Immune Adjuvant Activity of Pre-Resectional Radiofrequency Ablation Protects against Local and Systemic Recurrence in Aggressive Murine Colorectal Cancer

Endoluminal radiofrequency ablation in patients with malignant biliary obstruction: a randomised trial

BACKGROUND

Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique.

DESIGN

In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280).

RESULTS

A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups.

CONCLUSION

A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction.

TRIAL REGISTRATION NUMBER

NCT03166436.

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.

Percutaneous Radiofrequency Ablation Combined With Chemotherapy Versus Chemotherapy Only for Ovarian Cancer Liver Metastasis

Purpose

To compare the feasibility and efficacy of radiofrequency ablation (RFA) combined with chemotherapy and chemotherapy alone in patients with ovarian cancer liver metastasis (OCLM).

Methods

In this retrospective study, a total of 60 patients diagnosed with OCLM between May 2015 to February 2017 were included. All patients with ovarian cancer received chemotherapy and primary cytoreductive surgery before. Thirty patients underwent RFA and chemotherapy, and thirty patients only took chemotherapy. The overall survival (OS), CA-125 levels, and serum AST and ALT levels were compared between the two groups.

Results

In the RFA group, the 1-,2-, and 3-year OS rates after RFA were 93.3%, 80.0%, and 53.3%, respectively. Serum AST and ALT levels were both elevated after RFA (p=0.0004, p<0.0001). In the chemotherapy group, the 1-,2-, and 3-year OS rates were 79.5%, 60.1%, and 42.1%, respectively. Levels of serum AST and ALT were stable. CA-125 levels for both groups were also available.

Conclusion

Based on our analysis of a single institution’s series of patients with OCLM, RFA could be a feasibly effective option in the management of OCLM.

Current advances in immune checkpoint inhibitor combinations with radiation therapy or cryotherapy for breast cancer

PURPOSE

Immune checkpoint inhibition (ICI) has demonstrated clinically significant efficacy when combined with chemotherapy in triple negative breast cancer (TNBC). Although many patients derived benefit, others do not respond to immunotherapy, therefore relying upon innovative combinations to enhance response. Local therapies such as radiation therapy (RT) and cryotherapy are immunogenic and potentially optimize responses to immunotherapy. Strategies combining these therapies and ICI are actively under investigation. This review will describe the rationale for combining ICI with targeted local therapies in breast cancer.

METHODS

A literature search was performed to identify pre-clinical and clinical studies assessing ICI combined with RT or cryotherapy published as of August 2021 using PubMed and ClinicalTrials.gov.

RESULTS

Published studies of ICI with RT and IPI have demonstrated safety and signals of early efficacy.

CONCLUSION

RT and cryotherapy are local therapies that can be integrated safely with ICI and has shown promise in early trials. Randomized phase II studies testing both of these approaches, such as P-RAD (NCT04443348) and ipilimumab/nivolumab/cryoablation for TNBC (NCT03546686) are current enrolling. The results of these studies are paramount as they will provide long term data on the safety and efficacy of these regimens.

Neoadjuvant in situ immunomodulation enhances systemic antitumor immunity against highly metastatic tumors

Neoadjuvant immunotherapy, given before surgical resection, is a promising approach to develop systemic antitumor immunity for the treatment of high-risk resectable disease. Here, using syngeneic and orthotopic mouse models of triple-negative breast cancer, we have tested the hypothesis that generation of tumor-specific T-cell responses by induction and activation of tumor-residing Batf3-dependent conventional type 1 dendritic cells (cDC1) before resection improves control of distant metastatic disease and survival. Mice bearing highly metastatic orthotopic tumors were treated with a combinatorial in situ immunomodulation (ISIM) regimen comprised of intratumoral administration of Flt3L, local radiotherapy, and in situ TLR3/CD40 stimulations, followed by surgical resection. Neoadjuvant ISIM generated tumor-specific CD8+ T cells that infiltrated into distant non-irradiated metastatic sites, which delayed the progression of lung metastases and improved survival after the resection of primary tumors. The efficacy of neoadjuvant ISIM was dependent on de novo adaptive T-cell immunity elicited by Batf3-dependent DCs and was enhanced by increasing dose and fractionation of radiotherapy, and early surgical resection after the completion of neoadjuvant ISIM. Importantly, neoadjuvant ISIM synergized with PD-L1 blockade to improve control of distant metastases and prolong survival, while removal of tumor-draining lymph nodes abrogated the antimetastatic efficacy of neoadjuvant ISIM. Our findings illustrate the therapeutic potential of neoadjuvant multimodal intralesional therapy for the treatment of resectable tumors with high risk of relapse.

