODEs), which represent targeted tumors, non-targeted tumors, and lymphocytes. We considered Y90-RE as a local treatment and ICIs as a systemic treatment. The model simulations show that Y90-RE and ICIs administered simultaneously yield greater benefits than subsequent sequential therapy. In addition, applying Y90-RE before ICIs has more benefits than applying ICIs before Y90-RE. Moreover, we also observed that the median PFS increased up to 31~36 months, and the DM rates at 3 years decreased up to 36~48% as the dosage of the two drugs increased (p < 0.05). The proposed model predicts a significant benefit of Y90-RE with ICIs from the results of the reduced irradiated tumor burden and the associated immune activation and suppression. Our model is expected to help optimize complex strategies and predict the efficacy of clinical trials for HCC patients.

First-Line Treatment for Advanced Hepatocellular Carcinoma: A Three-Armed Real-World Comparison

Background and Aim

There are several existing systemic 1st- line therapies for advanced hepatocellular carcinoma (HCC), including atezolizumab/bevacizumab (Atez/Bev), sorafenib and lenvatinib. This study aims to compare the effectiveness of these three 1st-line systemic treatments in a real-world setting for HCC, focusing on specific patient subgroups analysis.

Methods

A total of 177 patients with advanced HCC treated with Atez/Bev (n = 38), lenvatinib (n = 21) or sorafenib (n = 118) as 1st line systemic therapy were retrospectively analyzed and compared. Primary endpoints included objective response rate (ORR), progression-free survival (PFS) and 15-month overall survival (15-mo OS). Subgroups regarding liver function, etiology, previous therapy and toxicity were analyzed.

Results

Atez/Bev demonstrated significantly longer median 15-month OS with 15.03 months compared to sorafenib with 9.43 months (p = 0.04) and lenvatinib with 8.93 months (p = 0.05). Similarly, it had highest ORR of 31.6% and longest median PFS with 7.97 months, independent of etiology. However, significantly superiority was observed only compared to sorafenib (ORR: 4.2% (p < 0.001); PFS: 4.57 months (p = 0.03)), but not comparing to lenvatinib (ORR: 28.6% (p = 0.87); PFS: 3.77 months (p = 0.10)). Atez/Bev also resulted in the longest PFS in patients with Child-Pugh A and ALBI 1 score and interestingly in those previously treated with SIRT. Contrary, sorafenib was non inferior in patients with impaired liver function.

Conclusion

Atez/Bev achieved longest median PFS and 15-mo OS independent of etiology and particularly in patients with stable liver function or prior SIRT treatment. Regarding therapy response lenvatinib was non-inferior to Atez/Bev. Finally, sorafenib seemed to perform best for patients with deteriorated liver function.

Recent advances in the management of hepatocellular carcinoma

Liver cancer remains a challenge of global health, being the 4th leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and is usually precipitated by chronic viral infections (hepatitis B and C), non-alcoholic steatohepatitis, heavy alcohol use, and other factors which may lead to chronic inflammation and cirrhosis of the liver. There have been significant advances in the systemic treatment options for HCC over the past decades, with several approvals of both immune checkpoint inhibitors and tyrosine kinase inhibitors in patients with preserved liver function. These advances have led to improvement in survival outcomes, with expected survival of greater than 18 months, in those with sensitive tumors, adequate liver function, and those functionally fit to receive sequential therapies. Several ongoing and promising trials are now evaluating combinational strategies with novel systemic agents and combinations of systemic therapy with locoregional therapy. In view of these trials, further advances in the treatment of HCC are foreseen in the near future.

Lineage-specific regulation of PD-1 expression in early-stage hepatocellular carcinoma following 90yttrium transarterial radioembolization - Implications in treatment outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related deaths in the world. Liver-directed therapies, including 90Yttrium (90Y) radioembolization, play an integral role in the management of HCC with excellent response rates. This has led to clinical trials of immunotherapy in combination with 90Y. Elevated PD-1 expression and lymphopenia were recently shown as risk factors for disease progression in early-stage HCC treated with liver-directed therapies. The aim of this study was to investigate PD-1 expression dynamics in bridge/downstage to transplant in HCC patients receiving first-cycle 90Y and evaluate the impact of these changes on response rates and time-to-progression (TTP).

METHODS

Patients with HCC receiving first-cycle 90Y as a bridge to liver transplantation (n = 99) were prospectively enrolled. Blood specimens were collected before 90Y and again during routine imagining follow-up to analyze PD-1 expression via flow cytometry. Complete and objective response rates (CR and ORR) were determined using mRECIST.

