Postablation Immune Microenvironment: Synergy between Interventional Oncology and Immuno-oncology

Dynamic Changes in the Immune Microenvironment in Tumor-Draining Lymph Nodes of a Lewis Lung Cancer Mouse Model After Microwave Ablation

Purpose

Microwave ablation (MWA) is a minimally invasive technique for treating lung cancer. It can induce immune response; however, its effect on the immune microenvironment in tumor-draining lymph nodes (TdLN) is not well understood. This study aims to identify changes in the immune microenvironment in TdLN following MWA in a Lewis lung cancer (LLC) mouse model.

Methods

LLC mouse model was established and followed by MWA. TdLN were collected at various time points, including pre-MWA and days 1, 2, 4, and 8 post-MWA. Flow cytometry was used to determine the frequencies of CD4+ T cells, CD8+ T cells, regulatory T (Treg) cells, natural killer (NK) cells, dendritic cells (DCs) and other immune cells in the TdLN. Certain cytokines were also detected.

Results

Compared with pre-MWA, the frequency of CD4+ T cells significantly increased from day 1 to day 8 post-MWA. The frequency of CD8+ T cells decreased significantly on days 2 and 4, but no significant changes occurred on days 1 and 8. Significant decreases in the frequencies of Treg cells and Klrg1+ Treg cells were observed from day 1 to day 4. On days 4 and 8, there was a significant increase in the frequency of NK cells. The frequency of resident cDC2 significantly increased on day 4, whereas CD11b+ migratory cDCs increased on day 1. Additionally, on day 4, a notable rise was observed in the frequency of NK cells secreting IFN-γ, while on day 8, there was a significant increase in the frequency of CD8+ T cells secreting both IFN-γ and TNF-α.

Conclusion

MWA of lung cancer can alter the immune microenvironment in the TdLN, triggering immune responses. These changes are particularly evident and intricate within the initial 4 days post-MWA. Treatment combined with MWA within a certain period may significantly enhance anti-tumor immunity.

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.

Pulsed Electric Field Ablation versus Radiofrequency Thermal Ablation in Murine Breast Cancer Models: Anticancer Immune Stimulation, Tumor Response, and Abscopal Effects

PURPOSE

To compare the immune response and survival after size-matched radiofrequency (RF) ablation and a proprietary form of pulsed electric field (PEF) ablation in murine tumors.

MATERIAL AND METHODS

Orthotopically inoculated EMT6 or 4T1 murine tumors received sham, RF ablation, or PEF ablation. 4T1 tumor ablations included subgroups with intraperitoneal checkpoint inhibition immunotherapy (αPD-1). Blood was collected for cytokine profiling and flow cytometry. Tumor size was measured and survival was monitored. Tumor samples were processed for histology, immunohistochemistry, flow cytometry, and cytokine profiling. Lungs were collected from 4T1-bearing mice for hematoxylin and eosin histology to assess metastatic spread and abscopal effect induced by ablation.

RESULTS

PEF elicited distinct immunomodulatory effects, with clear differences in serum and tumor cytokine profiles compared with RF ablation, including intratumoral downregulation of vascular endothelial growth factor, hypoxia-inducible factor 1α, c-MET, interleukin-10, Ki67, and tumor necrosis factor-α (all P < .05). PEF increased innate immune activation, with enhanced recruitment of dendritic cells, M1 macrophages, and natural killer cells coupled with a reduction in M2 macrophages and myeloid-derived suppressor cells (all P < .05). Concurrently, PEF strengthened adaptive immunity compared with RF ablation, characterized by increased antigen-specific T cells and decreased regulatory T cells (all P < .05). PEF stalled tumor growth and increased survival at the end of the study (≥4× versus RFA). Finally, PEF promoted an abscopal effect of clearing metastases in the lungs, which was stronger in combination with αPD-1 than with PEF alone.

CONCLUSIONS

The proprietary form of PEF used in this study evoked a preferential immunostimulatory profile versus RF ablation thermal ablation in mice, with implications for enhancing the therapeutic effectiveness of checkpoint inhibition immunotherapy for immunotherapy-unresponsive tumors.

