Serum cytokine levels in response to hepatic cryoablation

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.

Distinct immunoreactions after a primary tumor microwave ablation using different heating parameters in a VX2 tumor model

BACKGROUND

Thermal ablation of solid tumors in situ can activate the immune system and produce a specific immune response against the tumor. Microwave ablation (MWA) with different parameters can ablate tumors with similar sizes and cause different local inflammatory effects. Our aim was to determine the immunological effects induced by different energy modes of MWA for a primary tumor.

METHODS

Seventy rabbits with VX2 tumors that were implanted subcutaneously underneath the right second nipple were treated with high-power MWA (40 W for 1 min), low-power MWA (20 W for 2 min), or surgical resection or were left without treatment (control). Survival time was evaluated by log-rank test. On day 14 after ablation, immunohistochemistry and flow cytometry were used to evaluate the T-cell immune responses. In addition, the cytokine patterns were identified by enzyme-linked immunosorbent assay.

RESULTS

Tumor eradication was achieved completely in the MWA groups, as proven by nicotinamide adenine dinucleotide diaphorase staining. Compared with the three treatment groups, the control group had a significantly higher number of pulmonary metastases and worse survival; however, no significant difference was observed among the three treatment groups. More intra-tumoral and systemic CD4+ and CD8+ T-cells were induced in the MWA groups than in the control group. Compared with operation, MWA induced more systemic CD4+ T-cells. More intra-tumoral CD4+ and CD8+ T-cells and systemic CD4+ T-cells were induced by high-power MWA than by low-power MWA. Moreover, MWA increased the interleukin 2 (IL2) and IL12 levels and decreased the IL4, IL6, and IL10 levels. Importantly, the serum IL12 level was significantly higher after high-power MWA than after low-power MWA.

CONCLUSION

High-power MWA enhanced the type 1 T helper immune response and may be selected for the treatment of solid tumors. Future studies are needed to confirm our results.

Local treatment of liver metastasis in a patient with advanced malignant melanoma: A case report

Melanoma is a fatal malignant tumor with a high rate of metastasis. Liver metastasis of melanoma is always associated with insensitivity to immunotherapy and a poor prognosis. However, the combination of cryoablation, which is believed to stimulate the antitumor immune response in the body, with immunotherapy can improve the therapeutic response to this condition. Herein, we present the case of a 79-year-old woman with BRAF (B-Raf proto-oncogene) wild-type melanoma who later developed liver metastasis. The patient received intravenous antiprogrammed cell death 1 antibody, which showed poor efficacy, and subsequent treatment with immunotherapy combined with cryoablation yielded a partial response. However, after the second cryoablation, the patient refused further treatment due to a fear of bleeding. Therefore, only immunotherapy was provided, which resulted in disease progression. This report demonstrates the need to consider immunotherapy plus cryoablation for the treatment of liver metastases in patients with BRAF wild-type melanoma.

Inducing the Abscopal Effect in Liver Cancer Treatment: The Impact of Microwave Ablation Power Levels and PD-1 Antibody Therapy

Microwave ablation (MWA) is an effective treatment for liver cancer (LC), but its impact on distant tumors remains to be fully elucidated. This study investigated the abscopal effects triggered by MWA treatment of LC, at different power levels and with or without combined immune checkpoint inhibition (ICI). We established a mouse model with bilateral subcutaneous LC and applied MWA of varied power levels to ablate the right-sided tumor, with or without immunotherapy. Left-sided tumor growth was monitored to assess the abscopal effect. Immune cell infiltration and distant tumor neovascularization were quantified via immunohistochemistry, revealing insights into the tumor microenvironment and neovascularization status. Th1- and Th2-type cytokine concentrations in peripheral blood were measured using ELISA to evaluate systemic immunological changes. It was found that MWA alone, especially at lower power, promoted distant tumor growth. On the contrary, combining high-power MWA with anti-programmed death (PD)-1 therapy promoted CD8+ T-cell infiltration, reduced regulatory T-cell infiltration, upregulated a Th1-type cytokine (TNF-α) in peripheral blood, and inhibited distant tumor growth. In summary, combining high-power MWA with ICI significantly enhances systemic antitumor immune responses and activates the abscopal effect, offering a facile and robust strategy for improving treatment outcomes.