RESULTS

In 84/88 patients with available follow-up imaging, 83% had a localized ORR with 63% having localized CR. For overall response, 71% and 54% experienced ORR and CR, respectively. Post-90Y PD-1 upregulation in CD8 + associated with HCC progression and decreased TTP. Treatment with 90Y was associated with an anticipated significant post-treatment drop in lymphocytes (P < 0.001) that was independent of PD-1 expression for either CD4+ or CD8+ T cells (P = 0.751 and P = 0.375) and not associated with TTP risk. The change in lymphocytes was not correlated with PD-1 expression following treatment nor TTP.

CONCLUSIONS

Elevated PD-1 expression on peripheral T cells is associated with increased risk of HCC progression and shorter time to progression in bridging/downstaging to transplant HCC patients undergoing first-cycle 90Y. Treatment-induced lymphopenia was not associated with treatment response, or increased progression risk, suggesting this anticipated adverse event does not impact short-term HCC outcomes.

Downstaging Hepatocellular Carcinoma before Transplantation: Role of Immunotherapy Versus Locoregional Approaches

Hepatocellular carcinoma (HCC) continues to be a leading cause of cancer-related death in the United States. With advances in locoregional therapy for unresectable HCC during the last 2 decades and the recent expansion of transplant criteria for HCC, as well as ongoing organ shortages, patients are spending more time on the waitlist, which has resulted in an increased usage of locoregional therapies. The plethora of molecularly targeted therapies and immune checkpoint inhibitors under investigation represent the new horizon of treatment of HCC not only in advanced stages but also potentially at every stage of diagnosis and management.

Immunotherapy and Transarterial Radioembolization Combination Treatment for Advanced Hepatocellular Carcinoma

INTRODUCTION

The efficacy and safety of combined immunotherapy and transarterial radioembolization (TARE) were suggested in preclinical and early-phase trials, but these were limited by small sample sizes. We sought to compare the efficacy of combined therapy and immunotherapy alone in patients with advanced hepatocellular carcinoma (HCC).

METHODS

The National Cancer Database was used to identify patients with advanced HCC diagnosed between January 1, 2017, and December 31, 2019. We included patients who received combined therapy or immunotherapy alone as first-line treatment. Multivariable logistic regression was conducted to determine predictors of combined therapy. Kaplan-Meier and Cox regression approaches were used to identify predictors of overall survival and to compare hazards of mortality between the patients who received combined therapy and immunotherapy alone.

RESULTS

Of 1,664 eligible patients with advanced-stage HCC, 142 received combined TARE/immunotherapy and 1,522 received immunotherapy alone. Receipt of combination therapy was associated with care at an academic center and inversely associated with racial/ethnic minority status (Hispanic and Black individuals). The median overall survival was significantly higher in the combination group than in the immunotherapy alone group (19.8 vs 9.5 months). In multivariable analysis, combined therapy was independently associated with reduced mortality (adjusted hazard ratio 0.50, 95% confidence interval: 0.36-0.68, P < 0.001). Results were consistent across subgroups and in sensitivity analyses using propensity score matching and inverse probability of treatment weighting.

DISCUSSION

The combination of TARE and immunotherapy was associated with improved survival compared with immunotherapy alone in patients with advanced-stage HCC. Our findings underly the importance of large clinical trials evaluating combination therapy in these patients.

The progress of research on immune checkpoint inhibitor resistance and reversal strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in humans, which is prone to recurrence and metastasis and has a poor prognosis. The occurrence and progression of HCC are closely related to immune elimination, immune homeostasis, and immune escape of the immune system. In recent years, immunotherapy, represented by immune checkpoint inhibitors (ICIs), has shown powerful anti-tumor capabilities in HCC patients. However, there are still some HCC patients who cannot benefit from ICIs treatment due to their innate or acquired drug resistance. Therefore, it is of great practical significance to explore the possible mechanisms of resistance to ICIs in HCC and to use them as a target to design strategies to reverse resistance, to overcome drug resistance in HCC and to improve the prognosis of patients. This article summarizes the possible primary (tumor microenvironment alteration, and signaling pathways, etc.) and acquired (immune checkpoint upregulation) resistance mechanisms in patients with HCC treated with ICIs, and based on this, discusses the status and effectiveness of combination drug strategy to reverse drug resistance, to provide a reference for subsequent related studies and decisions.

Liver-Directed Therapy Combined with Systemic Therapy: Current Status and Future Directions

In the past several decades, major advances in both systemic and locoregional therapies have been made for many cancer patients. This has led to modern cancer treatment algorithms frequently calling for active interventions by multiple subspecialists at the same time. One of the areas where this can be clearly seen is the concomitant use of locoregional and systemic therapies in patients with primary or secondary cancers of the liver. These combined algorithms have gained favor over the last decade and are largely focused on the allure of the combined ability to control systemic disease while at the same time addressing refractory/resistant clonal populations. While the general concept has gained favor and is likely to only increase in popularity with the continued establishment of viable immunotherapy treatments, for many patients questions remain. Lingering concerns over the increase in toxicity when combining treatment methods, patient selection, and sequencing remain for multiple cancer patient populations. While further work remains, some of these questions have been addressed in the literature. This article reviews the available data on three commonly treated primary and secondary cancers of the liver, namely, hepatocellular carcinoma, cholangiocarcinoma, and metastatic colorectal cancer. Furthermore, strengths and weaknesses are reviewed and future directions are discussed.

