Percutaneous Ablation-Induced Immunomodulation in Hepatocellular Carcinoma. Int J Mol Sci. 2020;21. [PMID: 32575734 PMCID: PMC7352237 DOI: 10.3390/ijms21124398]

Short-term efficacy of microwave ablation in the treatment of liver cancer and its effect on immune function

BACKGROUND

Hepatectomy is the first choice for treating liver cancer. However, inflammatory factors, released in response to pain stimulation, may suppress perioperative immune function and affect the prognosis of patients undergoing hepatectomies.

AIM

To determine the short-term efficacy of microwave ablation in the treatment of liver cancer and its effect on immune function.

METHODS

Clinical data from patients with liver cancer admitted to Suzhou Ninth People’s Hospital from January 2020 to December 2023 were retrospectively analyzed. Thirty-five patients underwent laparoscopic hepatectomy for liver cancer (liver cancer resection group) and 35 patients underwent medical image-guided microwave ablation (liver cancer ablation group). The short-term efficacy, complications, liver function, and immune function indices before and after treatment were compared between the two groups.

RESULTS

One month after treatment, 19 patients experienced complete remission (CR), 8 patients experienced partial remission (PR), 6 patients experienced stable disease (SD), and 2 patients experienced disease progression (PD) in the liver cancer resection group. In the liver cancer ablation group, 21 patients experienced CR, 9 patients experienced PR, 3 patients experienced SD, and 2 patients experienced PD. No significant differences in efficacy and complications were detected between the liver cancer ablation and liver cancer resection groups (P > 0.05). After treatment, total bilirubin (41.24 ± 7.35 vs 49.18 ± 8.64 μmol/L, P < 0.001), alanine aminotransferase (30.85 ± 6.23 vs 42.32 ± 7.56 U/L, P < 0.001), CD4⁺ (43.95 ± 5.72 vs 35.27 ± 5.56, P < 0.001), CD8⁺ (20.38 ± 3.91 vs 22.75 ± 4.62, P < 0.001), and CD4⁺/CD8⁺ (2.16 ± 0.39 vs 1.55 ± 0.32, P < 0.001) were significantly different between the liver cancer ablation and liver cancer resection groups.

CONCLUSION

The short-term efficacy and safety of microwave ablation and laparoscopic surgery for the treatment of liver cancer are similar, but liver function recovers quickly after microwave ablation, and microwave ablation may enhance immune function.

Macrophage hitchhiking for systematic suppression in postablative multifocal HCC

BACKGROUND AND AIMS

HCC, particularly the multifocal HCC, features aggressive invasion and dismal prognosis. Locoregional treatments were often refractory to eliminate tumor tissue, resulting in residual tumor cells persisting and subsequent progression. Owing to problematic delivery to the tumor tissue, systemic therapies, such as lenvatinib (LEN) therapy, show limited clinical benefit in preventing residual tumor progression. Therefore, more advanced strategies for postablative multifocal HCC are urgently needed.

APPROACH AND RESULTS

Motivated by the chemotaxis in tumor penetration of macrophages, we report a strategy named microinvasive ablation-guided macrophage hitchhiking for the targeted therapy toward HCC. In this study, the strategy leverages the natural inflammatory gradient induced by ablation to guide LEN-loaded macrophages toward tumor targeting, which increased by ~10-fold the delivery efficiency of LEN in postablative HCC in vivo. Microinvasive ablation-guided macrophage hitchhiking has demonstrated significant antitumor activity in various HCC models, including the hydrodynamic tail vein injection multifocal HCC mouse model and the orthotopic xenograft HCC rabbit model, systematically inhibiting residual tumor progression after ablation and prolonging the median survival of tumor-bearing mice. The potential antitumor mechanism was explored using techniques such as flow cytometry, ELISA, and immunohistochemistry. We found that the strategy significantly suppressed tumor cell proliferation and neovascularization, and such enhanced delivery of LEN stimulated systemic immune responses and induced durable immune memory.

CONCLUSIONS

The macrophage hitchhiking strategy demonstrates exceptional therapeutic efficacy and biosafety across various species, offering promising prospects for clinical translation in controlling residual tumor progression and improving outcomes following HCC ablation.