MTL-CEBPA Combined with Immunotherapy or RFA Enhances Immunological Anti-Tumor Response in Preclinical Models

The transcription factor CEBPA is a master regulator of liver homeostasis, myeloid cell differentiation and is downregulated in several oncogenic diseases. MTL-CEBPA is a small activating RNA drug which upregulates gene expression of CEBPA for treatment of hepatocellular carcinoma (HCC). We investigate whether MTL-CEBPA has immune modulatory effects by combining MTL-CEBPA with an anti-PD-1 checkpoint inhibitor (CPI) and/or radiofrequency ablation (RFA) in two preclinical models. First, mice with two flanks of HCC tumors (BNL) were treated with combinations of RFA (right flank), anti-PD-1 or MTL-CEBPA. The reduction of the left flank tumors was most pronounced in the group treated with RFA+anti-PD1+MTL-CEBPA and 7/8 animals responded. This was the only group with a significant increase in CD8+ and CD49b+/CD45+ tumor infiltrating lymphocytes (TIL). Second, a combination of anti-PD-1+MTL-CEBPA was tested in a CT26 colon cancer model and this treatment significantly reduced tumor size, modulated the tumor immune microenvironment and increased TILs. These data suggest a clinical role for combination treatment with CPIs, RFA and MTL-CEBPA through synergistic priming of the immune tumor response, enabling RFA and CPIs to have a pronounced anti-tumor effect including activity in non-treated tumors in the case of RFA.

US-guided high-intensity focused ultrasound (HIFU) of abdominal tumors: outcome, early ablation-related laboratory changes and inflammatory reaction. A single-center experience from Germany

INTRODUCTION

High-intensity focused ultrasound (HIFU) is an innovative noninvasive procedure for local ablation of different benign and malignant tumors. Preliminary data of animal studies suggest an ablation-associated immune response after HIFU that is induced by cell necrosis and release of intracellular components. The aim of this study is to evaluate if a HIFU-induced early sterile inflammatory reaction is initiated after ablation of uterine fibroids (UF) and pancreatic carcinoma (PaC) which might contribute to the therapeutic effect.

MATERIAL AND METHODS

A hundred patients with PaC and 30 patients with UF underwent US-guided HIFU treatment. Serum markers of inflammation (leukocytes, CRP, IL-6) and LDH in both collectives as well as tumor markers CA 19-9, CEA and CYFRA in PaC patients were determined in sub-cohorts before and directly after HIFU (0, 2, 5 and 20 h post-ablation) as well as at 3, 6, 9 and 12 months follow-up. Peri-/post interventional imaging included contrast-enhanced MRI of both cohorts and an additional CT scan of PaC patients.

RESULTS

An early post-ablation inflammatory response was observed in both groups with a significant increase of leukocytes, CRP and LDH within the first 20 h after HIFU. Interestingly, IL-6 was increased at 20 h after HIFU in PaC patients. A significant reduction of tumor volumes was observed during one year follow-up (p < .001) for both tumor entities demonstrating effective treatment outcome.

CONCLUSION

Tumor ablation with HIFU induces an early sterile inflammation that might serve as a precondition for long-term tumor immunity and a sustainable therapeutic effect.

Thermal ablation in non-small cell lung cancer: a review of treatment modalities and the evidence for combination with immune checkpoint inhibitors

Lung cancer is the leading cause of cancer death worldwide, with approximately 1.6 million cancer related deaths each year. Prognosis is best in patients with early stage disease, though even then five-year survival is only 55% in some groups. Median survival for advanced non-small cell lung cancer (NSCLC) is 8–12 months with conventional treatment. Immune checkpoint inhibitor (ICI) therapy has revolutionised the treatment of NSCLC with significant long-term improvements in survival demonstrated in some patients with advanced NSCLC. However, only a small proportion of patients respond to ICI, suggesting the need for further techniques to harness the potential of ICI therapy. Thermal ablation utilizes the extremes of temperature to cause tumour destruction. Commonly used modalities are radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA). At present thermal ablation is reserved for curative-intent therapy in patients with localized NSCLC who are unable to undergo surgical resection or stereotactic ablative body radiotherapy (SABR). Limited evidence suggests that thermal ablative modalities can upregulate an anticancer immune response in NSCLC. It is postulated that thermal ablation can increase tumour antigen release, which would initiate and upregulated steps in the cancer immunity cycle required to elicit an anticancer immune response. This article will review the current thermal ablative techniques and their ability to modulate an anti-cancer immune response with a view of using thermal ablation in conjunction with ICI therapy.

