Immunologic Correlates of Pathologic Complete Response to Preoperative Immunotherapy in Hepatocellular Carcinoma

Treatment Options for Hepatocellular Carcinoma Using Immunotherapy: Present and Future

Hepatocellular carcinoma (HCC) is a common cancer, and the body's immune responses greatly affect its progression and the prognosis of patients. Immunological suppression and the maintenance of self-tolerance in the tumor microenvironment are essential responses, and these form part of the theoretical foundations of immunotherapy. In this review, we first discuss the tumor microenvironment of HCC, describe immunosuppression in HCC, and review the major biomarkers used to track HCC progression and response to treatment. We then examine antibody-based therapies, with a focus on immune checkpoint inhibitors (ICIs), monoclonal antibodies that target key proteins in the immune response (programmed cell death protein 1, anti-cytotoxic T-lymphocyte associated protein 4, and programmed death-ligand 1) which have transformed the treatment of HCC and other cancers. ICIs may be used alone or in conjunction with various targeted therapies for patients with advanced HCC who are receiving first-line treatments or subsequent treatments. We also discuss the use of different cellular immunotherapies, including T cell receptor (TCR) T cell therapy and chimeric antigen receptor (CAR) T cell therapy. We then review the use of HCC vaccines, adjuvant immunotherapy, and oncolytic virotherapy, and describe the goals of future research in the development of treatments for HCC.

Resection of unresectable hepatocellular carcinoma after conversion therapy with apatinib and camrelizumab: a case report and literature review

Hepatocellular carcinoma is a rather common malignant tumor. Most patients with hepatocellular carcinoma receive their diagnosis at an advanced stage, at which surgical resection is no longer appropriate. A growing body of research has demonstrated the value of convention therapy for patients with intermediate-stage hepatocellular carcinoma, while specific application protocols and treatment guidelines are not well developed. Emerging clinical researches suggest that a tyrosine kinase inhibitor in combination with an immune checkpoint inhibitor is a reasonable strategy for unresectable hepatocellular carcinoma. However, there are relatively few reports on the efficacy of apatinib and camrelizumab in the treatment of hepatocellular carcinoma. We were able to successfully remove one patient's hepatocellular carcinoma after 8 cycles of conversion therapy with apatinib (250 mg orally every day) and camrelizumab (200 mg intravenously every 2 weeks). The patient continued to receive the same dose of 16 cycles of apatinib and camrelizumab after hepatectomy. By the time of this study, the patient has completed 18 months of follow-up, and no tumor recurrence or metastasis was found in tumor markers and imaging examinations. Apatinib in combination with camrelizumab is an effective therapy for the treatment of advanced hepatocellular carcinoma, and surgical resection after this conversion therapy may provide patients with long-term oncological benefits. However, this requires more samples to validate the conclusion.

Durvalumab and tremelimumab before surgery in patients with hormone receptor positive, HER2-negative stage II-III breast cancer

A clinical trial was conducted to assess the feasibility of enrolling patients with Stage II or III hormone receptor positive (HR+)/HER2-negative breast cancer to pre-operative dual PD-L1/CTLA-4 checkpoint inhibition administered prior to neoadjuvant chemotherapy (NACT). Eight eligible patients were treated with upfront durvalumab and tremelimumab for two cycles. Patients then received NACT prior to breast surgery. Seven patients had baseline and interval breast ultrasounds after combination immunotherapy and the responses were mixed: 3/7 patients experienced a ≥30% decrease in tumor volume, 3/7 a ≥30% increase, and 1 patient had stable disease. At the time of breast surgery, 1/8 patients had a pathologic complete response (pCR). The trial was stopped early after 3 of 8 patients experienced immunotherapy-related toxicity or suspected disease progression that prompted discontinuation or a delay in the administration of NACT. Two patients experienced grade 3 immune-related adverse events (1 with colitis, 1 with endocrinopathy). Analysis of the tumor microenvironment after combination immunotherapy did not show a significant change in immune cell subsets from baseline. There was limited benefit for dual checkpoint blockade administered prior to NACT in our study of 8 patients with HR+/HER2-negative breast cancer.

Modified integrated tumor burden, liver function, systemic inflammation, and tumor biology score to predict long-term outcomes after resection for hepatocellular carcinoma

BACKGROUND

A preoperative predictive score for hepatocellular carcinoma (HCC) can help stratify patients who undergo resection relative to long-term outcomes and tailor treatment strategies.

METHODS

Patients who underwent curative-intent hepatectomy for HCC between 2000 and 2020 were identified from an international multi-institutional database. A risk score (mFIBA) was developed using an Eastern cohort and then validated using a Western cohort.

RESULTS

Among 957 patients, 443 and 514 patients were included from the Eastern and Western cohorts, respectively. On multivariable analysis, alpha-feto protein (HR1.97, 95%CI 1.42-2.72), neutrophil-to-lymphocyte ratio (HR1.74, 95%CI 1.28-2.38), albumin-bilirubin grade (HR1.66, 95%CI 1.21-2.28), and imaging tumor burden score (HR1.25, 95%CI 1.12-1.40) were associated with OS. The c-index in the Eastern test and Western validation cohorts were 0.69 and 0.67, respectively. Notably, mFIBA score outperformed previous HCC staging systems. 5-year OS incrementally decreased with an increase in mFIBA. On multivariable Cox regression analysis, the mFIBA score was associated with worse OS (HR1.18, 95%CI 1.13-1.23) and higher risk of recurrence (HR1.16, 95%CI 1.11-1.20). An easy-to-use calculator of the mFIBA score was made available online (https://yutaka-endo.shinyapps.io/mFIBA_score/).

DISCUSSION

The online mFIBA calculator may help surgeons with clinical decision-making to individualize perioperative treatment strategies for patients undergoing resection of HCC.

Biomarkers for immunotherapy of hepatocellular carcinoma

Immune-checkpoint inhibitors (ICIs) are now widely used for the treatment of patients with advanced-stage hepatocellular carcinoma (HCC). Two different ICI-containing regimens, atezolizumab plus bevacizumab and tremelimumab plus durvalumab, are now approved standard-of-care first-line therapies in this setting. However, and despite substantial improvements in survival outcomes relative to sorafenib, most patients with advanced-stage HCC do not derive durable benefit from these regimens. Advances in genome sequencing including the use of single-cell RNA sequencing (both of tumour material and blood samples), as well as immune cell identification strategies and other techniques such as radiomics and analysis of the microbiota, have created considerable potential for the identification of novel predictive biomarkers enabling the accurate selection of patients who are most likely to derive benefit from ICIs. In this Review, we summarize data on the immunology of HCC and the outcomes in patients receiving ICIs for the treatment of this disease. We then provide an overview of current biomarker use and developments in the past 5 years, including gene signatures, circulating tumour cells, high-dimensional flow cytometry, single-cell RNA sequencing as well as approaches involving the microbiome, radiomics and clinical markers. Novel concepts for further biomarker development in HCC are then discussed including biomarker-driven trials, spatial transcriptomics and integrated 'big data' analysis approaches. These concepts all have the potential to better identify patients who are most likely to benefit from ICIs and to promote the development of new treatment approaches.