Post-therapeutic microRNA-146a in liquid biopsies may determine prognosis in metastatic gastrointestinal cancer patients receiving 90Y-radioembolization

PURPOSE

The role of microRNA-146a (miR-146a) in defining the tumor immune microenvironment (TIME) is well established. The aim of this study was to evaluate circulating miR-146a as an early prognostic marker of 90Y-radioembolization (90Y-RE) in metastatic liver cancer and to assess the correlation between circulating miR-146a and TIME cellular composition in distant, yet untreated metastases.

METHODS

Twenty-one patients with bilobar liver lesions from gastro-intestinal cancer underwent lobar 90Y-RE. Biopsy of contralateral lobe abscopal tumors was acquired at the onset of a second treatment session at a median of 21 days after initial RE, immediately prior to ablation therapy of the contralateral lobe tumor. miR-146a was measured by RT-qPCR in plasma collected 24 h before (T1) and 48 h after (T2) initial unilobar 90Y-RE. The level of miR-146a was correlated with the infiltration of CD4 + , CD8 + , FoxP3 T cells, CD163 + M2 macrophages and immune-exhausted T cells in the abscopal tumor tissue acquired before the second treatment session.

RESULTS

Plasma samples collected at T2 showed a higher concentration of miR-146a with respect to T1 in 43% of the patients (p = 0.002). In these patients, tumors revealed a pro-tumorigenic immune composition with enrichment of Tim3 + immune exhausted cells (p = 0.021), in combination with a higher infiltration of CD163 + M2 macrophages and a lower infiltration of CD8 + T cells. Patients with a higher level of miR-146a after 90Y-RE showed a trend to shorter OS (p = 0.055).

CONCLUSION

miR-146a may represent a novel prognostic biomarker for 90Y-radioembolization in metastatic liver cancer.

Current status of yttrium-90 microspheres radioembolization in primary and metastatic liver cancer

Liver malignancy, including primary liver cancer and metastatic liver cancer, has become one of the most common causes of cancer-related death worldwide due to the high malignant degree and limited systematic treatment strategy. Radioembolization with yttrium-90 (90Y)-loaded microspheres is a relatively novel technology that has made significant progress in the local treatment of liver malignancy. The different steps in the extensive work-up of radioembolization for patients with an indication for treatment with 90Y microspheres, from patient selection to follow up, both technically and clinically, are discussed in this paper. It describes the application and development of 90Y microspheres in the treatment of liver cancer.

Colorectal liver metastases that survive radioembolization display features of aggressive tumor behavior

BACKGROUND

Radiation lobectomy is a therapeutic approach that involves targeted radiation delivery to induce future liver remnant hypertrophy and tumor control. In patients with colorectal liver metastases, only 30-40% have complete tumor regression. The importance of tumor biology in treatment response remains elusive.

METHODS

Patients with colorectal liver metastases who received radiation lobectomy were selected from surgical pathology files. Using a machine learning scoring protocol, pathological response was correlated to tumor absorbed dose and expression of markers of radioresistance Ki-67 (proliferation), CAIX (hypoxia), Olfm4 (cancer stem cells) and CD45 (leukocytes).

RESULTS

No linear association was found between tumor dose and response (ρ < 0.1, P = 0.73 (90Y), P = 0.92 (166Ho)). Response did correlate with proliferation (ρ = 0.56, P = 0.012), and non-responsive lesions had large pools (>15%) of Olfm4 positive cancer stem cells (Fisher's exact test, P = 0.0037). Responding lesions (regression grade ≤2) were highly hypoxic compared to moderate and non-responding lesions (P = 0.011). Non-responsive lesions had more tumor-infiltrating leukocytes (3240 cells/mm2 versus 650 cells/mm2), although this difference was not significant (P = 0.08).

CONCLUSION

The aggressive phenotype of a subset of surviving cancer cells emphasizes the importance of prompt resection after radiation lobectomy.

