Cryoablation inhibition of distant untreated tumors (abscopal effect) is immune mediated

Immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major global healthcare challenge, with >1 million patients predicted to be affected annually by 2025. In contrast to other cancers, both incidence and mortality rates continue to rise, and HCC is now the third leading cause of cancer-related death worldwide. Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for advanced HCC, with trials demonstrating a superior overall survival benefit compared to sorafenib in the first-line setting. Combination therapy with either atezolizumab (anti-PD-L1) and bevacizumab (anti-VEGF) or durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4) is now recognised as standard of care for advanced HCC. More recently, two phase III studies of ICI-based combination therapy in the early and intermediate disease settings have successfully met their primary end points of improved recurrence- and progression-free survival, respectively. Despite these advances, and in contrast to other tumour types, there remain no validated predictive biomarkers of response to ICIs in HCC. Ongoing research efforts are focused on further characterising the tumour microenvironment in order to select patients most likely to benefit from ICI and identify novel therapeutic targets. Herein, we review the current understanding of the immune landscape in which HCC develops and the evidence for ICI-based therapeutic strategies in HCC. Additionally, we describe the state of biomarker development and novel immunotherapy approaches in HCC which have progressed beyond the pre-clinical stage and into early-phase trials.

Combined cryoablation and PD-1 inhibitor synergistically enhance antitumor immune responses in Lewis lung adenocarcinoma mice via the PI3K/AKT/mTOR pathway

Cryoablation is a therapeutic modality for lung adenocarcinoma that destroys target tumors using lethal levels of cold, resulting in the release of large amounts of specific antigens that activate immune responses. However, tumor immune checkpoint escape mechanisms prevent these released self-antigens from inducing effective anti-tumor immune responses. To overcome this challenge, we propose the use of immune checkpoint inhibitors to relieve T cell inhibition by immune checkpoints and enhance the anti-tumor immune response mediated by cryoablation. We used bilateral tumor-bearing mouse models and a specific cryoablation instrument to study the efficacy of cryoablation combined with PD-1 inhibitors in Lewis lung adenocarcinoma model mice. We found that cryoablation combined with PD-1 inhibitors significantly inhibited the growth of mouse lung adenocarcinoma, prolonged mouse survival, and enhanced the anti-tumor immune response. Moreover, this combined regimen could synergistically promote the activation and proliferation of T cells via the PI3K/AKT/mTOR pathway. The present study provides a strong theoretical basis for the clinical combination of cryoablation and PD-1 inhibitors.

A Comparative Study of Antitumor Immunity Induced by Radiofrequency Microwave and Cryoablation in Hepatocellular Carcinoma

PURPOSE

This study aimed to compare the immune responses induced by microwave ablation (MWA), radiofrequency ablation (RFA), and cryoablation (CRYO) in hepatocellular carcinoma (HCC) and identify differences in immune responses and the timing of immune changes.

MATERIALS AND METHODS

A bilateral subcutaneous model was established in C57 mice, and the successfully modeled mice were divided into the microwave (n = 15), radiofrequency (n = 15), CRYO (n = 15), control (n = 9), and blank groups (n = 3). Mice in the control group were dissected before ablation, whereas mice in the three ablation groups underwent ultrasound-guided ablation of one axillary tumor. Three mice were sacrificed and dissected at 1-4 weeks after ablation. After tissue processing, flow cytometry was used to detect the levels of CD8 + T and regulatory T (Treg) cells in the tissue, and western blotting was used to assess the level of programmed cell death ligand 1 (PD-L1) protein in the tumor tissue.

RESULTS

The pattern of immune changes after the three types of ablation was consistent, with immune changes occurring at 3-4 weeks. CRYO induced the most significant increase in the percentage of CD8 + T cells. There were no significant differences in the levels of Treg cells and the level of PD-L1 protein among the three types of ablation (p > 0.05), but the decline in Treg cells and PD-L1 protein level caused by CRYO was the most pronounced.

CONCLUSION

In the HCC mouse model, the immune changes following the three types of ablation were consistent, with immune changes occurring at 3-4 weeks. Among them, CRYO elicited the strongest adaptive immune response, and RFA outperformed MWA.

Potential of Thermal Ablation Combined with Immunotherapy in Peripheral Lung Tumors: A Review and Prospect

BACKGROUND

Lung tumors are prevalent malignancies associated with a high mortality rate, imposing significant medical and societal burdens. Although immunotherapy shows promise in improving survival, response rates are relatively modest. Thermal ablation can not only eliminate tumor cells directly but also enhance antitumor immunity response, thus manifesting a remarkable propensity to synergize with immunotherapy.