Percutaneous image-guided ablation for hepatic metastases

The presence of hepatic metastases indicates advanced disease and is associated with significant morbidity and mortality, especially when the hepatic disease is not amenable to locoregional treatments. The primary tumour of origin, the distribution and extent of metastatic disease, the underlying liver reserve, the patient performance status and the presence of comorbidities are factors that determine whether a patient will benefit from hepatectomy or local curative-intent treatments. For patients with metastatic colorectal cancer, the most common primary cancer that spreads to the liver, several studies have demonstrated a survival benefit for patients who can be treated with hepatectomy and/or percutaneous ablation, compared to those treated with chemotherapy alone. Despite advances in surgical techniques increasing the percentage of patients eligible for surgery, most patients have unresectable disease or are poor surgical candidates. Percutaneous ablation can be used to provide local disease control and prolong survival for both surgical and non-surgical candidates. This is typically offered to patients with small hepatic metastases that can be ablated with optimal (≥10 mm) or at least adequate minimum ablation margins (≥5 mm), as high local tumour control rates can be achieved for these patients which are comparable to surgical resection. This review summarizes available evidence and outcomes following percutaneous ablation of the most frequently encountered types of hepatic metastases in the clinical practice of interventional oncology. Patient selection, technical considerations, follow-up protocols and oncologic outcomes are presented and discussed.

Potential biomarkers for predicting immune response and outcomes in lung cancer patients undergoing thermal ablation

Thermal ablation is a promising alternative treatment for lung cancer. It disintegrates cancer cells and releases antigens, followed by the remodeling of local tumor immune microenvironment and the activation of anti-tumor immune responses, enhancing the overall effectiveness of the treatment. Biomarkers can offer insights into the patient's immune response and outcomes, such as local tumor control, recurrence, overall survival, and progression-free survival. Identifying and validating such biomarkers can significantly impact clinical decision-making, leading to personalized treatment strategies and improved patient outcomes. This review provides a comprehensive overview of the current state of research on potential biomarkers for predicting immune response and outcomes in lung cancer patients undergoing thermal ablation, including their potential role in lung cancer management, and the challenges and future directions.

In-situ tumor vaccination by percutaneous ablative therapy and its synergy with immunotherapeutics: An update on combination therapy

Percutaneous tumor ablation is now a widely accepted minimally invasive local treatment option offered by interventional radiology and applied to various organs and tumor histology types. It utilizes extreme temperatures to achieve irreversible cellular injury, where ablated tumor interacts with surrounding tissue and host via tissue remodeling and inflammation, clinically manifesting as post-ablation syndrome. During this process, in-situ tumor vaccination occurs, in which tumor neoantigens are released from ablated tissue and can prime one’s immune system which would favorably affect both local and remote site disease control. Although successful in priming the immune system, this rarely turns into clinical benefits for local and systemic tumor control due to intrinsic negative immune modulation of the tumor microenvironment. A combination of ablation and immunotherapy has been employed to overcome these and has shown promising preliminary results of synergistic effect without significantly increased risk profiles. The aim of this article is to review the evidence on post-ablation immune response and its synergy with systemic immunotherapies.

[Current Status and Progress of Thermal Ablation Combined with Immunotherapy for Lung Tumors]

Recent studies have shown that tumor immune microenvironment is closely related to tumor progression, metastasis, recurrence and response to treatment. Some immunotherapies also offer hope for cancer patients. However, the efficacy of tumor immunotherapy is uncertain and has some side effects. In order to enhance its efficacy, tumor immunotherapy combined with tumor thermal ablation has been studied. Thermal ablation has the advantages of minimally invasive, rapid recovery, safety, fewer complications, conformation, reliable effect, repeatable, low cost, and has become the fourth tumor treatment measure after surgery, radiotherapy, and drug therapy. It can directly kill tumor cells and modulate the immune system through a variety of mechanisms, although the corresponding mechanisms are not well understood, but combined tumor immunotherapy has been proposed to treat several solid malignancies. In this review, the current status and progress of thermal ablation combined with immunotherapy for lung tumor were reviewed, and further studies on the efficacy and safety of thermal ablation combined with immunotherapy were expected.
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An Exploratory Analysis of Changes in Circulating Plasma Protein Profiles Following Image-Guided Ablation of Renal Tumours Provides Evidence for Effects on Multiple Biological Processes

Simple Summary

Ablation techniques use extremely hot or cold temperatures to kill small cancers. It is now known that in addition to killing the cancer cells, the ablation treatment may stimulate an immune response in patients against the cancer cells, acting like a vaccine. As a result, there is now interest in combining ablation together with drugs that target the immune system of patients with cancer to enhance the effects of both treatments. In order to develop such combined treatments and test them in clinical trials, we need to understand more about their effects so trials can be optimally designed to be most effective. We have analysed 164 circulating proteins in the blood from patients with small renal tumours undergoing ablation treatment to understand more about the effects of ablation on the patient, both at the level of the effects on the cancer cells and the response of the patients.