Update of latest data for combined therapy for esophageal cancer using radiotherapy and immunotherapy: A focus on efficacy, safety, and biomarkers

Esophageal cancer usually has a poor prognosis. Given the significant breakthrough with tumor immunotherapy, an increasing number of clinical studies have demonstrated that the combination of radiotherapy and immune checkpoint inhibitors (ICIs) may have a synergistic effect and good outcome in esophageal cancer. Clinical studies of immunoradiotherapy (iRT) for esophageal cancer have proliferated enormously from 2021 to the present. However, a summary of the efficacy and toxicity of combined therapy to guide esophageal cancer treatment in clinical practice is lacking. For this review, we integrate the latest data to analyze and assess the efficacy and safety of iRT for esophageal cancer. In addition, we discuss better predictive biomarkers, therapeutic options for specific populations, and other challenges to identify directions for future research design.

Impact of Low Skeletal Muscle Mass on Long-Term Outcomes in Hepatocellular Carcinoma Treated with Trans-Arterial Radioembolization: A Retrospective Multi-Center Study

Trans-arterial radioembolization (TARE) is a form of radiation therapy performed for hepatocellular carcinoma (HCC) via selective intra-arterial injection of Yttrium-90-loaded microspheres. This was a multi-center retrospective study of consecutive patients with HCC who underwent TARE between July 2009 and May 2019. Using pre-treatment computed tomography imaging, the total cross-sectional area (cm2) of the abdominal skeletal muscle at the third lumbar vertebra was measured. The skeletal muscle index (SMI) was calculated by normalizing the muscle area to patient height. In total, 347 patients (median age, 65 years; 284 male) were included in the study. A total of 108 (31.1%) patients had portal vein tumor thrombus (PVTT), and 126 (36.3%) were classified as LSMM. The median overall survival (OS) was 28.1 months (95% CI, 24.8-35.7), and median progression-free survival was 8.0 months (95% CI, 6.4-9.4). Multivariate Cox regression analysis revealed that LSMM (hazard ratio [HR], 1.36; 95% CI, 1.00-1.85, p = 0.05), PVTT (HR, 1.82; 95% CI, 1.33-2.49, p < 0.01), alpha-fetoprotein (AFP) (≥200 ng/mL) (HR 1.41; 95% CI, 1.04-1.92, p = 0.03), and albumin-bilirubin grade (2-3) (HR 1.74; 95% CI, 1.24-2.43, p < 0.01) were independently associated with poor OS. TARE provided favorable long-term outcomes for patients with advanced HCC. Pre-treatment LSMM independently associated with survival, suggesting its utility as a surrogate biomarker for identifying TARE candidates.

Combination Therapy of Immune Checkpoint Inhibitors with Locoregional Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is estimated to be the fourth leading cause of cancer-related deaths globally, and its overall prognosis is dismal because most cases are diagnosed at a late stage and are unamenable to curative treatment. The emergence of immune checkpoint inhibitors (ICIs) has dramatically improved the therapeutic efficacy for advanced hepatocellular carcinoma; however, their response rates remain unsatisfactory, partly because >50% of HCC exhibit an ICI-nonresponsive tumor microenvironment characterized by a paucity of cytotoxic T cells (immune-cold), as well as difficulty in their infiltration into tumor sites (immune excluded). To overcome this limitation, combination therapies with locoregional therapies, including ablation, transarterial embolization, and radiotherapy, which are usually used for early stage HCCs, have been actively explored to enhance ICI efficacy by promoting the release of tumor-associated antigens and cytokines, and eventually accelerating the so-called cancer-immunity cycle. Various combination therapies have been investigated in early- to late-phase clinical trials, and some have shown promising results. This comprehensive article provides an overview of the immune landscape for HCC to understand ICI efficacy and its limitations and, subsequently, reviews the status of combinatorial therapies of ICIs with locoregional therapy for HCC.

A Phase I/IIa Trial of Yttrium-90 Radioembolization in Combination with Durvalumab for Locally Advanced Unresectable Hepatocellular Carcinoma

PURPOSE

Synergistic effect of radiotherapy and immunotherapy for the treatment of hepatocellular carcinoma (HCC) has been reported. This phase I/IIa pilot trial evaluated preliminary efficacy and safety of combination of radioembolization with yttrium-90 microspheres (Y90-radioembolization) and durvalumab in patients with locally advanced unresectable HCC.

PATIENTS AND METHODS

Patients with Child-Pugh score ≤ 7 and locally advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B HCC or BCLC-C disease without extrahepatic metastases, received Y90-radioembolization followed by intravenous durvalumab 1,500 mg 7 to 14 days after Y90-radioembolization and every 4 weeks thereafter. Primary endpoint was time to progression (TTP) assessed by modified RECIST (mRECIST). Secondary endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR) determined by mRECIST, and safety.