Real-World Use of Immunotherapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide and accounts for 90% of all primary liver cancers. Chronic inflammation is the hallmark across most prevalent etiologies among which HBV is the leading cause worldwide (33%), followed by alcohol (30%), HCV (21%), other factors like non-alcoholic steatohepatitis linked to insulin resistance/metabolic syndrome, and obesity associated inflammation (16%). Deregulation of the tightly controlled immunological network leads to liver disease, including chronic infection, autoimmunity, and tumor development. While inflammation drives oncogenesis in the liver, HCC also recruits ICOS+ FOXP3+ Tregs and MDSCs and upregulates immune checkpoints to induce a state of immunosuppression in the tumor microenvironment. As such, research is focused on targeting and modulating the immune system to treat HCC. The Checkmate 040 and Keynote 224 studies established the role of immunotherapy in the treatment of patients with HCC. In Phase I and II trials, nivolumab and pembrolizumab demonstrated durable response rates of 15-20% and were subsequently approved as second-line agents after sorafenib. Due to the success of the IMbrave 150 and HIMALAYA trials, which examined the combination of atezolizumab/bevacizumab and tremelimumab/durvalumab, respectively, the FDA approved these regimens as first-time treatment options for patients with advanced HCC. The encouraging results of immunotherapy in the management of HCC has led researchers to evaluate if combination with locoregional therapies may result in a synergistic effect. Real-world studies represent an invaluable tool to assess and verify the applicability of clinical trials in the bedside setting with a more varied patient population. We herein review current real-life use of ICIs in the management of HCC and highlight some of the ongoing clinical trials that are expected to change current recommended first-line treatment in the near future.

Case Report: A case of hepatocellular carcinoma with aberrant right hepatic artery treated with transarterial chemoembolization and infusion chemotherapy separately to bilobar lesion combining with systemic therapies and sequential hepatectomy

Background

Hepatocellular carcinoma (HCC) with a dismal prognosis is the second most deadly malignancy globally. Surgery is believed to be a curative approach. Nevertheless, there is still a considerable probability of postoperative recurrence. Most patients present in advanced stages with a surgically and oncologically unresectable disease. Systemic medicines are increasingly important to downstage the disease and further improve survival.

Case summary

A 67-year-old Chinese man with uncontrolled hepatitis B was discovered to have liver masses with abnormal serum vitamin K absence or antagonist-II (PIVKA-II) level during checkup for upper abdominal discomfort. Abdominal multiphase computerized tomography (CT) and gadoxetate disodium-enhanced magnetic resonance imaging (MRI) showed the bulky bilobar HCCs of Barcelona Clinic Liver Cancer stage B and China Liver Cancer Staging stage IIa. Furthermore, the aberrant right hepatic artery (RHA) originates from the superior mesenteric artery. Due to the location being adjacent to important vasculatures and massive size of the right-sided lesion, curative resection appears to be challenging. To achieve a favorable surgical margin, repeated hepatic arterial infusion chemotherapy (HAIC) was adopted through the variant RHA, while transarterial chemoembolization (TACE) was delivered to the left lobe to arrest tumor growth. Furthermore, sintilimab plus lenvatinib served as the sequential systemic therapy. After 5 months of conversion treatment, the partial response with a decreased serum PIVKA-II level was attained. The R0 hepatectomy was then performed without postoperative complications. The immunohistochemistry and next-generation sequencing results suggested that the two-side HCCs existing tumor heterogeneity were not completely consistent. The patient continues to be without evidence of disease.

Conclusion

Our case highlights a favorable outcome in a man with bilobar bulky HCC after undergoing the comprehensive therapeutic schedule that includes personalized intervention and systemic drug therapy. In terms of conversion therapy, our case provides a secure and practical reference for managing unresectable bilobar HCC coexisting with the aberrant hepatic artery.

Immunotherapies in non-metastatic gastrointestinal cancers

PURPOSE

Over the last decade, immune checkpoint inhibitors (ICI) have emerged as cornerstone in the treatment of many metastatic tumour types, including gastrointestinal cancers. In many solid tumours, the effective therapies in the metastatic field are progressively brought into the curative setting. Consequently, earlier tumoural settings have become a field of experiment for immunotherapies. In melanoma, lung, and bladder cancers, excellent results were recorded, possibly explained by differences in the tumour microenvironment between metastatic and non-metastatic settings. In gastrointestinal (GI) Oncology, nivolumab is the first immune checkpoint inhibitor to become a standard-of-care adjuvant treatment after curative surgery for oesophagal or gastroesophageal junction cancer.

RECENT FINDINGS

We herein discuss the results of a selection of the most relevant studies presented/published over the last 18 months testing immunotherapies in non-metastatic GI cancers. Among immunotherapies, ICI have been investigated in pre-, peri- and postoperative setting across tumour types, alone or in combination with chemo- and/or radiotherapy. Vaccines are also a new field of investigation.

SUMMARY

Promising results from two studies (NCT04165772 and NICHE-2 study) demonstrating never-seen-before responses to neoadjuvant immunotherapy in MMR deficient (dMMR) colorectal cancers raise hope for improving the patients' outcome and developing organ-sparing strategies in this situation.

Nivolumab plus ipilimumab combination therapy in cancer: Current evidence to date

Immune checkpoint inhibitors (ICIs) have revolutionized cancer immunotherapy, yielding significant antitumor responses across multiple cancer types. Combination ICI therapy with anti-CTLA-4 and anti-PD-1 antibodies outperforms either antibody alone in terms of clinical efficacy. As a consequence, the U.S. Food and Drug Administration (FDA) approved ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) as the first-ever approved therapies for combined ICI in patients with metastatic melanoma. Despite the success of ICIs, treatment with checkpoint inhibitor combinations poses significant clinical challenges, such as increased rates of immune-related adverse events (irAEs) and drug resistance. Thus, identifying optimal prognostic biomarkers could help to monitor the safety and efficacy of ICIs and identify patients who may benefit the most from these treatments. In this review, we will first go over the fundamentals of the CTLA-4 and PD-1 pathways, as well as the mechanisms of ICI resistance. The results of clinical findings that evaluated the combination of ipilimumab and nivolumab are then summarized to support future research in the field of combination therapy. Finally, the irAEs associated with combined ICI therapy, as well as the underlying biomarkers involved in their management, are discussed.

Immunotherapy for hepatocellular carcinoma: Recent advances and future targets

Immunotherapy is a promising approach to treating various types of cancers, including hepatocellular carcinoma (HCC). While single immunotherapy drugs show limited effectiveness on a small subset of patients, the combination of the anti PD-L1 atezolizumab and anti-vascular endothelial growth factor bevacizumab has shown significant improvement in survival compared to sorafenib as a first-line treatment. However, the current treatment options still have a low success rate of about 30%. Thus, more effective treatments for HCC are urgently required. Several novel immunotherapeutic methods, including the use of novel immune checkpoint inhibitors, innovative immune cell therapies like chimeric antigen receptor T cells (CAR-T), TCR gene-modified T cells and stem cells, as well as combination strategies are being tested in clinical trials for the treatment of HCC. However, some crucial issues still exist such as the presence of heterogeneous antigens in solid tumors, the immune-suppressive environment within tumors, the risk of on-target/off-tumor, infiltrating CAR-T cells, immunosuppressive checkpoint molecules, and cytokines. Overall, immunotherapy is on the brink of major advancements in the fight against HCC.

Preoperative risk score (PreopScore) to predict overall survival after resection for hepatocellular carcinoma

BACKGROUND

This study aimed to develop a holistic risk score incorporating preoperative tumor, liver, nutritional, and inflammatory markers to predict overall survival (OS) after hepatectomy for hepatocellular carcinoma (HCC).

METHODS

Patients who underwent curative-intent surgery for HCC between 2000 and 2020 were identified using an international multi-institutional database. Preoperative predictors associated with OS were selected and a prognostic risk score model (PreopScore) was developed and validated using cross-validation.

RESULTS

A total of 1676 patients were included. On multivariable analysis, preoperative parameters associated with OS included α-feto protein (hazard ratio [HR]1.17, 95%CI 1.03-1.34), neutrophil-to-lymphocyte ratio (HR2.62, 95%CI 1.30-5.30), albumin (HR0.49, 95%CI 0.34-0.70), gamma-glutamyl transpeptidase (HR1.00, 95%CI 1.00-1.00), as well as vascular involvement (HR3.52, 95%CI 2.10-5.89) and tumor burden score (medium, HR3.49, 95%CI 1.62-7.58; high, HR3.21, 95%CI 1.40-7.35) on preoperative imaging. A weighted PreopScore was devised and made available online (https://yutaka-endo.shinyapps.io/PrepoScore_Shiny/). Patients with a PreopScore 0-2, 2-3.5, and >3.5 had incrementally worse 5-year OS of 85.8%, 70.7%, and 52.4%, respectively (p < 0.001). The c-index of the test and validation cohort were 0.75 and 0.71, respectively. The PreopScore outperformed individual parameters and previous HCC staging systems.