Peripheral T-cell subsets in radiofrequency ablation for tumors from different origins

BACKGROUNDS

Radiofrequency ablation (RFA) is known to destroy tumoral tissue and activate immune cells. This study aimed to investigate the impact of RFA on peripheral T-cell responses and its relationship with tumor origin and hepatitis status.

METHODS

A retrospective analysis was conducted on 62 patients with various types of tumors, including hepatocellular carcinoma, colorectal cancer, lung cancer, breast cancer, and others, who underwent RFA treatment between June 2017 and December 2018. Blood samples were collected before and one day after RFA treatment. The peripheral T-cell subsets were measured by flow cytometry, and their changes were analyzed.

RESULTS

The study found a decrease in the CD4+CD8-and CD4-CD8+ T-cell subsets after RFA, but no significant changes were observed in the populations of CD4+CD8+ and the CD4+CD8-/CD4-CD8+ ratio. Furthermore, no significant differences were observed in peripheral T-cell subsets concerning tumor type or hepatitis status.

CONCLUSIONS

The study suggests that RFA treatment may have a short-term impact on peripheral T-cell responses, characterized by a decrease in certain T-cell subsets. However, these changes do not seem to be related to the tumor type or hepatitis status of the patients.

PD1 and TIM3 Expression is Associated with Very Early Hepatocellular Carcinoma Recurrence After Percutaneous Thermal Ablation

Purpose

Percutaneous thermal ablation (PTA) is a cornerstone in the management of early-stage hepatocellular carcinoma (HCC). However, intrahepatic distant recurrence (IDR) occurs in the majority of patients after PTA. The aim of this study was to evaluate the immune signature associated with very early IDR.

Patients and Methods

Thirty-one patients (26 men, 5 women; mean age:72.4 ± 8.6; age range:57-86 years) who underwent PTA for HCC were included in this study. After PTA for HCC, patients were followed and later divided into two groups: a "very early recurrence" group in case of IDR within 12 months after PTA, and a "prolonged recurrence-free" group in case of no recurrence before 12 months of follow-up. Freshly harvested intratumoral and nontumoral liver tissues and peripheral blood were obtained before PTA and explored by multiparametric flow cytometry.

Results

The frequency of PD1+CD4+ T cells was higher in the early recurrence group than in the prolonged recurrence-free group in the peripheral blood (24.3%, IQR: 22.3-36.5 vs 14.0%, IQR: 11.5-16.4, p<0.0001), in the nontumoral liver (37.9%, IQR: 36.0-50.0 vs 22.5%, IQR: 18.0-29.9, p=0.0004), and in the tumor (37.6%, IQR: 32.3-39.3 vs 24.0%, IQR: 20.0-30.3, p=0.0137). Similarly, the frequency of TIM+CD8+ T cells was higher in the very early recurrence group in the peripheral blood (p=0.0021), non-tumoral liver (p=0.0012), and tumor (p=0.0239).

Conclusion

The expression of immune checkpoint molecules, such as PD1 and TIM3 on T cells identified HCC patients at risk of very early IDR after PTA who would likely benefit from adjuvant immunotherapy. Thus, our study contributes to a better understanding of the potential association of PTA with adjuvant immunotherapies.

Autophagy-amplifying nanoparticles evoke immunogenic cell death combined with anti-PD-1/PD-L1 for residual tumors immunotherapy after RFA

Incomplete radiofrequency ablation (IRFA) triggers mild protective autophagy in residual tumor cells and results in an immunosuppressive microenvironment. This accelerates the recurrence of residual tumors and causes resistance to anti-PD-1/PDL1 therapy, which bringing a great clinical challenge in residual tumors immunotherapy. Mild autophagy activation can promote cancer cell survival while further amplification of autophagy contributes to immunogenic cell death (ICD). To this regard, we constructed active targeting zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) loaded with STF62247 or both STF62247 and BMS202, namely STF62247@ZIF-8/PEG-FA (SZP) or STF62247-BMS202@ZIF-8/PEG-FA (SBZP) NPs. We found that SZP NPs inhibited proliferation and stimulated apoptosis of residual tumor cells exposed to sublethal heat stress in an autophagy-dependent manner. Further results discovered that SZP NPs could amplify autophagy in residual tumor cells and evoke their ICD, which dramatically boosted the maturation of dendritic cells (DCs). Through vaccination experiments, we found for the first time that vaccination with heat + SZP treatment could efficiently suppress the growth of new tumors and establish long-term immunological memory. Furthermore, SBZP NPs could remarkably promote the ICD of residual tumor cells, obviously activate the anti-tumor immune microenvironment, and significantly inhibit the growth of residual tumors. Thus, amplified autophagy coupled with anti-PD-1/PDL1 therapy is potentially a novel strategy for treating residual tumors after IRFA.