Temperature Plays an Essential Regulatory Role in the Tumor Immune Microenvironment

In recent years, emerging immunotherapy has been included in various malignant tumor treatment standards. Temperature has been considered to affect different pathophysiological reactions such as inflammation and cancer for a long time. However, in tumor immunology research, temperature is still rarely considered a significant variable. In this review, we discuss the effects of room temperature, body temperature, and the local tumor temperature on the tumor immune microenvironment from multiple levels and perspectives, and we discuss changes in the body's local and whole-body temperature under tumor conditions. We analyze the current use of ablation treatment-the reason for the opposite immune effect. We should pay more attention to the therapeutic potential of temperature and create a better antitumor microenvironment that can be combined with immunotherapy.

The Role of Neoadjuvant Chemotherapy in Locally Advanced Colon Cancer

Neoadjuvant systemic therapy has many potential advantages over up-front surgery, including tumor downstaging, early treatment of micrometastatic disease, and providing an in vivo test of tumor biology. Due to these advantages, neoadjuvant therapy is becoming the standard of care for an increasing number of tumor types. Currently, colon cancer patients are still routinely treated with up-front surgery, and neoadjuvant systemic therapy is not yet standard. Limitations to widespread use of neoadjuvant therapy have included inaccurate radiological staging, concerns about tumor progression while undergoing preoperative treatment rendering a patient incurable, and a lack of randomized data demonstrating benefit. However, there is great interest in neoadjuvant chemotherapy, and a number of trials are under way. Early follow up of the first phase III trial of neoadjuvant chemotherapy for colon cancer demonstrated tumor downstaging and suggested an improvement in disease-free survival with neoadjuvant chemotherapy, and it is hoped that this will translate into longer-term overall survival benefit. Clinicians should closely watch this developing field, consider the option of neoadjuvant chemotherapy for colon cancer patients, and actively seek out opportunities for their patients to participate in ongoing clinical trials to further inform this field in future.

Antitumor, Immunomodulatory and Antiangiogenic Efficacy of Medicinal Mushroom Extract Mixtures in Advanced Colorectal Cancer Animal Model

Due to frequent drug resistance and/or unwanted side-effects during conventional and targeted cancer treatments, development of multi-target therapies is an important research field. Medicinal mushrooms’ isolated specific compounds and mushroom extracts have been already proven as non-toxic multi-target inhibitors of specific oncogenic pathways, as well as potent immunomodulators. However, research on antitumor effects of multiple-species extract mixtures was limited so far. The aim of this study was therefore, a study of medicinal mushroom preparations AGARIKON.1 and AGARIKON PLUS on colorectal cell lines in vitro and colorectal mice model in vivo. We found a significant antiproliferative and pro-apoptotic effect of tested medicinal mushroom preparations on colorectal (HCT-116, SW620) tumor cell lines, while the effect on human fibroblast cell line (WI-38) was proliferative emphasizing a specificity towards tumor cell lines. We further investigated the effect of the medicinal mushroom preparations AGARIKON.1 and AGARIKON PLUS in various combinations with conventional cytostatic drug 5-fluorouracil in the advanced metastatic colorectal cancer mouse model CT26.WT. AGARIKON.1 and AGARIKON PLUS exhibited immunostimulatory and antiangiogenic properties in vivo which resulted in significantly increased survival and reduction in tumor volume. The antitumor effects of AGARIKON.1 and AGARIKON PLUS, with or without 5-fluorouracil, are based on M1 macrophage polarization enhancement, inhibition of M2 and tumor-associated macrophage (TAM) polarization, effects on T helper cell Th1/Th2/Th17 cytokine profiles, direct inhibition of CT26.WT tumor growth, inhibition of vascular endothelial growth factors (VEGF) and metalloproteinases 2 and 9 (MMP-2 and MMP-9) modulation. The administration of AGARIKON.1 and AGARIKON PLUS did not show genotoxic effect. This data provides good basis for an expanded translational study.