SUMMARY

In this review, we provided a brief overview of the application of thermal ablation in peripheral lung tumors. We summarized the patient selection of thermal ablation. We highlighted the potential of thermal ablation to augment the antitumor immune response, offering a promising avenue for combined therapies. We summarized studies assessing the synergistic effects of thermal ablation and immunotherapy in preclinical and clinical settings. Lastly, we underscored the urgent issues that warrant in-depth exploration when applying thermal ablation and immunotherapy to lung tumor patients.

KEY MESSAGES

This review emphasized the prospects of using thermal ablation combined with immunotherapy in patients with peripheral lung tumors. However, further research is needed to enhance and optimize this treatment strategy.

A novel in vitro model of clinical cryoablation to investigate the transition zone for focal tumor ablation

Cryoablation (CA) of solid tumors is highly effective at reducing tumor burden and eliminating small, early stage tumors. However, complete ablation is difficult to achieve and cancer recurrence is a significant barrier to treatment of larger tumors compared to resection. In this study, we explored the relationship between temperature, ice growth, and cell death using a novel in vitro model of clinical CA with the Visual-ICE (Boston Scientific) system, a clinically approved and widely utilized device. We found that increasing the duration of freezing from 1 to 2 min increased ice radius from 3.44 ± 0.13 mm to 5.29 ± 0.16 mm, and decreased the minimum temperature achieved from -22.8 ± 1.3 °C to -45.5 ± 7.9 °C. Furthermore, an additional minute of freezing increased the amount of cell death within a 5 mm radius from 42.5 ± 8.9% to 84.8 ± 1.1%. Freezing at 100% intensity leads to faster temperature drops and a higher level of cell death in the TRAMP-C2 mouse prostate cancer cell line, while lower intensities are useful for slow freezing, but result in less cell death. The width of transition zone between live and dead cells decreased by 0.4 ± 0.2 mm, increasing from one to two cycles of freeze/thaw cycles at 100% intensity. HMGB-1 levels significantly increased with 3 cycles of freeze/thaw compared to the standard 2 cycles. Overall, a longer freezing duration, higher freezing intensity, and more freeze thaw cycles led to higher levels of cancer cell death and smaller transition zones. These results have the potential to inform future preclinical research and to improve therapeutic combinations with CA.

Modern cancer therapy: cryoablation meets immune checkpoint blockade

Cryoablation, as a minimally invasive technology for the treatment of tumors, destroys target tumors with lethal low temperatures. It simultaneously releases a large number of tumor-specific antigens, pro-inflammatory cytokines, and nucleoproteins, known as "danger signals", activating the body's innate and adaptive immune responses. However, tumor cells can promote the inactivation of immune effector cells by reprogramming immune checkpoints, leading to the insufficiency of these antigens to induce an immune response capable of eradicating the tumor. Immune checkpoint blockers rejuvenate exhausted T cells by blocking immune checkpoints that induce programmed death of T cells, and are therefore considered a promising therapeutic strategy to enhance the immune effects of cryoablation. In this review, we provide a detailed explanation of the immunological mechanisms of cryoablation and articulate the theoretical basis and research progress of the treatment of cancer with cryoablation combined with immune checkpoint blockers. Preliminary data indicates that this combined treatment strategy exhibits good synergy and has been proven to be safe and effective.

Efficacy and Mechanism of Hypofractionation Radiotherapy Combined with PD-1 Inhibitors in a Model of Head and Neck Melanoma

Head and neck mucosal melanoma is one of the most common types of melanoma in China, but the prognosis is worse than other types, and there is no effective treatment plan to improve patient survival. This study analyzes the efficacy of hypofractionation radiotherapy combined with PD-1 inhibitor in the treatment of head and neck mucosal melanoma, as well as its impact on the tumor immune microenvironment. NPSG mice were used to construct a humanized bilateral lesion tumor model of the humanized immune system. The models were divided into an RT (8 Gy)+anti PD-1 group, an RT (2 GyX4)+anti PD-1 group, an Anti PD-1 group, an RT (8 Gy) group, and a blank group. Differences in efficacy and immune cells in blood, lymph nodes, and tumor tissues were compared between different treatment groups. The treatment effect of RT (8 Gy)+anti PD-1 was better than the other groups with a tumor growth inhibition value (TGI) over 60%. Significant recruitment and activation of CD8+T cells were found in the blood, lymph nodes, and tumor tissues and significantly inhibited the level of PD-1+CD8+T cells in the group of RT (8 Gy)+anti PD-1. This study confirmed the efficacy of hypofractionation radiotherapy combined with PD-1 inhibitors, which can inhibit tumor growth and produce distant effects. The appearance of a distant effect is related to the enhancement in the number and activity of CD8+T cells in the local tumor and peripheral blood and lymph nodes. This study confirms the therapeutic and immune regulatory effect of hypofractionation radiotherapy combined with PD-1 inhibitors.