RESULTS

All 24 patients enrolled received Y90-radioembolization and 23 received at least one dose of durvalumab. Median follow-up duration was 19.0 months (range, 2.2-24.2). Median TTP was 15.2 months [95% confidence interval (CI), 6.1-not estimated]. Median OS was not reached and 18-month OS rate was 58.3% (95% CI, 36.4-75.0). Median PFS was 6.9 months (95% CI, 5.4-15.2). Seven (29.2%) patients had a complete response and 13 (54.2%) had a partial response; ORR was 83.3% (95% CI, 62.6-95.3). Eleven (47.8%) patients experienced any-grade treatment-related adverse events. Two (8.7%) patients had grade 3 treatment-related adverse events (neutropenia and fever). None experienced any treatment-related serious adverse events.

CONCLUSIONS

In patients with locally advanced unresectable HCC, the combination of Y90-radioembolization and durvalumab demonstrated promising efficacy and safety, warranting further evaluation in large-scale controlled trials.

Selective Internal Radiotherapy Alters the Profiles of Systemic Extracellular Vesicles in Hepatocellular Carcinoma

Incidence of hepatocellular carcinoma (HCC) is increasing globally. Radioembolization (RE)/selective internal radiotherapy (SIRT) is a promising treatment for inoperable HCC. RE triggers an immune response, involving extracellular vesicles (EVs) which are crucial for cell communication and tumor development. This study explores EV immune profiles and origins in patients with inoperable HCC before and after SIRT/RE. Blood samples from 50 HCC-patients treated with SIRT/RE were collected before and after therapy to determine cytokines and isolate EVs using size exclusion chromatography. The dynamic range and EV quality required for detecting variations in surface markers were assessed. Thirty-seven EV surface markers were analyzed using flow cytometry and correlated with clinical parameters. Several immunological markers (CD4, CD2, CD40, CD45, CD49e, CD69, CD209-EVs) were present in the circulation of HCC patients. These markers positively correlated with therapy response and survival. Conversely, B cell CD20, endothelial cell CD146, platelet CD49e, and CD41b EV markers negatively correlated with 60-day survival. Elevated levels of IL-6 and IL-8 before therapy correlated negatively with patient survival, coinciding with a positive correlation with CD20-positive EVs. Plasma EVs from HCC patients exhibit immunological, cancer, and coagulation markers, including potential biomarkers (CD4, CD20, CD49e, CD146). These may enhance our understanding of cancer biology and facilitate SIRT therapy monitoring.

Multimodal molecular landscape of response to Y90-resin microsphere radioembolization followed by nivolumab for advanced hepatocellular carcinoma

BACKGROUND

Combination therapy with radioembolization (yttrium-90)-resin microspheres) followed by nivolumab has shown a promising response rate of 30.6% in a Phase II trial (CA209-678) for advanced hepatocellular carcinoma (HCC); however, the response mechanisms and relevant biomarkers remain unknown.

METHODS

By collecting both pretreatment and on-treatment samples, we performed multimodal profiling of tissue and blood samples and investigated molecular changes associated with favorable responses in 33 patients from the trial.

RESULTS

We found that higher tumor mutation burden, NCOR1 mutations and higher expression of interferon gamma pathways occurred more frequently in responders. Meanwhile, non-responders tended to be enriched for a novel Asian-specific transcriptomic subtype (Kaya_P2) with a high frequency of chromosome 16 deletions and upregulated cell cycle pathways. Strikingly, unlike other cancer types, we did not observe any association between T-cell populations and treatment response, but tumors from responders had a higher proportion of CXCL9+/CXCR3+ macrophages. Moreover, biomarkers discovered in previous immunotherapy trials were not predictive in the current cohort, suggesting a distinctive molecular landscape associated with differential responses to the combination therapy.

CONCLUSIONS

This study unraveled extensive molecular changes underlying distinctive responses to the novel treatment and pinpointed new directions for harnessing combination therapy in patients with advanced HCC.

Portrait of the Inflammatory Response to Radioiodine Therapy in Female Patients with Differentiated Thyroid Cancer with/without Type 2 Diabetes Mellitus

No clinical studies have investigated the effect of radioiodine (131I)-targeted therapy on the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as inflammatory response markers in patients with differentiated thyroid cancer (DTC) associated with type 2 diabetes mellitus (T2DM) and obesity. This study aimed to assess the relationship between blood radioactivity, body mass index (BMI), and peripheral blood cells three days after 131I intake in 56 female patients without T2DM (DTC/-T2DM) vs. 24 female patients with T2DM (DTC/+T2DM). Blood radioactivity, measured three days after 131I intake, was significantly lower in the DTC/+T2DM than in the DTC/-T2DM patients (0.7 mCi vs. 1.5 mCi, p < 0.001). The relationship between blood radioactivity and BMI (r = 0.83, p < 0.001), blood radioactivity and NLR (r = 0.53, p = 0.008), and BMI and NLR (r = 0.58, p = 0.003) indicates a possible connection between the bloodstream 131I uptake and T2DM-specific chronic inflammation. In patients without T2DM, 131I therapy has immunosuppressive effects, leading to increased NLR (19.6%, p = 0.009) and PLR (39.1%, p = 0.002). On the contrary, in the chronic inflammation context of T2DM, 131I therapy amplifies immune metabolism, leading to a drop in NLR (10%, p = 0.032) and PLR (13.4%, p = 0.021). Our results show that, in DTC/+T2DM, the bidirectional crosstalk between neutrophils and obesity may limit 131I uptake in the bloodstream. Considering the immune response to 131I therapy, the two groups of patients can be seen as a synchronous portrait of two sides. The explanation could lie in the different radiosensitivity of T and B lymphocytes, with T lymphocytes being predominant in patients with DTC/-T2DM and, most likely, B lymphocytes being predominant in T2DM.