Treatment With Medicinal Mushroom Extract Mixture Inhibits Translation and Reprograms Metabolism in Advanced Colorectal Cancer Animal Model as Evidenced by Tandem Mass Tags Proteomics Analysis

Colorectal cancer (CRC) is the third most frequent cancer type in both males and females, with about 35% of patients being diagnosed in stage IV metastatic disease. Despite advancements in treatment, life expectancy in patients with metastatic disease is still not satisfying. Due to frequent drug resistance during conventional and targeted cancer treatments, the development and testing of multi-target therapies is an important research field. Medicinal mushrooms specific isolated compounds as well as complex extract mixtures have been studied in depth, and many mushroom species have been proven to be non-toxic multi-target inhibitors of specific oncogenic pathways, as well as potent immunomodulators. In this study, we have performed a tandem mass tags qualitative and quantitative proteomic analyses of CT26.WT colon cancer tumor tissues from Balb/c mice treated with the studied medicinal mushroom extract mixture, with or without 5-fluorouracil. Besides significantly improved survival, obtained results reveal that Agarikon.1 alone, and in combination with 5-fluorouracil exert their anticancer effects by affecting several fundamental processes important in CRC progression. Bioinformatic analysis of up- and downregulated proteins revealed that ribosomal biogenesis and translation is downregulated in treatment groups, while the unfolded protein response (UPR), lipid metabolism and tricarboxylic acid cycle (TCA) are upregulated. Moreover, we found that many known clinical biomarkers and protein clusters important in CRC progression and prognosis are affected, which are a good basis for an expanded translational study of the herein presented treatment.

Immunological combination treatment holds the key to improving survival in pancreatic cancer

Advances in surgery, peri-operative care and systemic chemotherapy have not significantly improved the prognosis of pancreatic cancer for several decades. Early clinical trials of immunotherapy have yielded disappointing results proposing other means by which the tumour microenvironment serves to decrease the immune response. Additionally, the emergence of various subtypes of pancreatic cancer has emerged as a factor for treatment responses with immunogenic subtypes carrying a better prognosis. Herein we discuss the reasons for the poor response to checkpoint inhibitors and outline a rationale why combination treatments are likely to be most effective. We review the therapies which could provide optimal synergistic effects to immunotherapy including chemotherapy, agents targeting the stroma, co-stimulatory molecules, vaccinations and methods of immunogenic tumour priming including radiofrequency ablation. Finally, we discuss reasons why peri-operative and in particular neoadjuvant combination treatments are likely to be most effective and should be considered for early clinical trials.

Surgical therapy for breast cancer liver metastases

Breast cancer is the most commonly diagnosed cancer in females worldwide. If diagnosed early, patients generally have good outcomes. However, approximately 20% to 30% of all women diagnosed with breast cancer develop metastatic disease. Metastatic breast cancer is incurable, but there is growing evidence that resection or other local therapy for breast cancer liver metastases (BCLM) may improve survival. We aimed to review indications for and outcomes of perioperative liver resection and other local therapies for BCLM. In this series, we reviewed 11 articles (605 patients) focusing on surgical resection and 7 articles (266 patients) describing radiofrequency ablation (RFA) for BCLM. Median disease-free survival (DFS) after surgical resection was 23 months (range, 14–29 months) and median overall survival (OS) was 39.5 months (range, 26–82 months). One, 3- and 5-year survivals were 89.5%, 70%, and 38%, respectively. The factors favoring better outcomes are hormone receptor positive primary breast cancer status, R0 resection, no extrahepatic metastases (EHM), small BCLM, and solitary liver metastases. On the other hand, the median DFS with RFA was 11 months, median OS was 32 months, and the 3- and 5-year OS were 43% and 27%, respectively. The clinical features that are indications for RFA are smaller tumor and higher EHM rate than those favoring surgical resection (2.4 vs. 4.0 cm and 46% vs. 27%). The merits of RFA are its high technical success rate, low morbidity, short hospital stay, and that it can be repeated. Although results are as yet limited, in carefully selected patients, resection or other local therapies such as RFA, render BCLM potentially provide prognostic improvement.

Immune response activation following hyperthermic intraperitoneal chemotherapy for peritoneal metastases: A pilot study

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal metastases (PM) is considered to be feasible, safe and to improve survival.

AIM

To investigate whether an immune response is activated following HIPEC for PM.