Interventional Radiology Locoregional Therapies for Intrahepatic Cholangiocarcinoma

Surgical resection remains the cornerstone of curative treatment for intrahepatic cholangiocarcinoma (iCCA), but this option is only available to a small percentage of patients. For patients with unresectable iCCA, systemic therapy with gemcitabine and platinum-based agents represents the mainstay of treatment; however, the armamentarium has grown to include targeted molecular therapies (e.g., FGFR2 inhibitors), use of adjuvant therapy, liver transplantation in select cases, immunotherapy, and locoregional liver-directed therapies. Despite advances, iCCA remains a challenge due to the advanced stage of many patients at diagnosis. Furthermore, given the improving options for systemic therapy and the fact that the majority of iCCA patients succumb to disease progression in the liver, the role of locoregional therapies has increased. This review will focus on the expanding role of interventional radiology and liver-directed therapies in the treatment of iCCA.

Immune Effects of Cryoablation in Woodchuck Hepatocellular Carcinoma

Objectives

Local and systemic immune responses evoked by locoregional therapies such as cryoablation are incompletely understood. The aim of this study was to characterize cryoablation-related immune response and the capacity of immune drugs to augment immunity upon cryoablation for the treatment of hepatocellular carcinoma (HCC) using a woodchuck hepatocellular carcinoma model.

Materials and Methods

Twelve woodchucks chronically infected with woodchuck hepatitis virus and with hepatocellular carcinoma underwent imaging with contrast-enhanced CT. Partial cryoablation of tumors in three woodchucks was performed. Fourteen days after cryoablation, liver tissues were harvested and stained with H&E and TUNEL, and immune infiltrates were quantified. Peripheral blood mononuclear cells (PBMC) were collected from ablated and nonablated woodchucks, labeled with carboxyfluorescein succinimidyl ester (CFSE) and cultured with immune-modulating drugs, including a small PD-L1 antagonist molecule (BMS-202) and three TLR7/8 agonists (DSR 6434, GS-9620, gardiquimod). After incubation, cell replication and immune cell populations were analyzed by flow cytometry.

Results

Local immune response in tumors was characterized by an increased number of CD3+ T lymphocytes and natural killer cells in the cryolesion margin compared to other tumor regions. T regulatory cells were found in higher numbers in distant tumors within the liver compared to untreated or control tumors. Cryoablation also augmented the systemic immune response as demonstrated by higher numbers of PBMC responses upon immune drug stimulation in the cryoablation group.

Conclusions

Partial cryoablation augmented immune effects in both treated and remote untreated tumor microenvironments, as well as systemically, in woodchucks with HCC. Characterization of these mechanisms may enhance development of novel drug-device combinations for treatment of HCC.

Radiotherapy, photodynamic therapy, and cryoablation-induced abscopal effect: Challenges and future prospects

Local therapy modalities such as radiation therapy, photodynamic therapy, photothermal therapy, and cryoablation have been used to treat localized tumors for decades. The discovery of the abscopal effect causes a paradigm shift where local therapy also causes systemic effects and leads to the remission of nonirradiated tumors. The abscopal effect of radiation therapy, alone or in combination with other treatments, has been extensively studied over the last six decades. However, the results are unsatisfactory in producing robust, reproducible, and long-lasting systemic effects. Although immunotherapy and radiation therapy are promising in producing the abscopal effect, the abscopal effect's mechanism is still unclear, owing to various factors such as irradiation type and dose and cancer type. This article reviews the research progress, clinical and preclinical evidence of the abscopal effect by various local therapies alone and in combination with chemotherapy and immunotherapy, case reports, and the current challenges in producing the abscopal effect by various local therapies, focusing on radiotherapy, photodynamic therapy, cryoablation, and the prospects for obtaining a robust, reproducible, and long-lasting abscopal effect.

Exploration of the impact of multimode thermal therapy versus radiofrequency ablation on CD8+ T effector cells of liver malignancies based on single cell transcriptomics

Introduction

Multimode thermal therapy (MTT) is an innovative interventional therapy developed for the treatment of liver malignancies. When compared to the conventional radiofrequency ablation (RFA), MTT typically offers improved prognosis for patients. However, the effect of MTT on the peripheral immune environment and the mechanisms underlying the enhanced prognosis have yet to be explored. The aim of this study was to further investigate the mechanisms responsible for the difference in prognosis between the two therapies.

