Radioembolisation with Y90-resin microspheres followed by nivolumab for advanced hepatocellular carcinoma (CA 209-678): a single arm, single centre, phase 2 trial

Yttrium-90 radioembolization treatment strategies for management of hepatocellular carcinoma

As the third leading cause of cancer-related deaths worldwide, hepatocellular carcinoma (HCC) represents a significant global health challenge. This paper provides an introduction and comprehensive review of transarterial radioembolization (TARE) with Yttrium-90 (Y90), a widely performed transcatheter procedure for HCC patients who are not suitable candidates for surgery. TARE involves the targeted delivery of radioactive microspheres to liver tumors, offering a promising treatment option for managing HCC across various stages of the disease. By evaluating Y90 TARE outcomes across early, intermediate, and advanced stages of HCC, the review aims to present a thorough understanding of its efficacy and safety. Additionally, this paper highlights future research directions focusing on the potential of combination therapies with systemic and immunotherapies, as well as personalized treatments. The exploration of these innovative approaches aims to improve treatment outcomes, reduce adverse events, and provide new therapeutic opportunities for HCC patients. The review underscores the importance of ongoing research and clinical trials to optimize TARE further and integrate it into comprehensive HCC treatment paradigms.

Respiratory adverse effects in patients treated with immune checkpoint inhibitors in combination with radiotherapy: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to assess the risk of respiratory adverse effects in patients with solid tumors treated with immune checkpoint inhibitors (PD-1, PD-L1 and CTLA-4 inhibitors) in combination with radiation therapy.

METHODS

We selected eligible studies through the following databases: PubMed, Embase, Cochrane Library, and Clinicaltrials ( https://clinicaltrials.gov/ ). The data was analyzed by using Rstudio.

RESULTS

Among 3737 studies, 26 clinical trials, including 2670 patients, were qualified for the meta-analysis. We evaluated the incidence rates of adverse respiratory events, including cough, pneumonia, upper respiratory tract infections, and others: grades 1-5 cough, 0.176 (95%CI: 0.113-0.274, I2 = 92.36%); grades 1-5 pneumonitis, 0.118 (95%CI: 0.067-0.198, I2 = 88.64%); grades 1-5 upper respiratory tract infection, 0.064 (95%CI: 0.049-0.080, I2 = 0.98%); grades 3-5 cough, 0.050 (95%CI: 0.012-0.204, I2 = 8.90%); grades 3-5 pneumonitis, 0.052 (95%CI: 0.031-0.078, I2 = 83.86%); grades 3-5 upper respiratory tract infection, 0.040 (95%CI: 0.007-0.249, I2 = 45.31%).

CONCLUSIONS

Our meta-analysis demonstrated that ICI combined with radiotherapy for solid tumors can produce respiratory adverse effects. ICIs combination treatment, a tumor located in the chest, is more likely to cause adverse reactions, and SBRT treatment and synchronous treatment will bring less incidence of adverse reactions. This study provide insights for clinicians to balance the risks of radiotherapy in the course of treating oncology patients.

New frontiers in radioembolization

Radioembolization is a locoregional transarterial therapy that combines radionuclide and micron-sized beads to deliver radiation internally to the target tumors based on the arterial blood flow. While initially developed as a palliative treatment option, radioembolization is now used for curative intent treatment, neoadjuvant therapy, and method to downstage or bridge for liver transplant. Radioembolization has become increasingly utilized and is an important therapeutic option for the management of hepatocellular carcinoma and liver metastasis. This article provides an overview of the techniques, challenges, and novel developments in radioembolization, including new dosimetry techniques, radionuclides, and new target tumors.

Complete Response to Locoregional Therapy Plus Immunotherapy for Hepatocellular Carcinoma

Importance

Previous studies showed that 42% to 50% of patients with locally advanced hepatocellular carcinoma (HCC) achieved complete remission (CR) after combined locoregional therapy (LRT) plus immunotherapy (IO). However, data on predictors of CR and long-term clinical outcomes without surgery and after discontinuation of IO are lacking.

Objective

To assess the long-term clinical outcomes among patients with unresectable HCC who achieved CR after LRT-IO and were placed on a watch-and-wait protocol.

Design, Setting, and Participants

This cohort study included patients with unresectable HCC who achieved CR after LRT-IO in 2 prospective studies between January 2018 and December 2022. The time of data cutoff was June 2023. Radiologic CR was defined per modified Response Evaluation Criteria in Solid Tumors. All patients underwent close surveillance after CR without surgical interventions, and IO was discontinued.

Exposure

All patients had received stereotactic body radiotherapy followed by anti-programmed cell death protein 1 or anti-programmed death ligand 1 therapy. Forty-nine patients had received a dose of transarterial chemoembolization before stereotactic body radiotherapy.

Main Outcomes and Measures

The primary outcome was the 3-year overall survival (OS) rate. Secondary outcomes included the 3-year time-to-progression rate, 3-year local control rate, and relapse pattern. Factors associated with CR were analyzed using multivariate analyses.

Results

A total of 63 patients were enrolled (58 male [92.1%]; median age, 69 years [range, 18-90 years]); 38 patients (60.3%) had macrovascular invasion, and the median tumor diameter was 10 cm (range, 3.8-31.1 cm). The median follow-up time was 34.7 months (95% CI, 6.5-64.6 months). Twenty-nine patients (46.0%) achieved CR. The patients achieving CR had a significantly better 3-year OS rate than patients not achieving CR (75.5% [95% CI, 58.2%-98.3%] vs 28.1% [95% CI, 7.4%-29.4%]; P < .001). Among the 29 patients with CR, the 3-year time-to-progression rate was 58.7% (95% CI, 38.7%-79.1%) and the 3-year local control rate was 90.5% (95% CI, 78.2%-100%). Ten patients (34.5%) developed recurrence; among them, 6 (60.0%) with solitary intrahepatic disease relapse underwent curative surgical treatment. The absence of tumor vascular invasion (odds ratio, 0.30; 95% CI, 0.10-0.89) and the sum of the largest lesion diameters of 8 cm or less (odds ratio, 0.26; 95% CI, 0.07-0.98) were associated with CR.