Combined radiotherapy and immune checkpoint inhibition for the treatment of advanced hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is one of the most common cancers and a leading cause of cancer related death worldwide. Until recently, systemic therapy for advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B or C, was limited and ineffective in terms of long-term survival. However, over the past decade, immune check point inhibitors (ICI) combinations have emerged as a potential therapeutic option for patients with nonresectable disease. ICI modulate the tumor microenvironment to prevent progression of the tumor. Radiotherapy is a crucial tool in treating unresectable HCC and may enhance the efficacy of ICI by manipulating the tumor microenvironment and decreasing tumor resistance to certain therapies. We herein review developments in the field of ICI combined with radiotherapy for the treatment of HCC, as well as look at challenges associated with these treatment modalities, and review future directions of combination therapy.

Radiotherapy plus immune checkpoint inhibitor in prostate cancer

The immune checkpoint inhibitor (ICI) is a promising strategy for treating cancer. However, the efficiency of ICI monotherapy is limited, which could be mainly attributed to the tumor microenvironment of the "cold" tumor. Prostate cancer, a type of "cold" cancer, is the most common cancer affecting men's health. Radiotherapy is regarded as one of the most effective prostate cancer treatments. In the era of immune therapy, the enhanced antigen presentation and immune cell infiltration caused by radiotherapy might boost the therapeutic efficacy of ICI. Here, the rationale of radiotherapy combined with ICI was reviewed. Also, the scheme of radiotherapy combined with immune checkpoint blockades was suggested as a potential option to improve the outcome of patients with prostate cancer.

Friend or Foe? Locoregional Therapies and Immunotherapies in the Current Hepatocellular Treatment Landscape

Over the last several decades, a number of new treatment options for patients with hepatocellular carcinoma (HCC) have been developed. While treatment decisions for some patients remain clear cut, a large numbers of patients have multiple treatment options, and it can be hard for multidisciplinary teams to come to unanimous decisions on which treatment strategy or sequence of treatments is best. This article reviews the available data with regard to two treatment strategies, immunotherapies and locoregional therapies, with a focus on the potential of locoregional therapies to be combined with checkpoint inhibitors to improve outcomes in patients with locally advanced HCC. In this review, the available data on the immunomodulatory effects of locoregional therapies is discussed along with available clinical data on outcomes when the two strategies are combined.

Recent Advances in Image-Guided Locoregional Therapies for Primary Liver Tumors

Primary liver cancer is the leading cause of cancer-related deaths worldwide. with incidences predicted to rise over the next several decades. Locoregional therapies, such as radiofrequency or microwave ablation, are described as image-guided percutaneous procedures, which offer either a curative intent for early-stage hepatocellular carcinoma or bridging/downstaging for surgical resection or transplantation. Catheter-driven locoregional therapies, such as transarterial chemoembolization and radioembolization, induce tumor hypoxia, can be palliative, and improve survival for early-to-intermediate hepatocellular carcinoma and unresectable intrahepatic cholangiocarcinoma. Herein, we provide a comprehensive overview of the antineoplastic mechanisms underpinning locoregional therapies, different treatment approaches, and the current state of the literature for the efficacy of locoregional therapies for primary liver cancer. We also discuss emerging advancements, such as the adjuvant use of immunotherapies and molecular targeting agents with locoregional therapy, for the treatment of primary liver cancer.

Combination of Immunotherapy and Radiation Therapy in Gastrointestinal Cancers: An Appraisal of the Current Literature and Ongoing Research

Oncological outcomes are improving in gastrointestinal cancer with advancements in systemic therapies, and there is notable potential in combining immunotherapy and radiation therapy (RT) to allow for further improvements. Various preclinical and early phase II studies have shown promising synergy with immunotherapy and RT in gastrointestinal cancer. A few recent phase III studies have shown improved survival with the addition of immunotherapy to standard treatment for gastrointestinal cancer. The timing, duration, sequencing, and integration with other anti-cancer treatments are still areas of ongoing research. We have reviewed the published and ongoing studies of the combinations of immunotherapy and RT in gastrointestinal cancers.