Methods

In this study, peripheral blood samples were collected from four patients treated with MTT and two patients treated with RFA for liver malignancies at different time points before and after the treatment. Single cell sequencing was performed on the blood samples to compare and analyze the activation pathways of peripheral immune cells following the MTT and RFA treatment.

Results

There was no significant effect of either therapy on the composition of immune cells in peripheral blood. However, the differential gene expression and pathway enrichment analysis demonstrated enhanced activation of T cells in the MTT group compared to the RFA group. In particular, there was a remarkable increase in TNF-α signaling via NF-κB, as well as the expression of IFN-α and IFN-γ in the CD8⁺ effector T (CD8⁺ Teff) cells subpopulation, when compared to the RFA group. This may be related to the upregulation of PI3KR1 expression after MTT, which promotes the activation of PI3K-AKT-mTOR pathway.

Conclusion

This study confirmed that MTT could more effectively activate peripheral CD8⁺ Teff cells in patients compared with RFA and promote the effector function, thus resulting in a better prognosis. These results provide a theoretical basis for the clinical application of MTT therapy.

Introduction to interventional oncology: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Interventional radiology (IR) is a valuable resource when caring for pediatric solid tumor patients. As minimally invasive, image-guided procedures become more relied upon to answer challenging diagnostic questions and provide alternative therapeutic options, IR is poised to become a contributing member of the multidisciplinary oncology team. Improved imaging techniques allow for better visualization during biopsy procedures, transarterial locoregional treatments have the potential to deliver targeted cytotoxic therapy while limiting systemic side effects, and percutaneous thermal ablation can be used to treat chemo-resistant tumors of various solid organs. Additionally, interventional radiologists are able to perform routine, supportive procedures for oncology patients that include central venous access placement, lumbar punctures, and enteric feeding tube placements with high levels of technical success and excellent safety profiles.

Progress in the cryoablation and cryoimmunotherapy for tumor

With the rapid advancement of imaging equipment and minimally invasive technology, cryoablation technology is being used more frequently in minimally invasive treatment of tumors, primarily for patients with early tumors who voluntarily consent to ablation as well as those with advanced tumors that cannot be surgically removed or cannot be tolerated. Cryoablation is more effective and secure for target lesions than other thermal ablation methods like microwave and radiofrequency ablation (RFA). The study also discovered that cryoablation, in addition to causing tumor tissue necrosis and apoptosis, can facilitate the release of tumor-derived autoantigens into the bloodstream and activate the host immune system to elicit beneficial anti-tumor immunological responses against primary. This may result in regression of the primary tumor and distant metastasis. The additional effect called " Accompanying effects ". It is the basis of combined ablation and immunotherapy for tumor. At present, there is a lot of research on the mechanism of immune response induced by cryoablation. Trying to solve the question: how positively induce immune response. In this review, we focus on: 1. the immune effects induced by cryoablation. 2. the effect and mechanism of tumor immunotherapy combined with cryoablation. 3.The clinical research of this combination therapy in the treatment of tumors.

Case report: Hilar metastasis of breast cancer: A single-center retrospective case-control study

Purpose

The lungs are a common metastatic organ in breast cancer, mainly due to blood metastasis. On imaging, most metastatic lesions show a peripheral round mass in the lung, occasionally with a hilar mass as the primary manifestation, showing burr and lobulation signs. This study aimed to investigate breast cancer patient's clinical characteristics and prognosis with two different metastatic sites in the lung.

Methods

We retrospectively analyzed patients admitted to the First Hospital of Jilin University between 2016 and 2021 diagnosed with breast cancer lung metastases. Forty breast cancer patients with hilar metastases (HM) and 40 patients with peripheral lung metastases (PLM) were matched 1:1 using a pairing method. To analyze the patient's prognosis, the clinical characteristics of patients with two different metastatic sites were compared using the chi-square test, Kaplan-Meier curve, and Cox proportional hazards model.

Results

The median follow-up time was 38 months (2-91 months). The median age of patients with HM was 56 years (25-75 years), and that of patients with PLM was 59 years (44-82 years). The median overall survival (mOS) was 27 months in the HM group and 42 months in the PLM group (p = 0.001). The results of the Cox proportional hazards model showed that the histological grade (hazard ratio = 2.741, 95% confidence interval 1.442-5.208, p = 0.002) was a prognostic factor in the HM group.

Conclusion

The number of young patients in the HM group was higher than that in the PLM group, with higher Ki-67 indexes and histological grades. Most patients had mediastinal lymph node metastasis, with shorter DFI and OS and poor prognosis.