Conclusions and Relevance

This cohort study of LRT-IO with long-term follow-up data found a durable response in patients with locally advanced unresectable HCC. Long-term survival was attainable in patients with radiologic CR. Further randomized clinical trials are warranted.

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.

Multidisciplinary Delphi Consensus on Safety of Combining Transarterial Radioembolization with Yttrium-90 Microspheres with Systemic Anticancer Agents for the Treatment of Liver Malignancy

PURPOSE

To provide guidance, via multidisciplinary consensus statements, on the safety interactions between systemic anticancer agents (such as radiosensitizing chemotherapy, immunotherapy, targeted therapy, and peptide receptor radionuclide therapy) and transarterial radioembolization (TARE) with yttrium-90 (90Y)-labeled microspheres in the treatment of primary and metastatic liver malignancies.

MATERIALS AND METHODS

A literature search identified 59 references that informed 26 statements on the safety of 90Y TARE combined with systemic therapies. Modified Delphi method was used to develop consensus on statements through online anonymous surveys of the 12 panel members representing the fields of interventional radiology, medical oncology, surgical oncology, hepatology, and pharmacy, focusing on hepatocellular carcinoma (HCC), metastatic colorectal cancer (mCRC), neuroendocrine tumors, metastatic breast cancer, and intrahepatic cholangiocarcinoma.

RESULTS

High-level evidence was limited. Level 1 data in patients with mCRC suggest that some radiosensitizing chemotherapies (eg, oxaliplatin) require temporary dose reduction when used concomitantly with 90Y TARE, and some targeted therapies (eg, vascular endothelial growth factor inhibitors and antiangiogenic tyrosine kinase inhibitors) should be avoided for at least 4 weeks before 90Y TARE. In patients with HCC, the feasibility of 90Y TARE and immunotherapy has been demonstrated with Level 4 evidence. Data are more limited for other primary and secondary liver malignancies, and consensus statements were driven by expert opinion (Level 5).

CONCLUSIONS

Given the absence of evidence-based guidelines on the safety of 90Y TARE in combination with systemic anticancer therapy, these consensus statements provide expert guidance on the potential risks when considering specific combinations.

Progress of immune checkpoint inhibitors in the treatment of advanced hepatocellular carcinoma

Among primary liver cancers, hepatocellular carcinoma is the most common pathological type. Its onset is insidious, and most patients have no obvious discomfort in the early stage, so it is found late, and the opportunity for surgical radical treatment is lost, resulting in a poor prognosis. With the introduction of molecular-targeted drugs represented by sorafenib, patients with middle- and late-stage liver cancer have regained the light of day. However, their therapeutic efficacy is relatively low due to the limited target of drug action, toxic side effects, and other reasons. At this time, the emergence of immunotherapy represented by immune checkpoint inhibitors (ICIs) well breaks this embarrassing situation, which mainly achieves the anti-tumor purpose by improving the tumor immune microenvironment. Currently, ICI monotherapy, as well as combination therapy, has been widely used in the clinic, further prolonging the survival of patients with advanced hepatocellular carcinoma. This article reviews the development of monotherapy and combination therapy for ICIs in advanced hepatocellular carcinoma and the latest research progress.

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.

Conversion therapy for advanced hepatocellular carcinoma in the era of precision medicine: Current status, challenges and opportunities

Hepatocellular carcinoma (HCC), the most prevalent malignancy of the digestive tract, is characterized by a high mortality rate and poor prognosis, primarily due to its initial diagnosis at an advanced stage that precludes any surgical intervention. Recent advancements in systemic therapies have significantly improved oncological outcomes for intermediate and advanced-stage HCC, and the combination of locoregional and systemic therapies further facilitates tumor downstaging and increases the likelihood of surgical resectability for initially unresectable cases following conversion therapies. This shift toward high conversion rates with novel, multimodal treatment approaches has become a principal pathway for prolonged survival in patients with advanced HCC. However, the field of conversion therapy for HCC is marked by controversies, including the selection of potential surgical candidates, formulation of conversion therapy regimens, determination of optimal surgical timing, and application of adjuvant therapy post-surgery. Addressing these challenges and refining clinical protocols and research in HCC conversion therapy is essential for setting the groundwork for future advancements in treatment strategies and clinical research. This narrative review comprehensively summarizes the current strategies and clinical experiences in conversion therapy for advanced-stage HCC, emphasizing the unresolved issues and the path forward in the context of precision medicine. This work not only provides a comprehensive overview of the evolving landscape of treatment modalities for conversion therapy but also paves the way for future studies and innovations in this field.