A Paradigm Shift in Primary Liver Cancer Therapy Utilizing Genomics, Molecular Biomarkers, and Artificial Intelligence

Primary liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer-related death. Conventional therapies offer limited survival benefit despite improvements in locoregional liver-directed therapies, which highlights the underlying complexity of liver cancers. This review explores the latest research in primary liver cancer therapies, focusing on developments in genomics, molecular biomarkers, and artificial intelligence. Attention is also given to ongoing research and future directions of immunotherapy and locoregional therapies of primary liver cancers.

The Synergistic Effect of Interventional Locoregional Treatments and Immunotherapy for the Treatment of Hepatocellular Carcinoma

Immunotherapy has remarkably revolutionized the management of advanced HCC and prompted clinical trials, with therapeutic agents being used to selectively target immune cells rather than cancer cells. Currently, there is great interest in the possibility of combining locoregional treatments with immunotherapy for HCC, as this combination is emerging as an effective and synergistic tool for enhancing immunity. On the one hand, immunotherapy could amplify and prolong the antitumoral immune response of locoregional treatments, improving patients' outcomes and reducing recurrence rates. On the other hand, locoregional therapies have been shown to positively alter the tumor immune microenvironment and could therefore enhance the efficacy of immunotherapy. Despite the encouraging results, many unanswered questions still remain, including which immunotherapy and locoregional treatment can guarantee the best survival and clinical outcomes; the most effective timing and sequence to obtain the most effective therapeutic response; and which biological and/or genetic biomarkers can be used to identify patients likely to benefit from this combined approach. Based on the current reported evidence and ongoing trials, the present review summarizes the current application of immunotherapy in combination with locoregional therapies for the treatment of HCC, and provides a critical evaluation of the current status and future directions.

Potential Immunotherapy Targets for Liver-Directed Therapies, and the Current Scope of Immunotherapeutics for Liver-Related Malignancies

Liver cancer, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, is increasing in incidence and mortality across the globe. An improved understanding of the complex tumor microenvironment has opened many therapeutic doors and led to the development of novel pharmaceuticals targeting cellular signaling pathways or immune checkpoints. These interventions have significantly improved tumor control rates and patient outcomes, both in clinical trials and in real-world practice. Interventional radiologists play an important role in the multidisciplinary team given their expertise in minimally invasive locoregional therapy, as the bulk of these tumors are usually in the liver. The aim of this review is to highlight the immunological therapeutic targets for primary liver cancers, the available immune-based approaches, and the contributions that interventional radiology can provide in the care of these patients.

Interventional Oncology and Immuno-Oncology: Current Challenges and Future Trends

Personalized cancer treatments help to deliver tailored and biologically driven therapies for cancer patients. Interventional oncology techniques are able to treat malignancies in a locoregional fashion, with a variety of mechanisms of action leading to tumor necrosis. Tumor destruction determines a great availability of tumor antigens that can be recognized by the immune system, potentially triggering an immune response. The advent of immunotherapy in cancer care, with the introduction of specific immune checkpoint inhibitors, has led to the investigation of the synergy of these drugs when used in combination with interventional oncology treatments. The aim of this paper is to review the most recent advances in the field of interventional oncology locoregional treatments and their interactions with immunotherapy.

Cancer Immunology: Impact of Radioembolization of Hepatocellular Carcinoma on Immune Response Modulation

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer and the fourth most common cause of cancer mortality. The tumor microenvironment (TME) is increasingly recognized as having a central role in HCC carcinogenesis, with factors such as tumor and immune cell interactions, cytokines, and extracellular matrix serving key roles. Transarterial radioembolization (TARE) is a locoregional therapy for HCC that not only has a direct tumoricidal effect, but induces an immune response against tumor cells with subsequent immunogenic cell death. This TARE-induced tumor immunogenicity occurs through enhancement of tumor-associated antigen expression, as well as recruitment and diversification of tumor-infiltrating lymphocytes. In addition, immunologically related biomarkers, including the neutrophil-to-lymphocyte ratio, lymphocyte count, and cytokine levels, may be useful tools to predict outcomes after TARE. Early data are promising regarding the potential synergistic benefit from treatment algorithms that combine TARE and immunotherapies, and interest is growing in the clinical application of such combinations. This review provides an overview of cancer immunology, summarizes the available data regarding the biologic effects of TARE on local and systemic immune responses, and explores the potential role of the combination of TARE and immunotherapy for HCC.