DISCUSSION

The PreopScore can be used as a better guide to preoperatively identify patients and individualize pre-/post-operative strategies.

Society for Immunotherapy of Cancer (SITC) consensus definitions for resistance to combinations of immune checkpoint inhibitors

Immunotherapy is the standard of care for several cancers and the field continues to advance at a rapid pace, with novel combinations leading to indications in an increasing number of disease settings. Durable responses and long-term survival with immunotherapy have been demonstrated in some patients, though lack of initial benefit and recurrence after extended disease control remain major hurdles for the field. Many new combination regimens are in development for patients whose disease progressed on initial immunotherapy. To guide clinical trial design and support analyses of emerging molecular and cellular data surrounding mechanisms of resistance, the Society for Immunotherapy of Cancer (SITC) previously generated consensus clinical definitions for resistance to single-agent anti-PD-1 immune checkpoint inhibitors (ICIs) in three distinct scenarios: primary resistance, secondary resistance, and progression after treatment discontinuation. An unmet need still exists, however, for definitions of resistance to ICI-based combinations, which represent an expanding frontier in the immunotherapy treatment landscape. In 2021, SITC convened a workshop including stakeholders from academia, industry, and government to develop consensus definitions for resistance to ICI-based combination regimens for improved outcome assessment, trial design and drug development. This manuscript reports the minimum drug exposure requirements and time frame for progression that define resistance in both the metastatic setting and the perioperative setting, as well as key caveats and areas for future research with ICI/ICI combinations. Definitions for resistance to ICIs in combination with chemotherapy and targeted therapy will be published in companion volumes to this paper.

Hepatocellular Carcinoma: New Developments

This is a review of current practices and upcoming developments regarding hepatocellular carcinoma (HCC). This includes a contemporary review of the diagnosis, staging, and treatment of HCC. Furthermore, the authors provide a review of certain ongoing trials and future directions of various treatment modalities for HCC.

Recent progress in cancer immunotherapy: Overview of current status and challenges

Cancer treatment is presently one of the most important challenges in medical science. Surgery, chemotherapy, radiotherapy, or combining these methods is used to eliminate the tumor. Hormone therapy, bone marrow transplantation, stem cell therapy as well as immunotherapy are other well-known therapeutic modalities. Immunotherapy, as the most important complementary method, uses the immune system for treating cancer followed by surgery, chemotherapy, and radiotherapy. This method is systematically used to prevent malignancies development mainly via potentiating antitumor immune cells activation and conversely compromising their exhaustion with the lowest negative effects on healthy cells. Active immunotherapy can be employed for cancer immunotherapy by directly using the ingredients of the immune system and activating immune responses. On the other hand, inactive immunotherapy is utilized by indirect induction and using immune cell-based products consisting of monoclonal antibodies. It has strongly been proved that combination therapy with immunotherapies and other therapeutic means, such as anti-angiogenic agents, could be a rational plan to treat cancer. Herein, we have focused on recent findings concerning the therapeutic merits of cancer therapy using immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and cancer vaccine alone or in combination with other approaches. Also, we offer a glimpse into the current challenges in this context.

Systemic therapies in hepatocellular carcinoma: Existing and emerging biomarkers for treatment response

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the third most common cause of cancer-related death worldwide. Due to asymptomatic patients in the early stage, most patients are diagnosed at an advanced stage and lose the opportunity for radical resection. In addition, for patients who underwent procedures with curative intent for early-stage HCC, up to 70% of patients may have disease recurrence within 5 years. With the advent of an increasing number of systemic therapy medications, we now have more options for the treatment of HCC. However, data from clinical studies show that with different combinations of regimens, the objective response rate is approximately 40%, and most patients will not respond to treatment. In this setting, biomarkers for predicting treatment response are of great significance for precise treatment, reducing drug side effects and saving medical resources. In this review, we summarized the existing and emerging biomarkers in the literature, with special emphasis on the pathways and mechanism underlying the prediction value of those biomarkers for systemic treatment response.

Role of immunotherapy in downsizing hepatocellular carcinoma prior to liver transplantation

Hepatocellular carcinoma (HCC) is an aggressive primary liver neoplasm that, according to tumor stage, can be treated with resection, transplantation, locoregional treatment options, or systemic therapy. Although interventions only in early-stage disease can offer complete tumor regression, systemic therapy in advanced disease can significantly prolong overall survival, according to published clinical trials. The emergence of immunotherapy in the field of cancer therapy has had a positive impact on patients with HCC, resulting in atezolizumab–bevacizumab currently being the first-line option for treatment of advanced HCC. In light of this, application of immunotherapy in the preoperative process could increase the number of patients fulfilling the criteria for liver transplantation (LT). Implementation of this approach is faced with challenges regarding the safety of immunotherapy and the possibly increased risk of rejection in the perioperative period. Case reports and clinical trials assessing the safety profile and effectiveness of neoadjuvant immunotherapy, highlight important aspects regarding this newly evolving approach to HCC management. More studies need to be conducted in order to reach a consensus regarding the optimal way to administer immunotherapy prior to LT. In this review, we summarize the role, safety profile and future considerations regarding the use of neoadjuvant immunotherapy prior to LT in patients with HCC.

Tertiary lymphoid structures: Associated multiple immune cells and analysis their formation in hepatocellular carcinoma

The prognostic value of immune cells in tertiary lymphoid structures (TLSs) remains unclear in hepatocellular carcinoma (HCC). Here, 59 of 145 patients had TLSs in training set, 48 of 120 patients had TLSs in testing set. Immunohistochemistry (IHC) were used to label CD3+ T cells, CD20+ B cells, CD8+ T cells, CD208+ dendritic cells, and CD21+ follicular dendritic cells in TLSs. High CD20+, CD208+, and CD8+ cell densities were favorable prognostic factors for overall survival (OS). High CD3+, CD20+, CD208+, and CD8+ cell densities were significantly associated with reduced early recurrence. TLSs were divided into three grades (A, B, and C) based on immune cell density. Patients with grade C or B had significantly improved OS. Patients with grade C had the lowest recurrence rate, followed by those with grade B, while patients with grade A had the highest recurrence rate. The stromal, immune, and ESTIMATE scores derived from the ESTIMATE package were significantly higher and tumor purity was significantly lower in patients with TLSs. Patients with TLSs had significantly higher relative numbers of memory B cells, plasma cells, CD8+ T cells, NK cells, and dendritic cells and lower relative numbers of Treg cells, macrophages, and M2 macrophages according to the CIBERSORT assessment. Bioinformatics analysis and experiments confirmed that KLRK1 and GZMA expression are associated TLSs formation and can predict TLSs existence. Grade B and grade C were favorable prognostic factors for OS and recurrence and could represent immune-active tumors.

Virtual clinical trials of anti-PD-1 and anti-CTLA-4 immunotherapy in advanced hepatocellular carcinoma using a quantitative systems pharmacology model

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and is the third-leading cause of cancer-related death worldwide. Most patients with HCC are diagnosed at an advanced stage, and the median survival for patients with advanced HCC treated with modern systemic therapy is less than 2 years. This leaves the advanced stage patients with limited treatment options. Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) or its ligand, are widely used in the treatment of HCC and are associated with durable responses in a subset of patients. ICIs targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) also have clinical activity in HCC. Combination therapy of nivolumab (anti-PD-1) and ipilimumab (anti-CTLA-4) is the first treatment option for HCC to be approved by Food and Drug Administration that targets more than one immune checkpoints.