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.

Immunotherapeutic approaches in Hepatocellular carcinoma: Building blocks of hope in near future

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic cancer and is among the major causes of mortality due to cancer. Due to the lack of efficient conventional therapeutic options for this cancer, particularly in advanced cases, novel treatments including immunotherapy have been considered. However, despite the encouraging clinical outcomes after implementing these innovative approaches, such as oncolytic viruses (OVs), adoptive cell therapies (ACT), immune checkpoint blockades (ICBs), and cancer vaccines, several factors have restricted their therapeutic effect. The main concern is the existence of an immunosuppressive tumor microenvironment (TME). Combination of different ICBs or ICBs plus tyrosine kinase inhibitors have shown promising results in overcoming these limiting factors to some extent. Combination of programmed cell death ligand-1 (PD-L1) antibody Atezolizumab and vascular endothelial growth factor (VEGF) antibody Bevacizumab has become the standard of care in the first-line therapy for untestable HCC, approved by regulatory agencies. This paper highlighted a wide overview of the direct and indirect immunotherapeutic strategies proposed for the treatment of HCC patients and the common challenges that have hindered their further clinical applications.

Application of ablative therapy for intrahepatic recurrent hepatocellular carcinoma following hepatectomy

The post-hepatectomy recurrence rate of hepatocellular carcinoma (HCC) is persistently high, affecting the prognosis of patients. An effective therapeutic option is crucial for achieving long-term survival in patients with postoperative recurrences. Local ablative therapy has been established as a treatment option for resectable and unresectable HCCs, and it is also a feasible approach for recurrent HCC (RHCC) due to less trauma, shorter operation times, fewer complications, and faster recovery. This review focused on ablation techniques, description of potential candidates, and therapeutic and prognostic implications of ablation for guiding its application in treating intrahepatic RHCC.

Comparison of NK cell subsets, receptors and functions induced by radiofrequency ablation and microwave ablation in HBV-associated primary hepatocellular carcinoma

Background

Topical therapy has been shown to induce an immune response in patients with hepatocellular carcinoma (HCC). In this study, a prospective parallel group control experiment was conducted to compare the differences between radiofrequency ablation and microwave ablation in inducing the immune regulation of NK cells.

Methods

Sixty patients with clinically and pathologically confirmed hepatitis B-associated hepatocellular carcinoma (HCC) were selected for thermal ablation. Patients were randomly assigned into the MWA group (n = 30) and the RFA group (n = 30). Patient's peripheral blood was isolated on days D0, D7, and month M1. NK cell subsets, receptors, and killing function were detected by flow cytometry and LDH. Student t test and rank sum test were used to compare the statistical differences between the RFA (radio frequency) and MWA (microwave) groups. The Kaplan-Meier curve and log-rank test were used to calculate the difference between the two survival curves.

Results

Comparison of the frequency of CD3-CD56+ and CD3-CD56+CD16+ in NK cells between the RFA and WMA groups showed that there was no difference in the D0, D7, M1, D7-D0, M1-D0, and M1-D7 groups. The changes of the inhibitory NK cell receptor CD159A were significantly different at D7 (P<0.05). CD107a were compared between the RFA and WMA groups, indicating that CD107a changes induced by NK cells were significantly different at D7-D0 (P<0.05). Comparison of NK cell lysis activity of target K562 cells between the RFA and WMA groups showed that there was no difference at D0, D7, D7-D0. There was no difference in recurrence-free survival (RFS) between the RFA and WMA groups (P=0.11).

Conclusions

The difference between MWA and RFA-induced NK cell changes was mainly manifested in the inhibitory receptors CD159a and CD107a 1 week after surgery, with microwave-induced changes being more severe. Comparison of the NK cell lysis activity of the target K562 cells between the RFA and WMA groups showed that there was no difference in D0, D7, D7- D0. Survival analysis showed that these differences did not affect the recurrence-free survival (RFS) in the two groups.