METHODS

Six patients were enrolled in this study. Peripheral blood samples were obtained from each patient prior to (day 0) and post-procedure (day 30), and used to evaluate the number of CD3⁺ total, CD3⁺/CD4⁺ T-Helper, CD3⁺/CD8⁺ cytotoxic T, CD3⁺/CD56⁺ natural killer and CD19⁺ B lymphocyte numbers, and CD4⁺: CD8⁺ T lymphocyte ratios.

RESULTS

The total numbers of CD3⁺, CD3⁺/CD4⁺ T-Helper, CD3⁺/CD8⁺ cytotoxic T, CD3⁺/CD56⁺ natural killer and CD19⁺ B lymphocytes, and CD4⁺: CD8⁺ lymphocyte ratios were increased in all but one patient 30 d following the cytoreductive surgery-HIPEC procedure, and these increases were significant (P ≤ 0.05) for CD3⁺/CD4⁺ T Helper and CD3⁺/CD8⁺ cytotoxic T lymphocyte numbers.

CONCLUSION

This report provides the first evidence that HIPEC exhibits immunomodulating activity in PM patients, resulting in generalized activation of the adaptive immune response. Moreover, the majority of lymphocyte populations increased following HIPEC and continued to be elevated several weeks following the procedure, consistent with a potential authentic immunomodulating effect rather than a normal inflammatory response, to be fully characterised in future studies.

In situ thermal ablation augments antitumor efficacy of adoptive T cell therapy

Purpose: The aim of this study is to investigate whether radiofrequency ablation (RFA) improves the efficacy of adoptive T cell immunotherapy in preclinical mouse cancer models.Method: Mice implanted subcutaneously (sc) with syngeneic colon adenocarcinoma or melanoma were treated with sub-curative in situ RFA (90 °C, 1 min). Trafficking of T cells to lymph nodes (LN) or tumors was quantified by homing assays and intravital microscopy (IVM) after sham procedure or RFA. Expression of trafficking molecules (CCL21 and intercellular adhesion molecule-1 [ICAM-1]) on high endothelial venules (HEV) in LN and tumor vessels was evaluated by immunofluorescence microscopy. Tumor-bearing mice were pretreated with RFA to investigate the therapeutic benefit when combined with adoptive transfer of in vitro-activated tumor-specific CD8⁺ T cells.Results: RFA increased trafficking of naïve CD8⁺ T cells to tumor-draining LN (TdLN). A corresponding increase in expression of ICAM-1 and CCL21 was detected on HEV in TdLN but not in contralateral (c)LN. IVM revealed that RFA substantially enhanced secondary firm arrest of lymphocytes selectively in HEV in TdLN. Furthermore, strong induction of ICAM-1 in tumor vessels was associated with significantly augmented trafficking of adoptively transferred in vitro-activated CD8⁺ T cells to tumors after RFA. Finally, preconditioning tumors with RFA augmented CD8⁺ T cell-mediated apoptosis of tumor targets and delayed growth of established tumors when combined with adoptive T cell transfer immunotherapy.Conclusions: These studies suggest that in addition to its role as a palliative therapeutic modality, RFA may have clinical potential as an immune-adjuvant therapy by augmenting the efficacy of adoptive T cell therapy.

Radiofrequency ablation of liver metastasis: potential impact on immune checkpoint inhibitor therapy

Percutaneous radiofrequency ablation (RFA), a generally accepted alternative therapy for patients with liver metastases, is a minimally invasive approach with a favorable safety profile and a lower rate of major complications. The use of RFA or combined RFA plus resection can produce total tumor clearance in patients with unresectable liver metastases. However, the relatively high rate of local tumor progression has prevented the widespread use of RFA. Furthermore, its efficacy is controversial because there have been no comparisons for its effect on overall survival compared with standard options such as systemic chemotherapy. Meanwhile, immunotherapy has become a major research focus for oncology based on the recent successes reported for immune checkpoint inhibitors for melanoma, non-small cell lung cancer, gastric cancer, and other cancers. Immune checkpoints negatively regulate T cell function, and inhibition prevents the blockade of the immune system by cancer cells to prevent their destruction. Unfortunately, only some patients (< 25%) respond to immuno-oncology drugs, whereas other patients acquire resistance. However, RFA can induce massive necrotic cell death which might activate immunity and the presentation of cryptic antigens to induce tumor-specific T cell response. Because RFA can induce the rapid release of large amounts of tumor antigens, it can potentially stimulate transient immune responses to much tumor antigens. Combination therapies have induced synergistic enhancement of anticancer immune response in preclinical studies, indicating great promise for the future of oncologic treatment.Key Points • Only some patients respond to immuno-oncology drugs. • RFA causes the release of large amounts of cellular debris, a source of tumor antigens that elicit immune responses against tumors. • Combination RFA for liver metastases and immune checkpoint inhibitor therapies might synergistically enhance antitumor immunity.