Synergetic Thermal Therapy for Cancer: State-of-the-Art and the Future

As a safe and minimal-invasive modality, thermal therapy has become an effective treatment in cancer treatment. Other than killing the tumor cells or destroying the tumor entirely, the thermal modality results in profound molecular, cellular and biological effects on both the targeted tissue, surrounding environments, and even the whole body, which has triggered the combination of the thermal therapy with other traditional therapies as chemotherapy and radiation therapy or new therapies like immunotherapy, gene therapy, etc. The combined treatments have shown encouraging therapeutic effects both in research and clinic. In this review, we have summarized the outcomes of the existing synergistic therapies, the underlying mechanisms that lead to these improvements, and the latest research in the past five years. Limitations and future directions of synergistic thermal therapy are also discussed.

Advances in locoregional therapy for hepatocellular carcinoma combined with immunotherapy and targeted therapy

Locoregional therapies (LRTs) of hepatocellular carcinoma (HCC) represented by ablation and TACE has become the main means for the clinical treatment of unresectable HCC. Among these, TACE is used throughout the stage Ib to IIIb of HCC treatment. In recent years, immunotherapy led by immune checkpoint inhibitors has become a hot direction in clinical research. At the same time, targeted drugs such as Sorafenib and Apatinib have played an important role in the treatment and complementary therapy of advanced HCC, and their clinical application has been quite mature. HCC is the sixth most common malignant tumor in the world. When it comes to its treatment, different therapies have different indications, and their individual efficacies are not satisfactory, which makes the exploration of the use of combination therapy in HCC treatment become a new trend. In this paper, the status of the three therapies and the progress of their combined application are briefly reviewed.

Abscopal Effect of Frozen Autograft Reconstruction Combined with an Immune Checkpoint Inhibitor Analyzed Using a Metastatic Bone Tumor Model

We evaluated the abscopal effect of re-implantation of liquid nitrogen-treated tumor-bearing bone grafts and the synergistic effect of anti-PD-1 (programmed death-1) therapy using a bone metastasis model, created by injecting MMT-060562 cells into the bilateral tibiae of 6-8-week-old female C3H mice. After 2 weeks, the lateral tumors were treated by excision, cryotreatment using liquid nitrogen, excision with anti-PD-1 treatment, and cryotreatment with anti-PD-1 treatment. Anti-mouse PD-1 4H2 was injected on days 1, 6, 12, and 18 post-treatment. The mice were euthanized after 3 weeks; the abscopal effect was evaluated by focusing on growth inhibition of the abscopal tumor. The re-implantation of frozen autografts significantly inhibited the growth of the remaining abscopal tumors. However, a more potent abscopal effect was observed in the anti-PD-1 antibody group. The number of CD8+ T cells infiltrating the abscopal tumor and tumor-specific interferon-γ (IFN-γ)-producing spleen cells increased in the liquid nitrogen-treated group compared with those in the excision group, with no significant difference. The number was significantly higher in the anti-PD-1 antibody-treated group than in the non-treated group. Overall, re-implantation of tumor-bearing frozen autograft has an abscopal effect on abscopal tumor growth, although re-implantation of liquid nitrogen-treated bone grafts did not induce a strong T-cell response or tumor-suppressive effect.

Abscopal effect in radioimmunotherapy

Abscopal effect is an interesting phenomenon in radiobiology that causes activation of immune system against cancer cells. Traditionally, this phenomenon was known as a suppressor of non-irradiated tumors or metastasis. However, it can be used as a stimulator of the immune system against primary tumor during radiotherapy. Immunotherapy, a novel tumor therapy modality, also triggers immune system against cancer. To date, some immunotherapy types have been developed. However, immune checkpoint blockade is a more common modality and some drugs have been approved by the FDA. Studies have shown that radiotherapy or immunotherapy administered alone have low efficiency for tumor control. However, their combination has a more potent anti-tumor immunity. For this aim, it is important to induce abscopal effect in primary tumors, and also use appropriate drugs to target the mechanisms involved in the exhaustion of cytotoxic CD8+T lymphocytes (CTLs) and natural killer (NK) cells. Among the different radiotherapy techniques, stereotactic body radiation therapy (SBRT) with some few fractionations is the best choice for inducing abscopal effect. On the other hand, programmed cell death 1 (PD-1) is known as one of the best targets for triggering anti-tumor immunity. This combination is known as the best choice among various strategies for radioimmunotherapy. However, there is the need for other strategies to improve the duration of immune system's activity within tumor microenvironment (TME). In this review, we explain the cellular and molecular mechanisms behind abscopal effect by radiotherapy and evaluate the molecular targets which induce potent anti-tumor immunity.