Microwave ablation induces abscopal effect via enhanced systemic antitumor immunity in colorectal cancer

Background

Thermal ablation is the primary procedure for the local treatment of lung metastases. It is known that radiotherapy and cryoablation can stimulate an abscopal effect, while the occurrence of abscopal effect induced by microwave ablation is less; the cellular and molecular mechanisms involved in the abscopal effect after microwave ablation should be further elucidated.

Methods

CT26 tumor-bearing Balb/c mice were treated with microwave ablation with several combinations of ablation power and time duration. The growth of primary or abscopal tumors and the survival of mice were both monitored; moreover, immune profiles in abscopal tumors, spleens, and lymph nodes were examined by flow cytometry.

Results

Microwave ablation suppressed tumor growth in both primary and abscopal tumors. Both local and systemic T-cell responses were induced by microwave ablation. Furthermore, the mice exhibiting significant abscopal effect after microwave ablation markedly elevated Th1 cell proportion both in the abscopal tumors and spleens.

Conclusions

Microwave ablation at 3 w-3 min not only suppressed tumor growth in the primary tumors but also stimulated an abscopal effect in the CT26-bearing mice via the improvement of systemic and intratumoral antitumor immunity.

Immunogenic change after percutaneous microwave ablation in pulmonary malignancies: Variation in immune cell subsets and cytokines in peripheral blood

Introduction

To investigate immunogenic changes after percutaneous microwave ablation (MWA) in pulmonary malignancies.

Methods

Twenty-two consecutive patients with pulmonary malignancies who underwent percutaneous lung tumor MWA were prospectively enrolled in this study. Peripheral blood samples were collected on the day before (D0) and one month (M1) after MWA. Changes in immune cell subsets (CD3+, CD4+, and CD8+ T cells, and B, natural killer, regulatory T (Treg), and CD3-CD20+ cells) and cytokines (interleukin [IL]-2, 4, 6, 10, 17A, tumor necrosis factor [TNF]-α, and interferon-γ) were noted and compared. Progression-free survival (PFS) and potentially related factors were analyzed.

Results

The proportion of CD8+ T cells increased from 22.95 ± 7.38% (D0) to 25.95 ± 9.16% (M1) (p = 0.031). The proportion of Treg cells decreased from 10.82 ± 4.52% (D0) to 8.77 ± 2.05% (M1) (p = 0.049). The IL-2 concentration was also decreased from 1.58 ± 0.46 pg/mL (D0) to 1.26 ± 0.60 pg/mL (M1) (p = 0.028). The reduction in Treg cells predicted PFS independently of clinical prognostic features in multivariate analysis (hazard ratio = 4.97, 95% confidence interval: 1.32-18.66, p = 0.018). A reduction in the proportion of Treg cells was observed in 15 patients (68.2%) and the average of the reduction was 2.05 ± 4.60%. Those patients with a reduction in the proportion of Treg cells that was more than average showed a significantly longer median PFS time than those with a reduction that was less than average (16 months vs. 8.5 months, p = 0.025).

Discussion

Percutaneous MWA of pulmonary malignancies leads to immunogenic changes. The reduction in the proportion of Treg cells was independently associated with PFS.

Rational Nanomedicine Design Enhances Clinically Physical Treatment-Inspired or Combined Immunotherapy

Independent of tumor type and non-invasive or minimally-invasive feature, current physical treatments including ultrasound therapy, microwave ablation (MWA), and radiofrequency ablation (RFA) are widely used as the local treatment methods in clinics for directly killing tumors and activating systematic immune responses. However, the activated immune responses are inadequate and incompetent for tumor recession, and the incomplete thermal ablation even aggravates the immunosuppressive tumor microenvironment (ITM), resulting in the intractable tumor recurrence and metastasis. Intriguingly, nanomedicine provides a powerful platform as they can elevate energy utilization efficiency and augment oncolytic effects for mitigating ITM and potentiating the systematic immune responses. Especially after combining with clinical immunotherapy, the anti-tumor killing effect by activating or enhancing the human anti-tumor immune system is reached, enabling the effective prevention against tumor recurrence and metastasis. This review systematically introduces the cutting-edge progress and direction of nanobiotechnologies and their corresponding nanomaterials. Moreover, the enhanced physical treatment efficiency against tumor progression, relapse, and metastasis via activating or potentiating the autologous immunity or combining with exogenous immunotherapeutic agents is exemplified, and their rationales are analyzed. This review offers general guidance or directions to enhance clinical physical treatment from the perspectives of immunity activation or magnification.