Safety and Efficacy of 90Y Selective Internal Radiation Therapy Using Glass Microspheres in Hepatocellular Carcinoma: A Southeast Asian Single-Institution Initial Experience

Our objective was to demonstrate primarily the safety and secondarily the efficacy of 90Y glass microspheres in selective internal radiation therapy (SIRT) for hepatocellular carcinoma (HCC) in a local Southeast Asian hospital. Methods: Eleven consecutive patients with small, unresectable, nonmetastatic HCC and referred for locoregional therapy with SIRT with a curative intention were followed up for 6 mo after the procedure by way of interviews, blood tests, and anatomic scans. Results: Although 5 patients had deranged liver function tests after the procedure, in only 1 patient did this constitute a grade 1 toxicity (in alkaline phosphatase) by the Common Terminology Criteria for Adverse Events. Half the patients showed a reduction in serum α-fetoprotein measurements, and 6 of 11 patients demonstrated an objective response (complete or partial) on imaging. Conclusion: SIRT with 90Y glass microspheres is a safe and efficacious locoregional therapy for unresectable HCC. There are similar articles published in the West; however, the patient population there comprises far fewer Asians and the underlying cause for HCC is different from that in the Asian population. Despite these differences, SIRT is an equally effective and safe option for such patients.

Combination and Optimal Sequencing of Systemic and Locoregional Therapies in Hepatocellular Carcinoma: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

Hepatocellular carcinoma, historically, has had a poor prognosis with very few systemic options. Furthermore, most patients at diagnosis are not surgical candidates. Therefore, locoregional therapy (LRT) has been widely used, with strong data supporting its use. Over the last 15 years, there has been progress in the available systemic agents. This has led to the updated Barcelona Clinic Liver Cancer (BCLC) algorithm's inclusion of these new systemic agents, with advocacy of earlier usage in those who progress on LRT or have tumor characteristics that make them less likely to benefit from LRT. However, neither the adjunct of LRT nor the specific sequencing of combination therapies is addressed directly. This Research Consensus Panel sought to highlight research priorities pertaining to the combination and optimal sequencing of LRT and systemic therapy, assessing the greatest needs across BCLC stages.

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.

Survival Outcome Analysis of Stereotactic Body Radiotherapy and Immunotherapy (SBRT-IO) versus SBRT-Alone in Unresectable Hepatocellular Carcinoma

Introduction

While combination of stereotactic body radiotherapy (SBRT) and immunotherapy are promising, their efficacy and safety have not been compared with SBRT-alone in patients with unresectable hepatocellular carcinoma (HCC).

Methods

This retrospective study included 100 patients with nonmetastatic, unresectable HCC in two hospitals. Eligible patients had tumor nodules ≤3 and Child-Pugh liver function score of A5 to B7. Seventy patients received SBRT-alone, and 30 patients underwent combined SBRT and immunotherapy (SBRT-IO). Overall survival (OS), time to progression (TTP), overall response rate (ORR), and toxicity were analyzed. We adjusted for the potential confounding factors using propensity score matching.

Results

The median tumor size was 7.3 cm (range, 2.6-18 cm). Twenty-five (25%) of patients had vascular invasion. Before propensity score matching, the 1-year and 3-year OS rate was 89.9% and 59.8% in the SBRT-IO group and 75.7% and 42.3% in SBRT-alone group (p = 0.039). After propensity score matching (1:2), 25 and 50 patients were selected from the SBRT-IO and SBRT-alone group. The 1-year and 3-year OS was 92.0% and 63.9% in the SBRT-IO group versus 74.0% and 43.3% in the SBRT-alone group (p = 0.034). The 1-year and 3-year TTP was better in SBRT-IO group (1-year: 68.9% vs. 58.9% and 3-year: 61.3% vs. 32.5%, p = 0.057). The ORR of 88% (complete response [CR]: 56%, partial response [PR]: 22%) in SBRT-IO arm was significantly better than 50% (CR: 20%, PR: 30%) in the SBRT-alone arm (p = 0.006). Three patients (12%) developed ≥grade 3 immune-related treatment adverse events (n = 2 hepatitis, n = 1 dermatitis) leading to permanent treatment discontinuation.

Conclusion

Adding immunotherapy to SBRT resulted in better survival with manageable toxicities. Prospective randomized trial is warranted.

Present and future of new systemic therapies for early and intermediate stages of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a high mortality neoplasm which usually appears on a cirrhotic liver. The therapeutic arsenal and subsequent prognostic outlook are intrinsically linked to the HCC stage at diagnosis. Notwithstanding the current deployment of treatments with curative intent (liver resection/local ablation and liver transplantation) in early and intermediate stages, a high rate of HCC recurrence persists, underscoring a pivotal clinical challenge. Emergent systemic therapies (ST), particularly immunotherapy, have demonstrate promising outcomes in terms of increase overall survival, but they are currently bound to the advanced stage of HCC. This review provides a comprehensive analysis of the literature, encompassing studies up to March 10, 2024, evaluating the impact of novel ST in the early and intermediate HCC stages, specially focusing on the findings of neoadjuvant and adjuvant regimens, aimed at increasing significantly overall survival and recurrence-free survival after a treatment with curative intent. We also investigate the potential role of ST in enhancing the downstaging rate for the intermediate-stage HCC initially deemed ineligible for treatment with curative intent. Finally, we critically discuss about the current relevance of the results of these studies and the encouraging future implications of ST in the treatment schedules of early and intermediate HCC stages.

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.

Concurrent nivolumab and external beam radiation therapy for hepatocellular carcinoma with macrovascular invasion: A phase II study

Background and Aims

Nivolumab was the first immune checkpoint inhibitor approved for hepatocellular carcinoma (HCC). External beam radiation therapy (EBRT) is locally effective and may enhance the effectiveness of immunotherapy. This study investigated the efficacy and safety of concurrent nivolumab and EBRT in HCC with macrovascular invasion.

Methods

In this phase II multicenter trial, patients with HCC and macrovascular invasion were concurrently treated with intravenous nivolumab (3 mg/kg every 2 weeks) and EBRT, followed by maintenance nivolumab until progression or unacceptable toxicity. Primary endpoints were progression-free survival (PFS) and safety, and secondary endpoints were overall survival, time-to-progression, objective response rate, and disease control rate.