Abstract

Further biological understanding of the immune and inflammatory responses following ablation is critical to the rational development of combination ablation-immunotherapies. Our pilot exploratory study evaluated the circulating plasma protein profiles after image-guided ablation (IGA) of small renal masses to determine the resultant systemic effects and provide insight into impact both on the tumour and immune system. Patients undergoing cryotherapy (CRYO), radiofrequency ablation (RFA) or microwave ablation (MWA) for small renal tumours were recruited. Blood samples were obtained at four timepoints; two baselines prior to IGA and at 24 h and 1–3 months post-IGA, and a panel of 164 proteins measured. Of 55 patients recruited, 35 underwent ablation (25 CRYO, 8 RFA, 2 MWA) and biomarker measurements. The most marked changes were 24 h post-CRYO, with 29 proteins increasing and 18 decreasing significantly, principally cytokines and proteins involved in regulating inflammation, danger-associated molecular patterns (DAMPs), cell proliferation, hypoxic response, apoptosis and migration. Intra-individual variation was low but inter-individual variation was apparent, for example all patients showed increases in IL-6 (1.7 to 29-fold) but only 50% in CD27. Functional annotation analysis highlighted immune/inflammation and cell proliferation/angiogenesis-related clusters, with interaction networks around IL-6, IL-10, VEGF-A and several chemokines. Increases in IL-8, IL-6, and CCL23 correlated with cryoprobe number (p = 0.01, r_s = 0.546; p = 0.009, r_s = 0.5515; p = 0.005, r_s = 0.5873, respectively). This initial data provide further insights into ablation-induced biological changes of relevance in informing trial design of immunotherapies combined with ablation.

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.

Interventional Techniques for Bone and Musculoskeletal Soft Tissue Tumors: Current Practices and Future Directions - Part I. Ablation

Musculoskeletal (MSK) image-guided oncologic intervention is an established field within radiology. Numerous studies have described its clinical benefits, safety, cost effectiveness, patient satisfaction, and improved quality of life, thereby establishing image-guided oncologic intervention as a preferred pathway in treating patients presenting with specific benign MSK tumors. But there is a paradigm shift on the horizon because these techniques may also support established pillars (surgery, systemic treatment, radiotherapy) in the treatment of malignant MSK tumors. Unlike benign tumors, where they are used as primary therapy lines with curative intent, such interventions can be selected for malignant tumors as adjuvant treatment in painful or unstable bone or soft tissue lesions or as more palliative therapy strategies. Using examples from our clinical practices, we elaborate on the benefits of applying a multidisciplinary approach (traditionally involving MSK radiologists, oncologists, orthopaedic surgeons, microbiologists, pathologists, physiotherapists, and pain management experts), ideally within a sarcoma treatment center to deliver a patient-specific therapy plan and illustrate methods to assess the benefits of this model of care.In this article, we review the current repertoire of ablation techniques, demonstrate why such procedures offer value-based alternatives to conventional treatments of specific tumors, and reflect on future directions. Additionally, we review the advantages and limitations of each technique and offer guidance to improve outcomes.

[Thermoablation : Friend and foe of immunotherapy]

BACKGROUND

Evidence from multiple studies have shown the potential of thermal ablative therapies to induce regression of metastases and tumors which are distant from the treated metastases-within the same organ or even in other organs-the so-called abscopal effect. Unfortunately, this effect is most often weak and not always reproducible. Recent developments in systemic therapies showed that immunomodulating drugs are of major interest in patient-tailored tumor therapy due to the fact that they are able to enhance the treatment effect of conventional chemotherapy. Furthermore, several studies and reports showed that these immunomodulating therapies are also able to enhance the response of the immune system to the tumor-if combined with local ablative therapies-and trigger a systemic antitumor response. Unfortunately, there is also evidence that effects caused by thermal ablation can hamper the immune system and, therefore, increase tumor growth and tumor spread.

OBJECTIVES

In this article, the effects of thermal ablation in general are described, different (thermo-)ablative techniques are presented and a perspective of combination therapies is given.

Direct treatment versus indirect: Thermo-ablative and mild hyperthermia effects

Hyperthermia is a rapidly growing field in cancer therapy and many advances have been made in understanding and applying the mechanisms of hyperthermia. Secondary effects of hyperthermia have been increasingly recognized as important in therapeutic effects and multiple studies have started to elucidate their implications for treatment. Immune effects have especially been recognized as important in the efficacy of hyperthermia treatment of cancer. Both thermo-ablative and mild hyperthermia activate the immune system, but mild hyperthermia seems to be more effective at doing so. This may suggest that mild hyperthermia has some advantages over thermo-ablative hyperthermia and research into immune effects of mild hyperthermia should continue. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.