Immune modulation by molecularly targeted photothermal ablation in a mouse model of advanced hepatocellular carcinoma and cirrhosis

Immunotherapy is a promising new treatment approach for hepatocellular carcinoma (HCC), but there are numerous barriers to immunotherapy in HCC, including an immunosuppressive microenvironment and the "immunotolerance" of the liver. Hyperthermia treatment modalities are standard of care for early stage HCC, and hyperthermia is known to have immunomodulatory effects. We have developed a molecularly targeted photothermal ablation (MTPA) technology that provides thermally tunable, tumor-specific heat generation. The purpose of this study was to evaluate the morphologic and immunologic effects of MTPA in an immunotherapy-resistant syngeneic mouse model of HCC in a background of toxin-induced cirrhosis. We found that the anatomic, cellular, and molecular features of this model recapitulate the characteristics of advanced human HCC. MTPA as a monotherapy and in combination with immune checkpoint therapy significantly increased intratumoral CD3+ and activated CD8+ T cells while decreasing regulatory T cells relative to control or immune checkpoint therapy alone based on immunohistochemistry, flow cytometry, and single cell RNA sequencing data. Furthermore, we identified evidence of MTPA's influence on systemic tumor immunity, with suppression of remote tumor growth following treatment of orthotopic tumors. The results of this study suggest that tumor-specific hyperthermia may help overcome resistance mechanisms to immunotherapy in advanced HCC.

Hyperthermia combined with immune checkpoint inhibitor therapy in the treatment of primary and metastatic tumors

According to the difference in temperature, thermotherapy can be divided into thermal ablation and mild hyperthermia. The main advantage of thermal ablation is that it can efficiently target tumors in situ, while mild hyperthermia has a good inhibitory effect on distant metastasis. There are some similarities and differences between the two therapies with respect to inducing anti-tumor immune responses, but neither of them results in sustained systemic immunity. Malignant tumors (such as breast cancer, pancreatic cancer, nasopharyngeal carcinoma, and brain cancer) are recurrent, highly metastatic, and highly invasive even after treatment, hence a single therapy rarely resolves the clinical issues. A more effective and comprehensive treatment strategy using a combination of hyperthermia and immune checkpoint inhibitor (ICI) therapies has gained attention. This paper summarizes the relevant preclinical and clinical studies on hyperthermia combined with ICI therapies and compares the efficacy of two types of hyperthermia combined with ICIs, in order to provide a better treatment for the recurrence and metastasis of clinically malignant tumors.

Techniques for Profiling the Cellular Immune Response and Their Implications for Interventional Oncology

In recent years there has been increased interest in using the immune contexture of the primary tumors to predict the patient's prognosis. The tumor microenvironment of patients with cancers consists of different types of lymphocytes, tumor-infiltrating leukocytes, dendritic cells, and others. Different technologies can be used for the evaluation of the tumor microenvironment, all of which require a tissue or cell sample. Image-guided tissue sampling is a cornerstone in the diagnosis, stratification, and longitudinal evaluation of therapeutic efficacy for cancer patients receiving immunotherapies. Therefore, interventional radiologists (IRs) play an essential role in the evaluation of patients treated with systemically administered immunotherapies. This review provides a detailed description of different technologies used for immune assessment and analysis of the data collected from the use of these technologies. The detailed approach provided herein is intended to provide the reader with the knowledge necessary to not only interpret studies containing such data but also design and apply these tools for clinical practice and future research studies.

Ultrasound-guided microwave ablation as a palliative treatment for mycosis fungoides eyelid involvement: A case report

BACKGROUND

Mycosis fungoides (MF) is a form of lymphoma derived from heterogeneous T cells, and eyelid involvement is extremely rare. The common methods to treat eyelid involvement are radiotherapy and chemotherapy, but their efficacies are limited. Herein, we report a case of advanced-stage MF eyelid involvement, propose ultrasound (US)-guided microwave ablation (MWA) therapy and present a literature review.