METHODS

In this study, we used the framework of quantitative systems pharmacology (QSP) to perform a virtual clinical trial for nivolumab and ipilimumab in HCC patients. Our model incorporates detailed biological mechanisms of interactions of immune cells and cancer cells leading to antitumor response. To conduct virtual clinical trial, we generate virtual patient from a cohort of 5,000 proposed patients by extending recent algorithms from literature. The model was calibrated using the data of the clinical trial CheckMate 040 (ClinicalTrials.gov number, NCT01658878).

RESULTS

Retrospective analyses were performed for different immune checkpoint therapies as performed in CheckMate 040. Using machine learning approach, we predict the importance of potential biomarkers for immune blockade therapies.

CONCLUSIONS

This is the first QSP model for HCC with ICIs and the predictions are consistent with clinically observed outcomes. This study demonstrates that using a mechanistic understanding of the underlying pathophysiology, QSP models can facilitate patient selection and design clinical trials with improved success.

Hepatocellular carcinoma downstaging for liver transplantation in the era of systemic combined therapy with anti-VEGF/TKI and immunotherapy

Hepatocellular carcinoma remains a global health challenge affecting close to 1 million cases yearly. Liver transplantation provides the best long-term outcomes for those meeting strict criteria. Efforts have been made to expand these criteria, whereas others have attempted downstaging approaches. Although locoregional approaches to downstaging are appealing and have demonstrated efficacy, limitations and challenges exists including poor imaging modality to assess response and appropriate endpoints along the process. Recent advances in systemic treatments including immune checkpoint inhibitors alone or in combination with tyrosine kinase inhibitors have prompted the discussion regarding their role for downstaging disease prior to transplantation. Here, we provide a review of prior locoregional approaches for downstaging, new systemic agents and their role for downstaging, and finally, key and critical considerations of the assessment, endpoints, and optimal designs in clinical trials to address this key question.

Role of interventional oncology in hepatocellular carcinoma: Future best practice beyond current guidelines

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths globally. Liver transplant remains the goal of curative treatment, but limited supply of organs decreases accessibility and prolongs waiting time to transplantation. Therefore, interventional oncology therapies have been used to treat the majority of HCC patients, including those awaiting transplant. The Barcelona Clinic Liver Cancer (BCLC) classification is the most widely used staging system in management of HCC that helps allocate treatments. Since its inception in 1999, it was updated for the fifth time in November 2021 and for the first time shaped by expert opinions outside the core BCLC group. The most recent version includes additional options for early-stage disease, substratifies intermediate disease into three groups, and lists alternates to Sorafenib that can double the expected survival of advanced-stage disease. The group also proposed a new BCLC staging schema for disease progression, and endorsed treatment stage migration (TSM) directly into the main staging and treatment algorithm. This article reviews the recent developments underlying the current BCLC guidelines and highlights ongoing research, particularly involving radioembolization, that will shape future best practice.

Neoadjuvant Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is characterized by low resection and high postoperative recurrence rates, and conventional treatment strategies have failed to meet clinical needs. Neoadjuvant therapy (NAT) is widely employed in the routine management of several solid tumors because it increases resectability and reduces the rate of postoperative recurrence. However, a consensus has not been reached regarding the effects of NAT on HCC. As systemic therapy, particularly targeted therapy and immunotherapy, is given for HCC treatment, accumulating evidence shows that the “spring” of NAT for HCC is imminent. In the future, HCC researchers should focus on identifying biomarkers for treatment response, explore the mechanisms of resistance, and standardize the endpoints of NAT.

Multimodal predictors for precision immunotherapy

Immune checkpoint blockade (ICB) unleashes immune cells to attack tumors, thereby inducing durable clinical responses in many cancer types. The number of patients responding to ICB is modest, however, and combination treatments are likely needed to overcome the multifaceted suppressive pathways active in the tumor microenvironment (TME). The development of precision immuno-oncology (IO) strategies allowing to identify the optimal treatment of each patient upfront is therefore a pivotal question in the field of cancer immunotherapy. Although single-parameter biomarkers can enrich for response to ICB, their predictive capacity is far from perfect and their clinical utility is complicated by their continuous nature and the difficulty to determine cut-offs that reliably distinguish responding patients from those without clinical benefit. The antitumor immune response that is induced or reinvigorated by immunotherapy is a complex cascade of events requiring the interplay of multiple cell types. To move towards precision IO, it is therefore essential to understand for each individual patient at which level(s) the antitumor immune response failed and how it can be therapeutically restored. Holistic approaches to profile human tumor microenvironments and treatment-induced responses may help to identify critical rate-limiting factors of antitumor immunity. These factors need to be translated into clinically applicable multimodal predictors that allow for the selection of the best IO treatment. This review discusses strategies to (i) create such holistic views of antitumor immunity, (ii) identify measurable parameters capturing the complexity of a patient's immune status, and (iii) facilitate the incorporation of precision IO research in the clinic.

Chinese expert consensus on conversion therapy for hepatocellular carcinoma (2021 edition)

Recent advances in systemic and locoregional treatments for patients with unresectable or advanced hepatocellular carcinoma (HCC) have resulted in improved response rates. This has provided an opportunity for selected patients with initially unresectable HCC to achieve adequate tumor downstaging to undergo surgical resection, a 'conversion therapy' strategy. However, conversion therapy is a new approach to the treatment of HCC and its practice and treatment protocols are still being developed. Review the evidence for conversion therapy in HCC and develop consensus statements to guide clinical practice. Evidence review: Many research centers in China have accumulated significant experience implementing HCC conversion therapy. Preliminary findings and data have shown that conversion therapy represents an important strategy to maximize the survival of selected patients with intermediate stage to advanced HCC; however, there are still many urgent clinical and scientific challenges for this therapeutic strategy and its related fields. In order to summarize and learn from past experience and review current challenges, the Chinese Expert Consensus on Conversion Therapy for Hepatocellular Carcinoma (2021 Edition) was developed based on a review of preliminary experience and clinical data from Chinese and non-Chinese studies in this field and combined with recommendations for clinical practice. Sixteen consensus statements on the implementation of conversion therapy for HCC were developed. The statements generated in this review are based on a review of clinical evidence and real clinical experience and will help guide future progress in conversion therapy for patients with HCC.

Immunotherapies for hepatocellular carcinoma

Liver cancer, more specifically hepatocellular carcinoma (HCC), is the second leading cause of cancer-related death and its incidence is increasing globally. Around 50% of patients with HCC receive systemic therapies, traditionally sorafenib or lenvatinib in the first line and regorafenib, cabozantinib or ramucirumab in the second line. In the past 5 years, immune-checkpoint inhibitors have revolutionized the management of HCC. The combination of atezolizumab and bevacizumab has been shown to improve overall survival relative to sorafenib, resulting in FDA approval of this regimen. More recently, durvalumab plus tremelimumab yielded superior overall survival versus sorafenib and atezolizumab plus cabozantinib yielded superior progression-free survival. In addition, pembrolizumab monotherapy and the combination of nivolumab plus ipilimumab have received FDA Accelerated Approval in the second-line setting based on early efficacy data. Despite these major advances, the molecular underpinnings governing immune responses and evasion remain unclear. The immune microenvironment has crucial roles in the development and progression of HCC and distinct aetiology-dependent immune features have been defined. Inflamed and non-inflamed classes of HCC and genomic signatures have been associated with response to immune-checkpoint inhibitors, yet no validated biomarker is available to guide clinical decision-making. This Review provides information on the immune microenvironments underlying the response or resistance of HCC to immunotherapies. In addition, current evidence from phase III trials on the efficacy, immune-related adverse events and aetiology-dependent mechanisms of response are described. Finally, we discuss emerging trials assessing immunotherapies across all stages of HCC that might change the management of this disease in the near future.