Compartmentalization and persistence of dominant (regulatory) T cell clones indicates antigen skewing in juvenile idiopathic arthritis

Autoimmune inflammation is characterized by tissue infiltration and expansion of antigen-specific T cells. Although this inflammation is often limited to specific target tissues, it remains yet to be explored whether distinct affected sites are infiltrated with the same, persistent T cell clones. Here, we performed CyTOF analysis and T cell receptor (TCR) sequencing to study immune cell composition and (hyper-)expansion of circulating and joint-derived Tregs and non-Tregs in juvenile idiopathic arthritis (JIA). We studied different joints affected at the same time, as well as over the course of relapsing-remitting disease. We found that the composition and functional characteristics of immune infiltrates are strikingly similar between joints within one patient, and observed a strong overlap between dominant T cell clones, especially Treg, of which some could also be detected in circulation and persisted over the course of relapsing-remitting disease. Moreover, these T cell clones were characterized by a high degree of sequence similarity, indicating the presence of TCR clusters responding to the same antigens. These data suggest that in localized autoimmune disease, there is autoantigen-driven expansion of both Teffector and Treg clones that are highly persistent and are (re)circulating. These dominant clones might represent interesting therapeutic targets.

Nanoparticles augment the therapeutic window of RT and immunotherapy for treating cancers: pivotal role of autophagy

Immunotherapies are now emerging as an efficient anticancer therapeutic strategy. Cancer immunotherapy utilizes the host's immune system to fight against cancer cells and has gained increasing interest due to its durable efficacy and low toxicity compared to traditional antitumor treatments, such as chemotherapy and radiotherapy (RT). Although the combination of RT and immunotherapy has drawn extensive attention in the clinical setting, the overall response rates are still low. Therefore, strategies for further improvement are urgently needed. Nanotechnology has been used in cancer immunotherapy and RT to target not only cancer cells but also the tumor microenvironment (TME), thereby helping to generate a long-term immune response. Nanomaterials can be an effective delivery system and a strong autophagy inducer, with the ability to elevate autophagy to very high levels. Interestingly, autophagy could play a critical role in optimal immune function, mediating cell-extrinsic homeostatic effects through the regulation of danger signaling in neoplastic cells under immunogenic chemotherapy and/or RT. In this review, we summarize the preclinical and clinical development of the combination of immunotherapy and RT in cancer therapy and highlight the latest progress in nanotechnology for augmenting the anticancer effects of immunotherapy and RT. The underlying mechanisms of nanomaterial-triggered autophagy in tumor cells and the TME are discussed in depth. Finally, we suggest the implications of these three strategies combined together to achieve the goal of maximizing the therapeutic advantages of cancer therapy and show recent advances in biomarkers for tumor response in the evaluation of those therapies.

Prospective Evaluation of Immune Activation Associated with Response to Radioembolization Assessed with PET/CT in Women with Breast Cancer Liver Metastasis

Background The impact of transarterial radioembolization (TARE) of breast cancer liver metastasis (BCLM) on antitumor immunity is unknown, which hinders the optimal selection of candidates for TARE. Purpose To determine whether response to TARE at PET/CT in participants with BCLM is associated with specific immune markers (cytokines and immune cell populations). Materials and Methods This prospective pilot study enrolled 23 women with BCLM who planned to undergo TARE (June 2018 to February 2020). Peripheral blood and liver tumor biopsies were collected at baseline and 1-2 months after TARE. Monocyte, myeloid-derived suppressor cell (MDSC), interleukin (IL), and tumor-infiltrating lymphocyte (TIL) levels were assessed with use of gene expression studies and flow cytometry, and immune checkpoint and cell surface marker levels with immunohistochemistry. Modified PET Response Criteria in Solid Tumors was used to determine complete response (CR) in treated tissue. After log-transformation, immune marker levels before and after TARE were compared using paired t tests. Association with CR was assessed with Wilcoxon rank-sum or unpaired t tests. Results Twenty women were included. After TARE, peripheral IL-6 (geometric mean, 1.0 vs 1.6 pg/mL; P = .02), IL-10 (0.2 vs 0.4 pg/mL; P = .001), and IL-15 (1.9 vs 2.4 pg/mL; P = .01) increased. In biopsy tissue, lymphocyte activation gene 3-positive CD4+ TILs (15% vs 31%; P < .001) increased. Eight of 20 participants (40% [exact 95% CI: 19, 64]) achieved CR. Participants with CR had lower baseline peripheral monocytes (10% vs 29%; P < .001) and MDSCs (1% vs 5%; P < .001) and higher programmed cell death protein (PD) 1-positive CD4+ TILs (59% vs 26%; P = .006) at flow cytometry and higher PD-1+ staining in tumor (2% vs 1%; P = .046). Conclusion Complete response to transarterial radioembolization was associated with lower baseline cytokine, monocyte, and myeloid-derived suppressor cell levels and higher programmed cell death protein 1-positive tumor-infiltrating lymphocyte levels. © RSNA, 2022 Online supplemental material is available for this article.