CASE SUMMARY

A male patient was admitted to our hospital in June 2018 and diagnosed with MF via radiological and histopathological examinations. The patient’s condition was not well controlled by various conventional chemotherapies. US-guided MWA was performed to relieve the patient’s symptoms and improve his quality of life, showing satisfactory efficacy.

CONCLUSION

Eyelid involvement is one of the most troublesome clinical problems for advanced-stage MF patients. This is the first report on the use of US-guided MWA as a palliative therapy for MF eyelid involvement; the treatment successfully relieved the patient’s clinical symptoms and reduced his anxiety behaviours. Our study sheds new light on methods for improving the clinical management of eyelid involvement in MF.

Evaluation of short- and medium-term efficacy and complications of ultrasound-guided ablation for small liver cancer

BACKGROUND

To ensure clinical efficacy and prolong patient survival, treatments such as surgery and microwave ablation (MWA) are used for early liver cancer. MWA is preferred because it effectively preserves the normal liver tissue and causes transient coagulation necrosis of local liver tumor cells. However, due to technical limitations, the cancerous liver tissue cannot be completely ablated; therefore, the probability of local tumor recurrence is high.

AIM

To investigate the clinical efficacy and safety of ultrasound-guided percutaneous MWA in the treatment of small liver cancer.

METHODS

A total of 118 patients treated for small liver cancer in The Central Hospital of Yongzhou from January 2018 to April 2019 were selected. Sixty-six patients received ultrasound-guided percutaneous MWA (MWA group) and 52 received laparoscopic surgery (laparoscope group). The operation time, blood loss, hospital stay, and medical expenses of both groups were statistically analyzed. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), albumin (ALB), alpha fetal protein (AFP), carcinoembryonic antigen (CEA), and peripheral blood regulatory T lymphocytes (Treg) levels were evaluated pre- and post-operatively. The cross-sectional area of tumors measured before and after ablation was analyzed statistically; the therapeutic effect was compared between both groups in terms of surgical complications, 2-year progression-free survival rate, and overall survival rate.

RESULTS

The operation time, blood loss, hospital stay, and medical expenses in the MWA group were lower than those of the laparoscope group, and the differences were significant (P < 0.05); these parameters, and ALT, AST, TBIL, and ALB levels were compared preoperatively between both groups, and there was no significance (P > 0.05). The operation time, blood loss, hospital stay, and medical expenses for 2 d and 1 wk after surgery, the ALT and AST of the MWA group were lower than those of the laparoscope group, and the difference was significant (P < 0.05). The operation time, blood loss, hospital stay, and medical expenses, and serum AFP, CEA, and Treg levels were measured preoperatively and 4 and 8 wk postoperatively, and there were no significant differences between the two groups (P > 0.05). Compared with preoperative levels, serum AFP, CEA, and Treg levels in both groups were decreased (P < 0.05). The lesion in the MWA group had a maximum area of 4.86 ± 0.90 cm2, 1.24 ± 0.57 cm2, and 0.31 ± 0.11 cm2 preoperatively, 1 and 3 mo postoperatively, respectively. Fifty-eight of them achieved complete response and eight achieved a partial response. After 2 years of follow-up, the progression-free and overall survival rates in the MWA group were 37.88% and 66.67%, respectively, compared with 44.23% and 76.92% in the laparoscope group, with no significant difference (P > 0.05).

CONCLUSION

The effects of ultrasound-guided percutaneous MWA in the treatment of small liver cancer are similar to those of laparoscopic surgery. However, ablation causes less trauma and liver dysfunction.

Immunomodulation for hepatocellular carcinoma therapy: current challenges

PURPOSE OF REVIEW

The emergence of novel immunotherapies, such as immune-checkpoint inhibitors has changed the landscape of systemic cancer treatment. In hepatocellular carcinoma (HCC) patients, despite initial enthusiasm, the proportion of responders to immune-checkpoint inhibitors remains low. We provide a brief update of this rapidly evolving field, with specific focus on the development in the field of predictive factors and the immunomodulation induced by locoregional therapies.

RECENT FINDINGS

Even if the immune contexture of HCC before the treatment remains the most promising predictive marker for response to immunotherapies, recent findings show that the cause of HCC may have also a key role. Specific inflammatory mechanisms induced by NASH may result in limited efficacy of immunotherapy compared with viral HCC. Other recent findings showed that percutaneous ablations are responsible for intratumoral immune changes and systemic immune system activation that may help to prevent recurrence when combined with immunotherapies. In case of multifocal HCC, transarterial therapies (TACE and SIRT) may help to turn a cold tumor type to a hot tumor type and could be associated with immune-checkpoint inhibitors to improve outcomes.