Perioperative nivolumab monotherapy versus nivolumab plus ipilimumab in resectable hepatocellular carcinoma: a randomised, open-label, phase 2 trial

BACKGROUND

Hepatocellular carcinoma has high recurrence rates after surgery; however, there are no approved standard-of-care neoadjuvant or adjuvant therapies. Immunotherapy has been shown to improve survival in advanced hepatocellular carcinoma; we therefore aimed to evaluate the safety and tolerability of perioperative immunotherapy in resectable hepatocellular carcinoma.

METHODS

In this single-centre, randomised, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma were randomly assigned (1:1) to receive 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery at 6 weeks) followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for 2 years, or 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery) plus one dose of 1 mg/kg of ipilimumab intravenously concurrently with the first preoperative dose of nivolumab, followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for up to 2 years plus 1 mg/kg of ipilimumab intravenously every 6 weeks for up to four cycles. Patients were randomly assigned to the treatment groups by use of block randomisation with a random block size. The primary endpoint was the safety and tolerability of nivolumab with or without ipilimumab. Secondary endpoints were the proportion of patients with an overall response, time to progression, and progression-free survival. This trial is registered with ClinicalTrials.gov (NCT03222076) and is completed.

FINDINGS

Between Oct 30, 2017, and Dec 3, 2019, 30 patients were enrolled and 27 were randomly assigned: 13 to nivolumab and 14 to nivolumab plus ipilimumab. Grade 3-4 adverse events were higher with nivolumab plus ipilimumab (six [43%] of 14 patients) than with nivolumab alone (three [23%] of 13). The most common treatment-related adverse events of any grade were increased alanine aminotransferase (three [23%] of 13 patients on nivolumab vs seven [50%] of 14 patients on nivolumab plus ipilimumab) and increased aspartate aminotransferase (three [23%] vs seven [50%]). No patients in either group had their surgery delayed due to grade 3 or worse adverse events. Seven of 27 patients had surgical cancellations, but none was due to treatment-related adverse events. Estimated median progression-free survival was 9·4 months (95% CI 1·47-not estimable [NE]) with nivolumab and 19·53 months (2·33-NE) with nivolumab plus ipilimumab (hazard ratio [HR] 0·99, 95% CI 0·31-2·54); median time to progression was 9·4 months (95% CI 1·47-NE) in the nivolumab group and 19·53 months (2·33-NE) in the nivolumab plus ipilimumab group (HR 0·89, 95% CI 0·31-2·54). In an exploratory analysis, three (23%) of 13 patients had an overall response with nivolumab monotherapy, versus none with nivolumab plus ipilimumab. Three (33%) of nine patients had a major pathological response (ie, ≥70% necrosis in the resected tumour area) with nivolumab monotherapy compared with three (27%) of 11 with nivolumab plus ipilimumab.

INTERPRETATION

Perioperative nivolumab alone and nivolumab plus ipilimumab appears to be safe and feasible in patients with resectable hepatocellular carcinoma. Our findings support further studies of immunotherapy in the perioperative setting in hepatocellular carcinoma.

FUNDING

Bristol Myers Squibb and the US National Institutes of Health.

Immunotherapy in older patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of cancer globally and is currently the third leading cause of cancer-related deaths. Recently, immunotherapy using immune checkpoint inhibitors (ICIs) has been shown with encouraging anticancer activity and safety in clinical trials. To reverse the phenomenon of tumours evading immune response, ICIs can be used to stimulate the natural antitumour potential of cancer cells by blocking the relevant checkpoints to activate T cells. However, the components and functions of the immune system may undergo a series of changes with ageing, known as 'immunosenescence,' potentially affecting the antitumour effect and safety of immunotherapy. In the current phase III clinical trials of ICIs including nivolumab, pembrolizumab and atezolizumab, the proportion of patients with HCC older than 65 years in CheckMate 459, KEYNOTE-240 and IMbrave150 is 51%, 58% and 50%, respectively, which is less than 70%-73% of epidemiological investigation. Therefore, the elderly population recruited in clinical trials may not accurately represent the real-world elderly patients with HCC, which affects the extrapolation of the efficacy and safety profile obtained in clinical trials to the elderly population in the real world. This review provides the latest advances in ICIs immuno-treatment available for HCC and relevant information about their therapeutic effects and safety on elderly patients. We discuss the benefits of ICIs for older HCC patients, and relevant recommendations about conducting further clinical trials are proposed for more complete answers to this clinical issue.

A Novel Nine-lncRNA Risk Signature Correlates With Immunotherapy in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma is one of the most common malignant tumors with a very high mortality rate. The emergence of immunotherapy has brought hope for the cure of hepatocellular carcinoma. Only a small number of patients respond to immune checkpoint inhibitors, and ferroptosis and tertiary lymphoid structure contribute to the increased response rate of immune checkpoint inhibitors; thus, we first need to identify those who are sensitive to immunotherapy and then develop different methods to improve sensitivity for different groups.

Methods

The sequencing data of hepatocellular carcinoma from The Cancer Genome Atlas and Gene Expression Omnibus was downloaded to identify the immune-related long non-coding RNAs (lncRNAs). LncRNAs related to survival data were screened out, and a risk signature was established using Cox proportional hazard regression model. R software was used to calculate the riskScore of each patient, and the patients were divided into high- and low-risk groups. The prognostic value of riskScore and its application in clinical chemotherapeutic drugs were confirmed. The relationship between riskScore and immune checkpoint genes, ferroptosis genes, and genes related to tertiary lymphoid structure formation was analyzed by Spearman method. TIMER, CIBERSORT, ssGSEA, and ImmuCellAI were used to evaluate the relative number of lymphocytes in tumor. The Wilcoxon signed-rank test confirmed differences in immunophenoscore between the high- and low-risk groups.

Results

Data analysis revealed that our signature could well predict the 1-, 2-, 3-, and 5-year survival rates of hepatocellular carcinoma and to predict susceptible populations with Sorafenib. The risk signature were significantly correlated with immune checkpoint genes, ferroptosis genes, and tertiary lymphoid structure-forming genes, and predicted tumor-infiltrating lymphocyte status. There was a significant difference in IPS scores between the low-risk group and the high-risk group, while the low-risk group had higher scores.

Conclusion

The riskScore obtained from an immune-related lncRNA signature could successfully predict the survival time and reflect the efficacy of immune checkpoint inhibitors. More importantly, it is possible to select different treatments for different hepatocellular carcinoma patients that increase the response rate of immune checkpoint inhibitors and will help improve the individualized treatment of hepatocellular carcinoma.

Hepatocellular Carcinoma Immunotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and the third leading cause of cancer-related death worldwide. Single-agent anti-PD-1 immune checkpoint inhibitors (ICIs) demonstrated promising efficacy in early-phase trials, a finding that was not confirmed in phase III studies. The combination of atezolizumab (an anti-PD-L1 ICI) with bevacizumab (an anti-VEGF antibody) was approved as first-line therapy in 2020, however, with significant improvement in response rate, progression-free survival, and overall survival in comparison with the previous standard of care, sorafenib. Numerous ongoing clinical trials are assessing ICIs in combination with each other or with targeted agents, and also in earlier stages with local therapies. This review summarizes the latest concepts in the use of ICIs for the management of HCC. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Current Landscape and Future Directions of Biomarkers for Immunotherapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer and one of the leading causes of cancer-related deaths in the world. Multiple immunotherapeutic approaches have been investigated to date, and immunotherapy has become the new standard of care therapy in HCC. However, the current role of immunotherapy in HCC remains non-curative. Given this context, a high priority for oncology is understanding the biomarkers that predict clinical response to immunotherapy, have the potential to improve patient selection to maximize the clinical benefit, and spare unnecessary toxicity. In this review, we summarize the key predictive and prognostic biomarkers investigated in immunotherapy clinical trials in HCC and the emerging biomarkers to serve as a roadmap for future clinical trials. Biomarkers from tumoral tissues including PDL-1 expression, tissue infiltrating lymphocytes, tumor mutational burden (TMB) and specific immune signatures, and from peripheral blood including neutrophil-to-lymphocytes ratio, platelet-to-lymphocytes ratio, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and specific cytokines, along with gut microbiota are among the studied biomarkers to date in the HCC era. More integrative approaches, including mathematical biomarkers to predict immunotherapy outcomes, are yet to be studied in HCC.