Results

Between January 2020 and June 2021, 50 patients (male 84%, median age 62.5) were enrolled; 47 (94.0%) and 13 (26.0%) with portal (Vp1/2, n = 21; Vp3, n = 23; Vp4, n = 3) and hepatic vein invasion, respectively. Patients received EBRT (median dose: 50 [IQR 43-50] Gy) after the first nivolumab dose. The median number of nivolumab doses was 8.5. Median PFS was 5.6 (90% CI 3.6-9.9) months. Median overall survival and time-to-progression were 15.2 (90% CI 10.8-19.6) and 5.6 (90% CI 3.6-9.9) months, respectively. The objective response rate and disease control rate were 36.0% and 74.0%, respectively. The median duration of response was 9.9 months. Of 35 patients with follow-up data, 23 received subsequent systemic treatment, including atezolizumab-bevacizumab, sorafenib, lenvatinib, and regorafenib. Treatment-related any grade adverse events (AEs) and grade 3/4 AEs occurred in 40 (80.0%) and 6 (12.0%) patients, respectively. Common treatment-related AEs included pruritus (38.0%) and rash (16.0%), with no treatment-related deaths.

Conclusion

Concurrent nivolumab therapy and EBRT showed encouraging PFS with acceptable safety in patients with advanced HCC and macrovascular invasion.

Impact and implications

Immune checkpoint inhibitors, the standard care for advanced hepatocellular carcinoma (HCC), show relatively poor therapeutic effects in patients with advanced HCC and macrovascular invasion. In this investigator-initiated phase II study, we, for the first time, show that concurrent external beam radiation therapy with nivolumab, an immune checkpoint inhibitor, led to encouraging progression-free survival in patients with HCC and macrovascular invasion. The concurrent treatment was tolerable without significant safety concerns. Further randomized studies investigating the combination of immunotherapy and external beam radiation therapy are required.

ClinicalTrialsgov identifier

NCT04611165.

Immunotherapy and Radiation Therapy Combinatorial Approaches in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), a prevalent and often fatal liver cancer, presents significant treatment challenges, especially in its advanced stages. This article delves into the promising approach of combining immunotherapy, particularly immune checkpoint inhibitors, with radiation therapy, a cornerstone of HCC management. Our review synthesizes current preclinical and clinical research, highlighting the potential synergistic effects of this combinational treatment. Emerging evidence suggests that this synergy enhances tumor control and improves patient survival rates. The combination leverages the localized, tumor-targeting ability of radiation therapy and the systemic, immune-boosting effects of immunotherapy, potentially overcoming the limitations inherent in each treatment modality when used separately. This integrative approach is especially promising in addressing the complex tumor microenvironment of HCC. However, the treatment landscape is nuanced, with challenges such as patient-specific response variability and potential resistance to therapies. Future research directions should focus on refining these combination strategies, tailoring them to individual patient profiles, and understanding the underlying mechanisms that govern the interaction between immunotherapy and radiation therapy. Such advancements could significantly improve HCC management, setting new standards for patient care and treatment efficacy.

Integrating the new systemic treatment landscape and surgical therapy in hepatocellular carcinoma

The treatment landscape of hepatocellular carcinoma has evolved rapidly within the last decade. Minimally-invasive techniques have reached a new level of safety, affording surgeons to pursue more aggressive treatment strategies to ultimately improve oncological outcomes. These procedures have been increasingly applied to treat patients with more progressed tumors and in select case even patients with advanced stage disease confined to the liver. Concomitantly, a dramatic increase in research into immunotherapy has altered the treatment paradigm in advanced disease stages, where the emerging treatment regimens can provide durable responses in a subset of the patient population for whom prognosis is dramatically improved. These treatments are now tested in early-stage disease to address the pressing unmet need of high recurrence rates after resection and in intermediate stage to complement the proven efficacy of intraarterial embolization in delaying progression. This review provides an in-depth discussion of these trends and describes how the treatment landscape has already changed and which impediments remain.

Progress in the treatment of advanced hepatocellular carcinoma with immune combination therapy

Advanced hepatocellular carcinoma (HCC) is a severe malignancy that poses a serious threat to human health. Owing to challenges in early diagnosis, most patients lose the opportunity for radical treatment when diagnosed. Nonetheless, recent advancements in cancer immunotherapy provide new directions for the treatment of HCC. For instance, monoclonal antibodies against immune checkpoint inhibitors (ICIs) such as programmed cell death protein 1/death ligand-1 inhibitors and cytotoxic t-lymphocyte associated antigen-4 significantly improved the prognosis of patients with HCC. However, tumor cells can evade the immune system through various mechanisms. With the rapid development of genetic engineering and molecular biology, various new immunotherapies have been used to treat HCC, including ICIs, chimeric antigen receptor T cells, engineered cytokines, and certain cancer vaccines. This review summarizes the current status, research progress, and future directions of different immunotherapy strategies in the treatment of HCC.

Enhanced therapeutic outcomes with atezolizumab-bevacizumab and SIRT combination compared to SIRT alone in unresectable HCC: A promising approach for improved survival

BACKGROUND

Integrating immunotherapy with locoregional therapies marks a significant milestone in the realm of hepatocellular carcinoma (HCC) treatment . This study aimed to assess the impact of addition of Atezolizumab-Bevacizumab (AtezoBev) on the outcome patients treated with SIRT.

METHODS

We conducted a study that included all Child-Pugh A HCC treated with SIRT since 2017. We examined the effects of the addition of 3 infusions of AtezoBev before the SIRT procedure and after SIRT on patients outcome (AtezoBev-SIRT group). Time-to-event data were analyzed using Kaplan-Meier with the log-rank test.