Enhanced antitumor efficacy through microwave ablation in combination with immune checkpoints blockade in breast cancer: A pre-clinical study in a murine model

PURPOSE

The purpose of this study was to investigate the therapeutic efficacy of the combination of microwave ablation (MWA) in combination with immune checkpoints blockade in the treatment of breast cancer using the 4T1 tumor-bearing mice model.

MATERIALS AND METHODS

We treated tumor-bearing mice with MWA, programmed cell death protein1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade (P+C), MWA plus PD-1 and CTLA-4 blockade (combination therapy), or no-treatment. Survival time was evaluated with the Kaplan-Meyer method comparing survival curves by log-rank test. On day 15 after MWA, five mice from the combination therapy group received tumor rechallenge with 4T1 or CT26 cells and the volumes of rechallenge tumor were calculated every 5 days. Immune cells were identified by immunohistochemistry and flow cytometry, and the concentrations of plasma interferon-γ (IFN-γ) were identified by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The combination therapy significantly prolonged tumor-bearing mice survival compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively) and protected most surviving mice from 4T1 tumor rechallenge (P=0.002) but not CT26 tumor rechallenge (P=0.905). Both local and systemic CD8+ T-cell responses were induced by MWA (all P<0.05) and further augmented by subsequent administration of PD-1 and CTLA-4 blockade (all P<0.05). Plasma IFN-γ concentrations were significantly elevated in the combination therapy group compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively).

CONCLUSION

MWA combined with immune checkpoints blockade could synergistically enhance antitumor efficacy with augmented specific immune responses, and the combination therapy is a promising approach to treat breast cancer.

Immunomodulation in hepatocellular cancer

Hepatocellular carcinoma (HCC) is the fastest growing malignancy in the United States in relation to mortality. HCC relies on a complex immunosuppressive network to modify the host immune system and evade destruction. Intrinsic to the liver's function and anatomy, native hepatic and immune cells produce many inhibitory cytokines that promote tolerogenicity and limit immune response. Since the introduction of sorafenib in 2008, no treatment has been able to demonstrate improved survival in patients with advanced HCC post disease progression treated with sorafenib. More recent studies have shown that sorafenib has an immunomodulatory function in addition to inhibition of multiple tyrosine kinases. Clinical trials have aimed to further enhance this immunomodulatory function with other treatments, most promisingly immune checkpoint inhibitors. Additionally, ongoing studies are using combinatorial approaches with immunomodulatory treatment and liver directed therapies such as transarterial chemoembolization (TACE), radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation. This article will review recent data describing the immunosuppressive network in HCC, recent results of immunotherapies, and combinatorial approaches to treat advanced HCC.

Case report on the role of radiofrequency-assisted spleen-preserving surgery for splenic metastasis in the era of check-point inhibitors

RATIONALE

An isolated splenic metastasis is a rare phenomenon noted in advanced stage melanoma. We report the role of radiofrequency (RF) -based splenic-preserving splenectomy in a patient with a solitary splenic metastasis from advanced stage melanoma that was managed with checkpoint inhibitors.

PATIENT CONCERNS

We report a case of a 60-year-old man who presented with multiple lung metastases and a solitary splenic metastasis with advanced stage melanoma following excision of primary from his trunk 2.3 years back.

DIAGNOSIS

Considering the diagnosis of advanced stage melanoma with multiple lung metastases and a solitary splenic metastasis, and its ongoing progressive nature. This case was discussed in the tumour board meeting.

INTERVENTIONS

A decision was made to commence treatment with immunotherapy in the form of PD-1 inhibitor (programmed cell death 1 receptor) pembrolizumab. Follow-up restaging computer tomography (CT) scan of the abdomen and chest showed a significant reduction in the lung and chest wall lesions, but the splenic lesion remained unchanged. Given the lack of response to treatment in the splenic metastasis and the significant decrease in lung metastases, the multidisciplinary team decided that a partial splenectomy combined with continued immunotherapy treatment would be appropriate as the success of immunotherapy was imminent within the splenic preservation.