Biomarkers and Future Perspectives for Hepatocellular Carcinoma Immunotherapy

Hepatocellular cancer is the sixth most frequently diagnosed malignant disease worldwide, and was responsible for tens of millions of deaths in 2020; however, treatment options for patients with advanced hepatocellular carcinoma remain limited. Immunotherapy has undergone rapid development over recent years, especially in the field of immune checkpoint inhibitors (ICIs). These drugs aim to activate and enhance antitumor immunity and represent a new prospect for the treatment of patients with advanced cancer. Nevertheless, only a small proportion of liver cancer patients currently benefit from ICI-based treatment, highlighting the need to better understand how ICIs and tumors interact, as well as identify predictive biomarkers for immunotherapeutic responses. In this review, we highlight clinical trials and basic research in hepatocellular carcinoma, with a particular focus on predictive biomarkers for the therapeutic efficacy of ICIs. Predictive biomarkers for immune-related adverse events are also discussed.

Adjuvant versus Neoadjuvant Immunotherapy for Hepatocellular Carcinoma: Clinical and Immunologic Perspectives

Advancement in systemic therapy, particularly immune checkpoint inhibitor (ICI)-based combination regimens, has transformed the treatment landscape for patients with advanced hepatocellular carcinoma (HCC). The advancement in systemic therapy also provides new opportunities of reducing recurrence after curative therapy through adjuvant therapy or improving resectability through neoadjuvant therapy. Improved recurrence-free survival by adjuvant or neoadjuvant ICI-based therapy has been reported in other cancer types. In this article, developments of systemic therapy in adjuvant and neoadjuvant settings for HCC were reviewed. The design of adjuvant and neoadjuvant therapy using ICI-based regimens and potential challenges of trial conduct and result analysis was discussed. Results from these trials may extend the therapeutic benefit of ICI-based systemic therapy beyond the advanced-stage disease and lead to a new era of multidisciplinary management for HCC.

Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors and Applicability of First-Line Atezolizumab/Bevacizumab in a Real-Life Setting

Immune checkpoint inhibitors (ICIs) are the new frontier for the treatment of advanced hepatocellular carcinoma (HCC). Since the first trial with tremelimumab, a cytotoxic T-lymphocyte-associated protein 4 inhibitor, increasing evidence has confirmed that these drugs can significantly extend the survival of patients with advanced hepatocellular carcinoma (HCC). As a matter of fact, the overall survival and objective response rates reported in patients with advanced HCC treated with ICIs are the highest ever reported in the second-line setting and, most recently, the combination of the anti-programmed death ligand protein-1 atezolizumab with bevacizumab-an anti-vascular endothelial growth factor monoclonal antibody-demonstrated superiority to sorafenib in a Phase III randomized clinical trial. Therefore, this regimen has been approved in several countries as first-line treatment for advanced HCC and is soon expected to be widely used in clinical practice. However, despite the promising results of trials exploring ICIs alone or in combination with other agents, there are still some critical issues to deal with to optimize the prognosis of advanced HCC patients. For instance, the actual proportion of patients who are deemed eligible for ICIs in the real-life ranges from 10% to 20% in the first-line setting, and is even lower in the second-line scenario. Moreover, long-term data regarding the safety of ICIs in the population of patients with cirrhosis and impaired liver function are lacking. Lastly, no biomarkers have been identified to predict response, and thus to help clinicians to individually tailor treatment. This review aimed to summarize the state of the art immunotherapy in HCC and, by analyzing a large, multicenter cohort of Italian patients with HCC, to assess the potential applicability of the combination of atezolizumab/bevacizumab in the real-life setting.

The evolving treatment paradigm of advanced hepatocellular carcinoma: putting all the pieces back together

PURPOSE OF REVIEW

The therapeutic landscape of advanced hepatocellular carcinoma (HCC) has become notably complex in recent years. With this review, we aimed to put the most recent findings in perspective and tried to delineate the rapidly changing treatment algorithm.

RECENT FINDINGS

The combination of atezolizumab and bevacizumab has become the new first-line standard of care treatment for unresectable HCC after the positive results of the phase 3 IMbrave150 study. Nivolumab monotherapy failed to demonstrate advantage versus sorafenib in the CheckMate 459 trial, while two different therapeutic strategies (sintilimab and bevacizumab biosimilar and donafenib) outperformed sorafenib in two phase 2/3 studies conducted in the Chinese population. Several immunotherapy combinations are currently under study in large phase 3 trials after promising results in earlier phase studies. About further lines of treatment, the combination of ipilimumab and nivolumab was approved for sorafenib-pretreated patients after the positive results of the phase 1/2 CheckMate 040 study and apatinib was proven effective in the Chinese population in a phase 2/3 study, while pembrolizumab as monotherapy did not show statistically significant superiority when compared with placebo in the KEYNOTE-240 study.

SUMMARY

Because of the growing complexity of advanced HCC treatment, the implementation of predictive biomarkers of response is eagerly needed.

Hepatocellular Carcinoma: An Overview of the Changing Landscape of Treatment Options

The last three years have seen remarkable progress in comprehending predisposing factors and upgrading our treatment arsenal concerning hepatocellular carcinoma (HCC). Until recently, there were no means to withstand the progression of viral hepatitis-associated liver cirrhosis to HCC. A deeper understanding of the molecular mechanism of the disease, the use of biomarkers, and the follow-up, allowed us to realize that conventional chemotherapy failing to increase survival in patients with advanced HCC tends to be exiled from clinical practice. Multi-kinase inhibitors (TKIs) such as sorafenib, lenvatinib targeting mainly the vascular endothelial growth factor receptors 1–3 VEGFRs 1–3 provided until recently the standard of care for these patients, as first- or second-line treatment. Since May 2020, the atezolizumab plus bevacizumab combination (immunotherapy plus anti-VEGF) has become the new reference standard in first-line HCC treatment. Additionally, anti-programmed cell death protein 1 (anti-PD-1) immunotherapy can be used as a second-line treatment following first-line treatment’s failure. Phase III clinical trials have recently suggested the efficacy of novel anti-angiogenic factors such as cabozantinib and ramucirumab as a second-line treatment option. With considerations about toxicity arising, clinical trials are investigating combinations of the aforementioned targeted therapies with immunotherapy as first-line treatment. This paper aims to perform a systematic review describing the evolving treatment options for HCC over the last decades, ranging from neoadjuvant treatment to systemic therapy of advanced-stage HCC. With the landscape of HCC treatment shifting towards novel agents the forming of a new therapeutic algorithm for HCC seems to be imperative.

Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality and has an increasing incidence worldwide. Locoregional therapies, defined as imaging-guided liver tumour-directed procedures, play a leading part in the management of 50-60% of HCCs. Radiofrequency is the mainstay for local ablation at early stages and transarterial chemoembolization (TACE) remains the standard treatment for intermediate-stage HCC. Other local ablative techniques (microwave ablation, cryoablation and irreversible electroporation) or locoregional therapies (for example, radioembolization and sterotactic body radiation therapy) have been explored, but have not yet modified the standard therapies established decades ago. This understanding is currently changing, and several drugs have been approved for the management of advanced HCC. Molecular therapies dominate the adjuvant trials after curative therapies and combination strategies with TACE for intermediate stages. The rationale for these combinations is sound. Local therapies induce antigen and proinflammatory cytokine release, whereas VEGF inhibitors and tyrosine kinase inhibitors boost immunity and prime tumours for checkpoint inhibition. In this Review, we analyse data from randomized and uncontrolled studies reported with ablative and locoregional techniques and examine the expected effects of combinations with systemic treatments. We also discuss trial design and benchmarks to be used as a reference for future investigations in the dawn of a promising new era for HCC treatment.