RESULTS

Thirty five HCC patients treated with SIRT were included, of whom 23 % also received AtezoBev infusions. The two groups were similar in terms of liver function and HCC parameters. The median OS was not reached for patients who received AtezoBev in combination with SIRT and 14 months for patients only treated by SIRT. The median PFS was higher in the group treated by SIRT and AtezoBev vs SIRT alone (11.3 months vs 5.8 months). In the global cohort, 8 patients presented a downstaging (23 %), 4 underwent liver surgery (1 in the AtezoBev-SIRT group) and 4 liver transplantation (1 in the AtezoBev-SIRT group) CONCLUSIONS: The administration of AtezoBev, both before and after SIRT, is associated with enhanced OS and PFS outcomes compared to SIRT alone for unresectable HCC.

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.

Destabilizing the genome as a therapeutic strategy to enhance response to immune checkpoint blockade: a systematic review of clinical trials evidence from solid and hematological tumors

Background: Genomic instability is increased alterations in the genome during cell division and is common among most cancer cells. Genome instability enhances the risk of initial carcinogenic transformation, generating new clones of tumor cells, and increases tumor heterogeneity. Although genome instability contributes to malignancy, it is also an "Achilles' heel" that constitutes a therapeutically-exploitable weakness-when sufficiently advanced, it can intrinsically reduce tumor cell survival by creating DNA damage and mutation events that overwhelm the capacity of cancer cells to repair those lesions. Furthermore, it can contribute to extrinsic survival-reducing events by generating mutations that encode new immunogenic antigens capable of being recognized by the immune system, particularly when anti-tumor immunity is boosted by immunotherapy drugs. Here, we describe how genome-destabilization can induce immune activation in cancer patients and systematically review the induction of genome instability exploited clinically, in combination with immune checkpoint blockade. Methods: We performed a systematic review of clinical trials that exploited the combination approach to successfully treat cancers patients. We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and publication from the reference list of related articles. The most relevant inclusion criteria were peer-reviewed clinical trials published in English. Results: We identified 1,490 studies, among those 164 were clinical trials. A total of 37 clinical trials satisfied the inclusion criteria and were included in the study. The main outcome measurements were overall survival and progression-free survival. The majority of the clinical trials (30 out of 37) showed a significant improvement in patient outcome. Conclusion: The majority of the included clinical trials reported the efficacy of the concept of targeting DNA repair pathway, in combination with immune checkpoint inhibitors, to create a "ring of synergy" to treat cancer with rational combinations.

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.

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.

Safety and Efficacy of Concurrent Atezolizumab/Bevacizumab or Nivolumab Combination Therapy with Yttrium-90 Radioembolization of Advanced Unresectable Hepatocellular Carcinoma

To evaluate the safety and efficacy of combining yttrium-90 radioembolization (Y90-RE) with immune checkpoint inhibitor therapy, consecutive advanced unresectable hepatocellular carcinoma (HCC) patients treated between 2016 and 2022 with atezolizumab/bevacizumab or nivolumab within three-months pre- and post-Y90-RE were retrospectively evaluated. Tumor response and treatment-related clinical/laboratory adverse events (AE) were assessed at 1 and 6 months, as well as differences in clinical and laboratory variables and median overall survival (OS) from initial treatment (whether it was Y90-RE or systemic therapy) between the two cohorts. A total of 19 patients (10 atezolizumab/bevacizumab; 9 nivolumab), comprising 84% males with median age 69 years, met the inclusion criteria. Compared to the atezolizumab/bevacizumab group, there were less males (100% vs. 67%; p = 0.02) and more ECOG ≥ 2 patients in the nivolumab group (0% vs. 33%; p = 0.02). Baseline characteristics or incidence of 6-month post-treatment any-grade AE (60% vs. 56%; p = 0.7), grade ≥ 3 AE (0% vs. 11%; p = 0.3), objective response (58% total, 60% vs. 56%; p = 0.7), and complete response (16% total; 10% vs. 22%; p = 0.8) were similar between the atezolizumab/bevacizumab and the nivolumab cohorts. Median OS was 12.9 months for the whole cohort, 16.4 months for nivolumab, and 10.7 months for atezolizumab/bevacizumab. Among patients with advanced unresectable HCC, the utilization of Y90-RE concurrently or within 90 days of nivolumab or atezolizumab/bevacizumab immunotherapy, appears to be well-tolerated and with a low incidence of severe AE.

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.

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.

PD-1 combined with lenvatinib and TACE for the transformational treatment of hepatocellular carcinoma combined with portal vein tumor thrombus: a case report and literature review

Background

The prognosis of hepatocellular carcinoma combined with portal vein tumor thrombus is poor, with a median survival of only 3-6 months. PD-1 combined with targeted therapy may provide an opportunity for patients with BCLC C stage hepatocellular carcinoma combined with portal vein tumor thrombus to undergo radical surgery, significantly prolonging their survival time.

Case presentation

A middle-aged 51-year-old male who was diagnosed with hepatocellular carcinoma combined with portal vein main stem tumor thrombus at our center in May 2020, with a BCLC stage of C, liver cirrhosis, HBV infection, and preoperative evaluation as unresectable. The liver function was Child-Pugh A. The initial treatment was lenvatinib combined with PD-1 therapy, followed by one cycle of TACE treatment. The tumor and thrombus volume significantly reduced, followed by continuous TACE combined with immunotherapy and targeted therapy, leading to the appearance of portal vein main stem emboli. After multidisciplinary discussion, surgical resection was performed, and the embolus was removed, achieving a cure. The patient has been tumor-free for over 34 months.