SUMMARY

The future HCC management will focus on patient stratification for specific immunotherapies depending on the signature and cause of HCC and the best combined approaches in which locoregional therapies may play a pivotal role.

Augmented EPR effect post IRFA to enhance the therapeutic efficacy of arsenic loaded ZIF-8 nanoparticles on residual HCC progression

BACKGROUND

Insufficient radiofrequency ablation (IRFA) can promote the local recurrence and distal metastasis of residual hepatocellular carcinoma (HCC), which makes clinical treatment extremely challenging. In this study, the malignant transition of residual tumors after IRFA was explored. Then, arsenic-loaded zeolitic imidazolate framework-8 nanoparticles (As@ZIF-8 NPs) were constructed, and their therapeutic effect on residual tumors was studied.

RESULTS

Our data showed that IRFA can dramatically promote the proliferation, induce the metastasis, activate the epithelial-mesenchymal transition (EMT) and accelerate the angiogenesis of residual tumors. Interestingly, we found, for the first time, that extensive angiogenesis after IRFA can augment the enhanced permeability and retention (EPR) effect and enhance the enrichment of ZIF-8 nanocarriers in residual tumors. Encouraged by this unique finding, we successfully prepared As@ZIF-8 NPs with good biocompatibility and confirmed that they were more effective than free arsenic trioxide (ATO) in sublethal heat-induced cell proliferation suppression, apoptosis induction, cell migration and invasion inhibition, and EMT reversal in vitro. Furthermore, compared with free ATO, As@ZIF-8 NPs exhibited remarkably increased therapeutic effects by repressing residual tumor growth and metastasis in vivo.

CONCLUSIONS

This work provides a new paradigm for the treatment of residual HCC after IRFA.

Application of Immunotherapy in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the most common malignancies globally. It not only has a hidden onset but also progresses rapidly. Most HCC patients are already in the advanced stage of cancer when they are diagnosed, and have even lost the opportunity for surgical treatment. As an inflammation-related tumor, the immunosuppressive microenvironment of HCC can promote immune tolerance through a variety of mechanisms. Immunotherapy can activate tumor-specific immune responses, which brings a new hope for the treatment of HCC. At the present time, main immunotherapy strategies of HCC include immune checkpoint inhibitors, tumor vaccines, adoptive cell therapy, and so on. This article reviews the application and research progress of immune checkpoint inhibitors, tumor vaccines, and adoptive cell therapy in the treatment of HCC.

Influence of the heat irrigating effect of radiofrequency ablation on regional liver tissue in Bama miniature pigs

BACKGROUND

The results of the heat irrigating effect of radiofrequency ablation (RFA) are uncertain, and the accurate impact of the heat irrigating effect on regional liver tissue is unknown due to a lack of control experiments.

AIM

The aim of this study was to determine the influence of the heat irrigating effect of RFA on regional liver tissue in Bama miniature pigs.

METHODS

Eight Bama miniature pigs were randomly divided into the observation group (group A) and the control group (group B), with 4 pigs/group. An RFA electrode needle was implanted near the hepatic segment vasculature (3-5 mm from the hepatic segment portal vein) under ultrasound guidance in group A. Similarly, an RFA electrode needle was implanted far from the hepatic segment vasculature (8-10 mm from the hepatic segment portal vein) in group B. The left internal lobe and right medial lobe were chosen as RFA sites in each pig. RFA was performed at the left internal lobe on day one in each pig, and at the right medial lobe 7 d later. Each RFA lasted 12 min. The general status of the pigs and serious complications were observed during the perioperative period. The pigs were sacrificed and the livers were removed immediately after RFA on the eighth day. The samples were roughly observed. Hematoxylin-eosin and Ki67 staining, as well as TUNEL detection, were performed on the tissue sections.