Immunotherapy Updates in Advanced Hepatocellular Carcinoma

Simple Summary

Advanced hepatocellular carcinoma (HCC) carries a grim prognosis, which has historically been compounded by a lack of available systemic therapies. Sorafenib monotherapy was the standard of care for front-line treatment of advanced HCC for many years, despite both poor tolerability and lack of durable responses. In the past few years, there have been several clinical trials evaluating the efficacy of immune checkpoint inhibitors for advanced HCC. Use of immune checkpoint inhibitors alone, and in combination with targeted therapies, has led to improved outcomes in both treatment-naïve and subsequent line treatment of advanced HCC. Here we review the role of immunotherapy in the treatment of HCC, describe the mechanistic basis for combination with targeted therapy, and summarize the recent published data as well as ongoing clinical trials for the use of immunotherapy in the treatment of advanced HCC.

Abstract

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide. HCC tumor development and treatment resistance are impacted by changes in the microenvironment of the hepatic immune system. Immunotherapy has the potential to improve response rates by overcoming immune tolerance mechanisms and strengthening anti-tumor activity in the tumor microenvironment. In this review, we characterize the impact of immunotherapy on outcomes of advanced HCC, as well as the active clinical trials evaluating novel combination immunotherapy strategies. In particular, we discuss the efficacy of atezolizumab and bevacizumab as demonstrated in the IMbrave150 study, which created a new standard of care for the front-line treatment of advanced HCC. However, there are multiple ongoing trials that may present additional front-line treatment options depending on their efficacy/toxicity results. Furthermore, the preliminary data on the application of chimeric antigen receptor (CAR-T) cell therapy for treatment of HCC suggests this may be a promising option for the future of advanced HCC treatment.

Anti-PD-1/PD-L1 Based Combination Immunotherapy to Boost Antigen-Specific CD8+ T Cell Response in Hepatocellular Carcinoma

Simple Summary

The cytotoxic T cell response against hepatocellular carcinoma antigens is exhausted and fails in its task of deleting tumoral cells. These cells are featured by the expression of negative immune checkpoints that can be modulated to restore T cell function. The blockade of the PD-1/PD-L1 pathway has shown promising results in rescuing hepatocellular carcinoma-specific CD8 T cells but only a reduced group of cases is sensitive to this treatment and the effect is usually temporary. Therefore, new anti-PD-1 based combinatory strategies are underway to increase the response by adding the effect of blocking neo-angiogenesis and other negative immune checkpoints, boosting positive immune checkpoints, blocking suppressive cytokines, or inducing the expression of tumoral neoantigens. The restoration of T cell responses with these anti-PD-1 based combinatory therapies will change the outcome of advanced hepatocellular carcinoma.

Abstract

Thirty to fifty percent of hepatocellular carcinomas (HCC) display an immune class genetic signature. In this type of tumor, HCC-specific CD8 T cells carry out a key role in HCC control. Those potential reactive HCC-specific CD8 T cells recognize either HCC immunogenic neoantigens or aberrantly expressed host’s antigens, but they become progressively exhausted or deleted. These cells express the negative immunoregulatory checkpoint programmed cell death protein 1 (PD-1) which impairs T cell receptor signaling by blocking the CD28 positive co-stimulatory signal. The pool of CD8 cells sensitive to anti-PD-1/PD-L1 treatment is the PD-1dim memory-like precursor pool that gives rise to the effector subset involved in HCC control. Due to the epigenetic imprints that are transmitted to the next generation, the effect of PD-1 blockade is transient, and repeated treatments lead to tumor resistance. During long-lasting disease, besides the TCR signaling impairment, T cells develop other failures that should be also set-up to increase T cell reactivity. Therefore, several PD-1 blockade-based combinatory therapies are currently under investigation such as adding antiangiogenics, anti-TGFβ1, blockade of other negative immune checkpoints, or increasing HCC antigen presentation. The effect of these combinations on CD8⁺ T cells is discussed in this review.

Progress and Challenges of Predictive Biomarkers for Immune Checkpoint Blockade

Over the past decade, immune checkpoint blockade (ICB) therapy has revolutionized the outlook for oncology with significant and sustained improvement in the overall patient survival. Unlike traditional cancer therapies, which target the cancer cells directly, ICB acts on the immune system to enhance anti-tumoral immunity. However, the response rate is still far from satisfactory and most patients are refractory to such treatment. Unfortunately, the mechanisms underlying such heterogeneous responses between patients to ICB therapy remain unclear. In addition, escalating costs of cancer care and unnecessary immune-related adverse events also are pertinent considerations with applications of ICB. Given these issues, identifying explicit predictive biomarkers for patient selection is an urgent unmet need to increase the efficacy of ICB therapy. The markers can be classified as tumor related and non-tumor-related biomarkers. Although substantial efforts have been put into investigating various biomarkers, none of them has been found to be sufficient for effectively stratifying patients who may benefit from immunotherapy. The present write up is an attempt to review the various emerging clinically relevant biomarkers affecting the efficacy of immune checkpoint inhibitors, as well as the limitations associated with their clinical application.

A Machine Learning Approach Yields a Multiparameter Prognostic Marker in Liver Cancer

A number of staging systems have been developed to predict clinical outcomes in hepatocellular carcinoma (HCC). However, no general consensus has been reached regarding the optimal model. New approaches such as machine learning (ML) strategies are powerful tools for incorporating risk factors from multiple platforms. We retrospectively reviewed the baseline information, including clinicopathologic characteristics, laboratory parameters, and peripheral immune features reflecting T-cell function, from three HCC cohorts. A gradient-boosting survival (GBS) classifier was trained with prognosis-related variables in the training dataset and validated in two independent cohorts. We constructed a 20-feature GBS model classifier incorporating one clinical feature, 14 laboratory parameters, and five T-cell function parameters obtained from peripheral blood mononuclear cells. The GBS model-derived risk scores demonstrated high concordance indexes (C-indexes): 0.844, 0.827, and 0.806 in the training set and validation sets 1 and 2, respectively. The GBS classifier could separate patients into high-, medium- and low-risk subgroups with respect to death in all datasets (P < 0.05 for all comparisons). A higher risk score was positively correlated with a higher clinical stage and the presence of portal vein tumor thrombus (PVTT). Subgroup analyses with respect to Child-Pugh class, Barcelona Clinic Liver Cancer stage, and PVTT status supported the prognostic relevance of the GBS-derived risk algorithm independent of the conventional tumor staging system. In summary, a multiparameter ML algorithm incorporating clinical characteristics, laboratory parameters, and peripheral immune signatures offers a different approach to identify patients with the greatest risk of HCC-related death.

The Role of Immunotherapy in Hepatocellular Carcinoma: A Systematic Review and Pooled Analysis of 2,402 Patients

BACKGROUND

Immune checkpoints inhibitors (ICIs) have emerged as a treatment option for several malignancies. Nivolumab, pembrolizumab, nivolumab plus ipilimumab, and atezolizumab plus bevacizumab have been approved for the management of advanced-stage hepatocellular carcinoma (HCC). We aimed to systematically review the literature and summarize the characteristics and outcomes of patients with HCC treated with ICIs.

METHODS

A systematic literature search of PubMed, the Cochrane Library, and ClinicalTrials.gov was performed according to the PRISMA statement (end of search date: November 7, 2020). Quality of evidence assessment was also performed.