Conclusion

PD-1 combined with lenvatinib and local TACE create conditions for radical surgery, and it is hoped that more real-world research data can provide better evidence for the transformational treatment of hepatocellular carcinoma combined with portal vein tumor thrombus.

Adverse events of immune checkpoint inhibitors in hepatocellular carcinoma: a systemic review and meta-analysis

The introduction of immune checkpoint inhibitors (ICIs) has reshaped the therapy of hepatocellular carcinoma (HCC). ICIs are a novel therapy with frequent adverse events (AEs), including treatment-related adverse events (trAEs) and immune-related adverse events (irAEs). However, no comprehensive overview of the toxicity spectrum of ICIs in HCC patients has been provided. Electronic databases were searched to identify eligible studies. A meta-analysis of the incidence rate of AEs in HCC patients treated with ICIs was performed. Lastly, the prognostic value of irAEs in HCC patients treated with ICIs was verified. Forty-seven studies with 6472 participations met the inclusion criteria. The pooled all-grade trAEs incidence rate was 83.4% (95% confidence interval [95% CI] 77.0-89.1%), ≥ grade 3 trAEs incidence rate was 33.0% (95% CI 26.9-39.5%), all-grade irAEs incidence rate was 34% (95% CI 22-47%), and ≥ grade 3 irAEs incidence rate was 9% (95% CI 5-14%). Aspartate aminotransferase (AST) increase (38%, 95% CI 35-40%) is the most common trAEs. Fatigue (14%, 95% CI 7-23%) is the most common irAEs. The pooled results also showed that 18.8% (95% CI 13.2-25.2%) of patients required systemic steroid therapy due to AEs, while 6.6% (95% CI 4.6-9.0%) of patients withdrew from treatment due to AEs. Additionally, patients experiencing irAEs may have a better progression-free survival (PFS) (multivariate analysis: hazard ratio [HR] = 0.41, 95% CI 0.27-0.61, I2 = 36.3%) but not overall survival (OS) (multivariate analysis: HR = 0.54, 95% CI 0.22-1.36, I2 = 83.2%) than those with no irAEs. Our study presents a systemic assessment of the AEs profile in HCC patients receiving ICIs, providing important reference for clinicians on toxicity profile. Besides, patients with irAEs may have a better PFS. More large-scale and prospective studies are needed to confirm our conclusions.

Contemporary applications of Y90 for the treatment of hepatocellular carcinoma

Transarterial radioembolization (TARE) with yttrium-90 (90Y) microspheres has been widely adopted for the treatment of HCC. Recent advances in yttrium-90 (90Y) dosimetry have led to durable local responses. Radiation segmentectomy has become a viable alternative to thermal ablation for early-stage HCC (Barcelona Clinic Liver Cancer 0 and A) and has been commonly used as a bridge to transplant. TARE is also commonly used for downstaging to transplant using traditional lobar dosimetry and radiation segmentectomy techniques. Radiation lobectomy has a dual role in local tumor control and induction of contralateral liver lobe hypertrophy as a bridge to resection for patients with an inadequate future liver remnant. TARE continues to provide disease control for patients with limited vascular invasion and may be an alternative to systemic therapy for patients with localized advanced disease. The potential synergy between TARE and immunotherapy has been recognized, and prospective studies evaluating this combination are needed for patients with Barcelona Clinic Liver Cancer B and C 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.

Unleashing the efficacy of immune checkpoint inhibitors for advanced hepatocellular carcinoma: factors, strategies, and ongoing trials

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer, representing approximately 85% of cases. The diagnosis is often made in the middle and late stages, necessitating systemic treatment as the primary therapeutic option. Despite sorafenib being the established standard of care for advanced HCC in the past decade, the efficacy of systemic therapy remains unsatisfactory, highlighting the need for novel treatment modalities. Recent breakthroughs in immunotherapy have shown promise in HCC treatment, particularly with immune checkpoint inhibitors (ICIs). However, the response rate to ICIs is currently limited to approximately 15%-20% of HCC patients. Recently, ICIs demonstrated greater efficacy in "hot" tumors, highlighting the urgency to devise more effective approaches to transform "cold" tumors into "hot" tumors, thereby enhancing the therapeutic potential of ICIs. This review presented an updated summary of the factors influencing the effectiveness of immunotherapy in HCC treatment, identified potential combination therapies that may improve patient response rates to ICIs, and offered an overview of ongoing clinical trials focusing on ICI-based combination therapy.

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.

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.

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.

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.

Current insights into the hepatic microenvironment and advances in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and shows high global incidence and mortality rates. The liver is an immune-tolerated organ with a specific immune microenvironment that causes traditional therapeutic approaches to HCC, such as chemotherapy, radiotherapy, and molecular targeted therapy, to have limited efficacy. The dramatic advances in immuno-oncology in the past few decades have modified the paradigm of cancer therapy, ushering in the era of immunotherapy. Currently, despite the rapid integration of cancer immunotherapy into clinical practice, some patients still show no response to treatment. Therefore, a rational approach is to target the tumor microenvironment when developing the next generation of immunotherapy. This review aims to provide insights into the hepatic immune microenvironment in HCC and summarize the mechanisms of action and clinical usage of immunotherapeutic options for HCC, including immune checkpoint blockade, adoptive therapy, cytokine therapy, vaccine therapy, and oncolytic virus-based therapy.

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.