RESULTS

All 8 animals successfully underwent ultrasound-guided RFA. No serious complications, such as massive hemorrhage, biliary fistula, severe pleural effusion, pneumothorax, peripheral organ failure, or renal failure occurred in any of the animals during the perioperative period. The RFA coagulative necrosis lesion was spherical and the surrounding liver tissue showed an inflammatory response. The difference in the Suzuki score of the liver tissue surrounding the ablated portal vein, and its distal area between groups A and B, was statistically significant (P < 0.05). More apoptotic cells were seen in liver tissue surrounding the ablated portal vein and its distal area in group A, while fewer apoptotic cells in the same area were seen in group B. The difference in the apoptotic index of the above area between group A and group B was statistically significant (P < 0.05). Cells staining positive for Ki67 were observed in liver tissue at the left internal lobe around the ablated portal vein and its distal area in group A. No Ki67 staining positive cells were observed in other tissue sections. The difference in the Ki67 staining positive index in the above area was statistically significant (P < 0.05) between group A and group B.

CONCLUSION

Changes as a result of thermal damage occur in liver tissue around the ablated portal vein and its distal area due to the heat irrigating effect when the RFA electrode tip is close to (< 5 mm) the portal vein.

Bilious pleuritis due to hepatic microwave ablation: Two illustrative cases and literature review

Ultrasound guided percutaneous thermal ablation has been well acknowledged in treating hepatic malignancy. Although thermal ablation is safe for the treatment, it may induce some lethal complications such as diaphragmatic injury, bile-stained pleural fistula, and bilious pleuritis.We presented 2 cancer patients in hepatic diaphragmatic dome showed diaphragmatic injury, bile-stained pleural fistula, and bilious pleuritis after microwave ablation (MVA). The symptoms were attenuated after chest drainage and anti-infection therapy. In the literature review, 17 articles published in the recent 10 years on diaphragmatic injury after MVA for treating hepatic cancer were available. Twenty-three cases were obtained, among which 2 showed bilious pleuritis after radiofrequency treatment. Most of the lesions were adjacent to the diaphragma. Among the articles reporting the localization of lesions, most of the cases showed lesions in S8, 2 in S7, 3 in S4, and 3 in S5, respectively. Surgical recovery was required for the patients with massive diaphragmatic injury. Only 2 cases underwent thorascopic surgery. After chest drainage and anti-infection, their symptoms were attenuated to some extent.Radiofrequency or MVA may induce pleural effusion, and special attention should be paid to the diaphragmatic injury induced by thermal ablation.

Ablation Reboots the Response in Advanced Hepatocellular Carcinoma With Stable or Atypical Response During PD-1 Therapy: A Proof-of-Concept Study

Background: The anti-programmed cell death protein-1 (PD-1) inhibitor is one of the second-line therapies for advanced hepatocellular carcinoma (HCC) after sorafenib failure. The goal of this study is to evaluate the feasibility and safety of ablation on the tumor in patients with advanced HCC who had stable disease or atypical response during single anti-PD-1 therapy after sorafenib failure. Atypical response defined as mixed responses in different lesions of the same individual (e.g., active or stable lesions mixed with progressive lesions).

Patients and Methods: This proof-of-concept clinical trial enrolled 50 patients treated with an anti-PD-1 inhibitor of nivolumab or pembrolizumab monotherapy between July 2015 and Nov 2017. Thirty-three cases with stable disease or atypical response to anti-PD-1 inhibitor received subtotal thermal ablation. The safety and the response of ablation during anti-PD-1 therapy were evaluated. The survival was estimated by the Kaplan-Meier curve.

Results: Of all 50 patients treated with anti-PD-1 therapy, the rate of response, stable disease, atypical and typical progression were 10% (n = 5), 42% (n = 21) 32% (n = 16), and 12% (n = 6), respectively. Additional ablation improved efficacy with tolerable toxicity, and the response rate was increased from 10 to 24% (12/50). The median time to progression, progression-free survival, and overall survival was 6.1 months (95%CI, 2.6–11.2), 5 months (95%CI, 2.9–7.1), and 16.9 months (95%CI, 7.7–26.1), respectively.

Conclusions: This proof-of-concept trial suggested that additional ablation may increase the objective response rate with tolerated toxicity and achieved a relatively better median survival, in advanced HCC patients who had stable or atypical progressive diseases during anti-PD-1 therapy, which may provide a potentially promising strategy to treat advanced HCC.

Trial registration number:ClinicalTrials.gov identifier: NCT03939975.