RESULTS

Sixty-three articles including 2,402 patients were analyzed, 2,376 of whom received ICIs for unresectable HCC. Response to ICIs could be evaluated in 2,116 patients; the overall objective response rate (ORR) and disease control rate (DCR) were 22.7% and 60.7%, respectively, and the mean overall survival (OS) was 15.8 months. The ORR, DCR, and OS for nivolumab (n = 846) were 19.7%, 51.1%, and 18.7 months, respectively; for pembrolizumab (n = 435) they were 20.7%, 64.6% and 13.3 months, respectively. The combination of atezolizumab/bevacizumab (n = 460) demonstrated an ORR and DCR of 30% and 77%, respectively. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence); fatal graft rejection was reported in 40.0% (n = 6/15) and mortality in 80.0% (n = 12/15).

CONCLUSION

ICIs are safe and effective against unresectable HCC, but caution is warranted regarding their use in the LT setting because of the high graft rejection rate.

IMPLICATIONS FOR PRACTICE

This systematic review pooled the outcomes from studies reporting on the use of immune checkpoint inhibitors (ICIs) for the management of 2,402 patients with advanced-stage hepatocellular carcinoma (HCC), 2,376 of whom had unresectable HCC. The objective response rate and disease control rate were 22.7% and 60.7%, respectively, and the mean overall survival was 15.8 months. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence). Six of these patients experienced graft rejection (40.0%).

T lymphocytes related biomarkers for predicting immunotherapy efficacy in non-small cell lung cancer

The immune environment is a determinant of whether patients with cancer can benefit from immunotherapy. Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with different types of malignancies and have initiated a transformation in tumor therapy. However, some patients cannot achieve a long-term response and several patients even have no response to ICIs therapy. Thus, potential biomarkers that can effectively predict the efficacy of ICIs are essential for their clinical application and for the selection of patients. The accuracy of well-known biomarkers, such as expression of programmed cell death ligand 1 and tumor mutational burden, remains controversial. One of the critical factors for immune responses in the tumor microenvironment is tumor antigen-specific T cell. The density and distribution of tumor-infiltrating lymphocytes, T cells activation and T lymphocytes phenotypes in peripheral blood and serum cytokines have been observed in different types of solid cancer. Although the association with immunotherapy prognosis is in dispute, the prospect of T cell-related biomarkers is encouraged. The present review discusses whether these factors are associated with clinical outcomes of patients with non-small cell lung cancer. The association between several serum cytokines and ICIs therapy efficacy is also discussed.

Surgical Resection: Old Dog, Any New Tricks?

Patients with hepatocellular carcinoma (HCC) have many treatment options. For patients with surgical indication, consideration of future liver remnant and the surgical complexity of the procedure is essential. A new 3-level complexity classification categorizing 11 liver resection procedures predicts surgical complexity and postoperative morbidity better than reported classifications. Preoperative portal vein embolization can mitigate the risk of hepatic insufficiency. For small HCCs, both liver resection and ablation are effective. New medical treatment options are promising and perioperative use of these drugs may further improve outcomes for patients undergoing liver resection and lead to changes in current treatment guidelines.

Immune Checkpoint Inhibitors in Hepatocellular Cancer: Current Understanding on Mechanisms of Resistance and Biomarkers of Response to Treatment

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy worldwide and a leading cause of death worldwide. Its incidence continues to increase in the US due to hepatitis C infection and nonalcoholic steatohepatitis. Liver transplantation and resection remain the best therapeutic options for cure, but these are limited by the shortage of available organs for transplantation, diagnosis at advanced stage, and underlying chronic liver disease found in most patients with HCC. Immune checkpoint inhibitors (ICIs) have been shown to be an evolving novel treatment option in certain advanced solid tumors and have been recently approved for inoperable, advanced, and metastatic HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. In this review, we discuss the ICIs currently approved for HCC treatment and their various mechanisms of action. We will highlight current understanding of mechanism of resistance and limitations to ICIs. Finally, we will describe emerging biomarkers of response to ICIs and address future direction on overcoming resistance to immune checkpoint therapy.

Neoadjuvant therapy and immunotherapy strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers with high mortality rate worldwide. Due to aggressive and invasive characteristics of HCC, poor prognosis is often displayed at advanced stages while therapeutic options are limited. Liver resection is still an essential curative-intent treatment in HCC management, while locoregional and systematic therapies made promising advances that may improve the proportion and outcomes of patients who are surgical candidates. In this review, we discussed status of currently available neoadjuvant treatments aimed at improving resectability and reducing recurrence rates. More than ever, in order to implement this therapeutic concepts and exploit the full potential of neoadjuvant treatment strategies, it is of utmost importance to use more high-level evidence to guide treatment decision making. Unfortunately, the use of preoperative treatments is not sponsored by tough evidence and consensus guidelines are absent.

Emerging biomarkers in HCC patients: Current status

Hepatocellular carcinoma (HCC) is the liver's most common primary malignancy, with over half a million new cases diagnosed each year and being the fourth leading cause of cancer death, worldwide. The poor prognosis of HCC is largely related to late diagnosis. Historically, serum alpha-fetoprotein and diagnostic imaging have been primary diagnostic modalities. However, the poor prognosis due to late diagnosis of HCC has proven unacceptable and, recently, significant efforts have been devoted to identifying patients with early stage HCC. Molecular biomarkers can provide additional and relevant information about the biological behavior of these tumors. Research in biomarker combinations may provide more accurate and valuable information for the future individualized HCC diagnosis and/or prognosis. Several biomarkers with prognostic significance have been identified, however all of them have been studied retrospectively. Furthermore, of all different molecular signatures that have been published, very few have been externally validated. The aim of this review is to analyze the most relevant emerging biomarkers of HCC.

Challenges of combination therapy with immune checkpoint inhibitors for hepatocellular carcinoma

Immune checkpoint inhibitor (ICI) therapy targeting anti-programmed cell death-1 (anti-PD-1) or its ligand (anti-PD-L1) is the backbone of numerous combination regimens aimed at improving the objective response and survival of patients with hepatocellular carcinoma (HCC). Clinical trials of immuno-oncology regimens in other cancer types have shed light on issues of study design, including how to choose candidate regimens based on early-phase trial results, statistical considerations in trials with multiple primary endpoints, and the importance of predictive biomarkers. In this review, the updated data from early-phase trials of combination immunotherapy for HCC are summarised. Since the most extensively tested combination regimens for advanced HCC comprise anti-PD-1/anti-PD-L1 agents plus antiangiogenic agents, the relative benefit and antitumor mechanism of antiangiogenic multikinase inhibitors versus specific VEGF/VEGFR inhibitors are discussed. Other critical issues in the development of combination immunotherapy, including optimal management of immune-related adverse events and the value of ICI therapy in combination with locoregional treatment for HCC, are also explored.

Advances in resection and transplantation for hepatocellular carcinoma

It would be impossible to summarise all of the significant developments in the surgical management of hepatocellular carcinoma (HCC), even just over the past year, in a manuscript of this scope. Thus, we have selected topics for discussion that are the subject of current controversy and have attempted to present balanced points of view. Hepatic resection and transplantation are both mature modalities, and for the most part technical advances and improvements in candidate selection are incremental. The ability to readily cure hepatitis C stands out as the most impactful development in the field over recent years, especially in Western countries where hepatitis C has long been the chief aetiology underlying HCC and a predictor of poor outcomes after surgery, but its full implications remain to be clarified. The rising incidence of non-alcoholic steatohepatitis-related HCC and what it means with regard to surgical HCC management is an area of great current interest. With advancing technology, non-surgical locoregional treatments are gaining increasing application as potentially curative therapies. In addition, the advances in molecular and genomic assessment of HCC hold promise for personalising treatment and prognostication. The possible role of immunotherapy as an adjuvant to resection is being aggressively investigated. While liver surgery maintains an important role, the care of patients with HCC is more and more a team effort and needs to take place in the context of a well-integrated interdisciplinary programme to achieve the best outcomes for patients.