Efficacy and safety analysis of transarterial chemoembolization and transarterial radioembolization in advanced hepatocellular carcinoma descending hepatectomy

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world, which is seriously threatening the lives of patients. Due to the rapid development of the disease, patients were in the middle and advanced stages at the time of diagnosis and missed the best time for treatment. With the development of minimally invasive medicine, interventional therapy for advanced HCC has achieved promising results. Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are currently recognized as effective treatments. This study aimed to investigate the clinical value and safety of TACE alone and combined with TACE in the treatment of progression in patients with advanced HCC and to find a breakthrough for the early diagnosis and treatment of patients with advanced HCC.

AIM

To investigate the efficacy and safety of hepatic TACE and TARE in advanced descending hepatectomy.

METHODS

In this study, 218 patients with advanced HCC who were treated in the Zhejiang Provincial People’s Hospital from May 2016 to May 2021 were collected. Of the patients, 119 served as the control group and received hepatic TACE, 99 served as the observation group and were treated with hepatic TACE combined with TARE. The patients in two groups were compared in terms of lesion inactivation, tumor nodule size, lipiodol deposition, serum alpha-fetoprotein (AFP) level in different periods, postoperative complications, 1-year survival rate, and clinical symptoms such as liver pain, fatigue, and abdominal distension, and adverse reactions such as nausea and vomiting.

RESULTS

The observation group and the control group had good efficacy in treatment efficiency, reduction of tumor nodules, reduction of postoperative AFP value, reduction of postoperative complications, and relief of clinical symptoms. In addition, compared with the control group, the treatment efficiency, reduction of tumor nodules, reduction of AFP value, reduction of postoperative complications, and relief of clinical symptoms in the observation group were better than those in the TACE group alone. Patients in the TACE + TARE group had a higher 1-year survival rate after surgery, lipiodol deposition was significantly increased and the extent of tumor necrosis was expanded. The overall incidence of adverse reactions in the TACE + TARE group was lower than that in the TACE group, and the difference had statistical significance (P < 0.05).

CONCLUSION

Compared with TACE alone, TACE combined with TARE is more effective in the treatment of patients with advanced HCC. It also improves postoperative survival rate, reduces adverse effects, and has a better safety profile.

Combining Immunotherapy with Transarterial Radioembolization

Hepatocellular carcinoma (HCC) has a high mortality rate due to the diagnosis of patients at advanced stages and ineffective systemic therapies. Immunotherapy is considered a new treatment option for unresectable HCC alternatives to the limitations of conventional cytotoxic chemotherapy. In this case report, we reported that transarterial radioembolization and immunotherapy such as atezolizumab and bevacizumab can be used together in a manner effectively in the management of HCC treatment.

Immunotherapy for advanced or recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with high morbidity and mortality, and is prone to intra- and extrahepatic metastasis due to the anatomical and functional characteristics of the liver. Due to the complexity and high relapse rate associated with radical surgery or radiofrequency ablation, immune checkpoint inhibitors (ICIs) are increasingly being used to treat HCC. Several immunotherapeutic agents, along with their combinations, have been clinically approved to treat advanced or recurrent HCC. This review discusses the leading ICIs in practice and those currently undergoing randomized phase 1–3 trials as monotherapy or combination therapy. Furthermore, we summarize the rapidly developing alternative strategies such as chimeric antigen receptor-engineered T cell therapy and tumor vaccines. Combination therapy is a promising potential treatment option. These immunotherapies are also summarized in this review, which provides insights into the advantages, limitations, and novel angles for future research in establishing viable and alternative therapies against HCC.

Combined Loco-Regional and Systemic Treatment Strategies for Hepatocellular Carcinoma: From Basics to New Developments

Recent advances in systemic therapeutic options have led to improved survival in patients with advanced hepatocellular carcinoma. In order to optimize patient outcomes across different disease stages, attempts are being made at exploiting combinations of loco-regional treatments and systemic therapeutic regimens. The possibilities of a beneficial synergistic effect are strongly supported by biological evidence of changes in tumor microenvironment and systemic immunity. With the advent of newer interventional technologies and newer biological and immunological drugs, these possibilities keep on gaining interest and expectations, yet many questions remain unanswered as to how to best manipulate and combine the two therapeutic approaches.This review aims at providing a general overview of biological foundations, preliminary clinical applications, critical issues and future directions of this constantly growing field.

Sequential transarterial chemoembolisation and stereotactic body radiotherapy followed by immunotherapy as conversion therapy for patients with locally advanced, unresectable hepatocellular carcinoma (START-FIT): a single-arm, phase 2 trial

BACKGROUND

The synergy between locoregional therapies and immune checkpoint inhibitors has not been investigated as conversion therapy for unresectable hepatocellular carcinoma. We aimed to investigate the activity of sequential transarterial chemoembolisation (TACE) and stereotactic body radiotherapy followed by avelumab (an anti-PD-L1 drug) for locally advanced, unresectable hepatocellular carcinoma.

METHODS

START-FIT was a single-arm, phase 2 trial in patients with locally advanced hepatocellular carcinoma who were not suitable for curative treatment, conducted in two hospitals in Hong Kong and one in Shenzhen, China. Eligible patients were those aged 18 years or older with an Eastern Cooperative Oncology Group performance status 0-1, Child-Pugh liver function score A5 to B7, tumour size of at least 5 cm, a maximum of three tumour lesions, and adequate hepatic, renal, and bone marrow function. Participants received TACE on day 1, followed by stereotactic body radiotherapy (27·5-40·0 Gy in five fractions) at day 28. Avelumab (10 mg/kg) was administered 14 days following stereotactic body radiotherapy and every 2 weeks thereafter. The primary endpoint was the proportion of patients deemed amenable to curative treatment, defined as those who had a sustained complete or partial treatment response for at least 2 months and if curative treatment could be performed (ie, resection, radiofrequency ablation, or transplantation), analysed by intention to treat. Safety was also analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT03817736) and has been completed.