OUTCOMES

The postoperative recovery was smooth and the patient was discharged from hospital on the sixth postoperative day with normal platelets and white blood cells. The histopathological analysis of the resected specimen showed a metastatic melanoma with negative margins.At 10-month follow-up after the splenic resection the patient had not experienced further tumour recurrences.

LESSONS

Spleen-preserving resection for an isolated, solitary splenic metastasis of melanoma is a feasible approach as it not only preserves the ongoing efficacy of checkpoint inhibitors by preserving the physiological T cell milieu, but the immunomodulation properties of RF can produce potentially additional therapeutic benefit.

Immunomodulation after radiofrequency ablation of locally advanced pancreatic cancer by monitoring the immune response in 10 patients

OBJECTIVE/BACKGROUND

RFA of pancreatic cancer has been demonstrated to be feasible and safe with a positive impact on survival. The aim was to investigate whether an immune reaction is activated after locally advanced pancreatic cancer (LAPC) ablation.

METHODS

Peripheral Blood samples were obtained preoperatively and on post-operative days 3-30. Evaluated parameters were: cells [CD4⁺, CD8⁺ and activated subsets, T-Reg, Monocytes, myeloid and plasmocytoid Dendritic cells (mDC and pDC)] and cytokines [Interleukin (IL)-6, Stromal-cells derived factor (SDF)-1, IL-1β, Tumour-Necrosis Factor (TNF)-α, Interferon (IFN)-γ, Vascular Endothelial Growth Factor (VEGF), chemokine (C-C motif) ligand 5 (CCL-5), Transforming-Growth Factor (TGF)-β].

RESULTS

Ten patients were enrolled. CD4⁺, CD8⁺ and TEM increased from day 3 suggesting the activation of the adaptive response. Immunosuppressive T-Reg cells were stable despite the possibility that laparotomy and heating might favour their expansion. Myeloid DCs, that present tumour-associated antigens, increased at day 30. RFA dramatically increased circulating IL-6 at day 3 but this decreased to baseline by day 30, consistent with the supposed anti-tumour effect. RFA did not significantly modulate essential chemokines, such as CCL-5 and SDF1, VEGF, TGF-β and TNF-α, that favour tumour-growth by sustaining cancer angiogenesis and fuelling tumour-associated inflammation.

CONCLUSIONS

This study provides the first evidence of RFA-based immunomodulation in LAPC. We observed a general activation of adaptive response along with a decrease of immunosuppression. Furthermore, most cells showed prolonged activation some weeks after the procedure, suggesting true immunomodulation rather than a normal inflammatory response.

Impact of cavitron ultrasonic surgical aspirator (CUSA) and bipolar radiofrequency device (Habib-4X) based hepatectomy for hepatocellular carcinoma on tumour recurrence and disease-free survival

Background

The aim of this study was to evaluate the oncological outcomes of hepatocellular carcinoma patients undergoing liver resection using cavitron ultrasonic surgical aspirator (CUSA) or radiofrequency (RF) based device Habib-4X.


Study Design

We prospectively analyzed the data of 280 patients who underwent liver resection for hepatocellular carcinoma at our institution from 2010–2012 with follow up till August 2016. The CUSA was used in the 163 patients whilst Habib-4X in 117 patients. The end points of analysis were oncological outcomes as disease recurrence, disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan–Meier method, which has been compared with all other existing literature on the survival study.

Results

Compared with CUSA the reported incidence of recurrence was significantly lower, in Habib-4X group; p < 0.01. The median DFS was significantly better in Habib-4X group than CUSA group (50.80 vs 45.87 months, p = 0.03). The median OS was better in Habib-4X group than CUSA group (60.57 vs 57.17 months, p = 0.12) though the lesser difference in OS between the groups might be explained by the use of palliative therapies as TACE, percutaneous RFA, etc. in case of recurrence.

Conclusions

RF based device Habib-4X, is safe and effective device for resection of hepatocellular carcinoma, in comparison to CUSA with better oncological outcomes, i.e., significantly lesser tumour recurrence and better DFS. This could be explained on the basis of systemic and local immunomodulatory effect involving induction of kupffer cells and effector CD-8 T cells that help in minimizing postoperative complications and bring more advantageous oncological outcomes.