FINDINGS

Between March 18, 2019, and Jan 27, 2021, 33 patients (32 [97%] men and one [3%] woman) were enrolled. The median sum of the largest diameters of lesions was 15·1 cm (IQR 8·3-14·9). 21 (64%) patients had macrovascular invasion (hepatic vein [n=13], branched portal vein [n=3], or both [n=5]). Median follow-up was 17·2 months (IQR 7·8-25·8). 18 (55%) patients were deemed amenable to curative treatment: four (12%) of 33 patients had curative treatment (resection [n=2] or radiofrequency ablation [n=2]), and 14 (42%) had a radiological complete response and opted for close surveillance. 11 (33%) of 33 patients had treatment-related adverse events that were grade 3 or worse. The most common treatment-related grade 3 or worse adverse event was transient increase in alanine aminotransferase or aspartate aminotransferase (five [15%]) after TACE. Five (15%) patients developed immune-related adverse events of grade 3 or worse (three had hepatitis, two had dermatitis).

INTERPRETATION

To our knowledge, this is the first prospective trial using the combination of immunotherapy and locoregional treatment as conversion therapy for locally advanced unresectable hepatocellular carcinoma, with promising results. Future randomised trials with larger cohorts of patients are warranted.

FUNDING

Merck.

Immunotherapy in hepatocellular carcinoma

Hepatocellular carcinoma is a highly prevalent tumor worldwide and when it reaches an advanced stage, few systemic treatments are available to improve the survival of these patients. However, greater knowledge about the tumor microenvironment and the role of the immune system in the control of tumor progression has allowed the development of treatments targeting immune checkpoints, which result in encouraging tumor response rates and prolonged survival. Although most of these treatments are well tolerated, up to 20 % of patients may experience side effects derived from non-specific stimulation of the immune system. In the cirrhotic patient, the early diagnosis and treatment of such adverse events is particularly challenging. Therefore, the ongoing investigation on the use of these new therapies will allow us to better understand the profile of the patients who will benefit most.

Nivolumab after selective internal radiation therapy for the treatment of hepatocellular carcinoma: a phase 2, single-arm study

PURPOSE

To evaluate the safety and efficacy of selective internal radiation therapy (SIRT) in combination with a PD-1 inhibitor in patients with unresectable hepatocellular carcinoma (uHCC) and liver-only disease ineligible for chemoembolization.

PATIENTS AND METHODS

NASIR-HCC is a single-arm, multicenter, open-label, phase 2 trial that recruited from 2017 to 2019 patients who were naïve to immunotherapy and had tumors in the BCLC B2 substage (single or multiple tumors beyond the up-to-7 rule), or unilobar tumors with segmental or lobar portal vein invasion (PVI); no extrahepatic spread; and preserved liver function. Patients received SIRT followed 3 weeks later by nivolumab (240 mg every 2 weeks) for up to 24 doses or until disease progression or unacceptable toxicity. Safety was the primary endpoint. Secondary objectives included objective response rate (ORR), time to progression (TTP), and overall survival (OS).

RESULTS

42 patients received SIRT (31 BCLC-B2, 11 with PVI) and were followed for a median of 22.2 months. 27 patients discontinued and 1 never received Nivolumab. 41 patients had any-grade adverse events (AE) and 21 had serious AEs (SAE). Treatment-related AEs and SAEs grade 3-4 occurred in 8 and 5 patients, respectively. Using RECIST 1.1 criteria, ORR reported by investigators was 41.5% (95% CI 26.3% to 57.9%). Four patients were downstaged to partial hepatectomy. Median TTP was 8.8 months (95% CI 7.0 to 10.5) and median OS was 20.9 months (95% CI 17.7 to 24.1).

CONCLUSIONS

The combination of SIRT and nivolumab has shown an acceptable safety profile and signs of antitumor activity in the treatment of patients with uHCC that were fit for SIRT.

TRIAL REGISTRATION NUMBER

NCT03380130.

Addition of Y-90 radioembolization increases tumor response and local disease control in hepatocellular carcinoma patients receiving sorafenib

PURPOSE

To compare the treatment response and progression-free survival (PFS) in advanced hepatocellular carcinoma (HCC) patients who received sorafenib treatment either alone or combined with radioembolization (RE).

METHODS

Follow-up images of the patients treated within a multicenter phase II trial (SORAMIC) were assessed by mRECIST. A total of 177 patients (73 combination arm [RE + sorafenib] and 104 sorafenib arm) were included in this post-hoc analysis. Response and progression characteristics were compared between treatment arms. Survival analyses were done to compare PFS and post-progression survival between treatment arms. Multivariate Cox regression analysis was used to compare survival with factors known to influence PFS in patients with HCC.

RESULTS

The combination arm had significantly higher objective response rate (61.6% vs. 29.8%, p < 0.001), complete response rate (13.7% vs. 3.8%, p = 0.022), and a trend for higher disease control rate (79.2% vs. 72.1%, p = 0.075). Progression was encountered in 116 (65.5%) patients and was more common in the sorafenib arm (75% vs. 52.0%, p = 0.001). PFS (median 8.9 vs. 5.4 months, p = 0.022) and hepatic PFS were significantly better in the combination arm (9.0 vs. 5.7 months, p = 0.014). Multivariate analysis confirmed the treatment arm as an independent predictor of PFS.

CONCLUSION

In advanced HCC patients receiving sorafenib, combination with RE has an additive anticancer effect on sorafenib treatment resulting in a higher and longer tumor response. However, the enhanced response did not translate into prolonged survival. Better patient selection and superselective treatment could improve outcomes after combination therapy.