Radiofrequency ablation for management of malignant biliary obstruction: a single-center experience and review of the literature

BACKGROUND

Radiofrequency ablation (RFA) causes coagulative necrosis of tissue and may be beneficial prior to biliary stenting. We report our experience using RFA for malignant biliary obstruction and review the literature.

METHODS

Retrospective analysis of all patients undergoing RFA for malignant biliary obstruction over the last two years. Success, complications and re-intervention following RFA were assessed. Controls were age, sex and disease matched who had stenting alone.

RESULTS

31 patients were included and 15 patients underwent biliary RFA prior to stenting (median age 78 years, 8 females). 14 patients had pancreatic cancer, 13 cholangiocarcinoma (6 hilar lesions) and 4 malignant disease invading the bile duct. Adverse events included acute pancreatitis (n = 2) and bacteremia in (n = 1). Median duration of intervention free survival was 220 days in the RFA group compared to 106.5 days in controls (hazard ratio 2.4, 95% CI 1.1 - 5.3, p = 0.025). Multivariable Cox proportional hazard analysis showed survival was associated with RFA (hazard ratio 2.55, 95% CI 1.09-5.96, p = 0.026) but not age, site or type of malignancy.

CONCLUSION

Biliary RFA is a technically feasible with a low adverse event rate and is associated with increased survival. Multi-centre randomized controlled trials are required.

Tumor-induced MDSC act via remote control to inhibit L-selectin-dependent adaptive immunity in lymph nodes

Myeloid-derived suppressor cells (MDSC) contribute to an immunosuppressive network that drives cancer escape by disabling T cell adaptive immunity. The prevailing view is that MDSC-mediated immunosuppression is restricted to tissues where MDSC co-mingle with T cells. Here we show that splenic or, unexpectedly, blood-borne MDSC execute far-reaching immune suppression by reducing expression of the L-selectin lymph node (LN) homing receptor on naïve T and B cells. MDSC-induced L-selectin loss occurs through a contact-dependent, post-transcriptional mechanism that is independent of the major L-selectin sheddase, ADAM17, but results in significant elevation of circulating L-selectin in tumor-bearing mice. Even moderate deficits in L-selectin expression disrupt T cell trafficking to distant LN. Furthermore, T cells preconditioned by MDSC have diminished responses to subsequent antigen exposure, which in conjunction with reduced trafficking, severely restricts antigen-driven expansion in widely-dispersed LN. These results establish novel mechanisms for MDSC-mediated immunosuppression that have unanticipated implications for systemic cancer immunity.

DOI:http://dx.doi.org/10.7554/eLife.17375.001

Thermal and mechanical high-intensity focused ultrasound: perspectives on tumor ablation, immune effects and combination strategies

Tumor ablation technologies, such as radiofrequency-, cryo- or high-intensity focused ultrasound (HIFU) ablation will destroy tumor tissue in a minimally invasive manner. Ablation generates large volumes of tumor debris in situ, releasing multiple bio-molecules like tumor antigens and damage-associated molecular patterns. To initiate an adaptive antitumor immune response, antigen-presenting cells need to take up tumor antigens and, following activation, present them to immune effector cells. The impact of the type of tumor ablation on the precise nature, availability and suitability of the tumor debris for immune response induction, however, is poorly understood. In this review, we focus on immune effects after HIFU-mediated ablation and compare these to findings using other ablation technologies. HIFU can be used both for thermal and mechanical destruction of tissue, inducing coagulative necrosis or subcellular fragmentation, respectively. Preclinical and clinical results of HIFU tumor ablation show increased infiltration and activation of CD4⁺ and CD8⁺ T cells. As previously observed for other types of tumor ablation technologies, however, this ablation-induced enhanced infiltration alone appears insufficient to generate consistent protective antitumor immunity. Therapies combining ablation with immune stimulation are therefore expected to be key to boost HIFU-induced immune effects and to achieve systemic, long-lasting, antitumor immunity.

Pre-resectional Radiofrequency Ablation as a Neoadjuvant in situ Tumor Vaccine

A lack of effective immune response against cancer is one of the major risk factors for developing local recurrence and distant metastases after curative resectional surgery. Prior studies revealed that systemic antitumor immunity is elicited by radiofrequency ablation (RFA) of tumor lesions, which is mainly considered a palliative procedure for unresectable tumors or for inoperable patients. Recently, we discovered an oncological benefit that depends on the adaptive arm of the antitumor immune response when RFA is performed in a neoadjuvant setting prior to surgical resection in preclinical murine models.