Combination Therapy of Immune Checkpoint Inhibitors with Locoregional Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is estimated to be the fourth leading cause of cancer-related deaths globally, and its overall prognosis is dismal because most cases are diagnosed at a late stage and are unamenable to curative treatment. The emergence of immune checkpoint inhibitors (ICIs) has dramatically improved the therapeutic efficacy for advanced hepatocellular carcinoma; however, their response rates remain unsatisfactory, partly because >50% of HCC exhibit an ICI-nonresponsive tumor microenvironment characterized by a paucity of cytotoxic T cells (immune-cold), as well as difficulty in their infiltration into tumor sites (immune excluded). To overcome this limitation, combination therapies with locoregional therapies, including ablation, transarterial embolization, and radiotherapy, which are usually used for early stage HCCs, have been actively explored to enhance ICI efficacy by promoting the release of tumor-associated antigens and cytokines, and eventually accelerating the so-called cancer-immunity cycle. Various combination therapies have been investigated in early- to late-phase clinical trials, and some have shown promising results. This comprehensive article provides an overview of the immune landscape for HCC to understand ICI efficacy and its limitations and, subsequently, reviews the status of combinatorial therapies of ICIs with locoregional therapy for HCC.

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.

Percutaneous Ablation-Induced Immunomodulation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths worldwide and its incidence is rising. Percutaneous locoregional therapies, such as radiofrequency ablation and microwave ablation, are widely used as curative treatment options for patients with small HCC, but their effectiveness remains restricted because of the associated high rate of recurrence, occurring in about 70% of patients at five years. These thermal ablation techniques have the particularity to induce immunomodulation by destroying tumours, although this is not sufficient to raise an effective antitumour immune response. Ablative therapies combined with immunotherapies could act synergistically to enhance antitumour immunity. This review aims to understand the different immune changes triggered by radiofrequency ablation and microwave ablation as well as the interest in using immunotherapies in combination with thermal ablation techniques as a tool for complementary immunomodulation.

Cryoablation and Immunotherapy: An Enthralling Synergy to Confront the Tumors

Treatment of solid tumors by ablation techniques has gained momentum in the recent years due to their technical simplicity and reduced morbidity as juxtaposed to surgery. Cryoablation is one of such techniques, known for its uniqueness to destroy the tumors by freezing to lethal temperatures. Freezing the tumor locally and allowing it to remain in situ unleashes an array of tumor antigens to be exposed to the immune system, paving the way for the generation of anti-tumor immune responses. However, the immune responses triggered in most cases are insufficient to eradicate the tumors with systemic spread. Therefore, combination of cryoablation and immunotherapy is a new treatment strategy currently being evaluated for its efficacy, notably in patients with metastatic disease. This article examines the mechanistic fabric of cryoablation for the generation of an effective immune response against the tumors, and various possibilities of its combination with different immunotherapies that are capable of inducing exceptional therapeutic responses. The combinatorial treatment avenues discussed in this article if explored in sufficient profundity, could reach the pinnacle of future cancer medicine.

Application of cryoablation to treat peritoneal carcinomatosis from gastric cancer in a rabbit model

OBJECTIVES

Peritoneal carcinomatosis is one of the causes of death in patients with advanced gastric cancer. We assumed that cryoablation could be applied as adjuvant therapy to control peritoneal carcinomatosis from gastric cancer.

METHODS

We investigated the feasibility of cryoablation technique in rabbit model using a novel cryoablation balloon probe. The cryozones were harvested 7 days after cryoablation for histological evaluation. The levels of cytokines in the peripheral blood of rabbits were also detected.

RESULTS

The results demonstrated that cryoablation could be applied in a rabbit model of peritoneal carcinomatosis from gastric cancer. Seven days after cryoablation, necrotic tumor cells could be seen the cryozones. Higher level of IFN-γ was observed. The level of IL-10 was decreased after treatment.

CONCLUSIONS

The findings provided the experimental basis for the future application of cryoablation in patients.

A Phase II Study of Tumor Ablation in Patients with Metastatic Sarcoma Stable on Chemotherapy

Lessons Learned.

Ablation therapy appears to be a reasonably safe and effective approach to obtain a significant treatment‐free interval for a subset of patients with limited sites of metastatic disease for which systemic control can be obtained with six cycles of chemotherapy.

Background.

Metastatic sarcoma often becomes resistant to treatment by chemotherapy. There is sometimes prolonged stable disease from active chemotherapy that provides a window of opportunity for an intervention to prolong disease‐free survival.

Materials and Methods.

We performed a phase II study in patients with metastatic sarcoma who had been stable on six cycles of chemotherapy who then received ablation therapy to their residual disease. Histologies captured in this study included leiomyosarcoma, malignant peripheral nerve sheath tumor, pleiomorphic rhabdomyosarcoma, and myxoid liposarcoma. Sites ablated included lung metastases and retroperitoneal metastatic deposits. In this study, up to three lesions were ablated in any given interventional radiology session. After ablation, patients were not treated with any further therapy but were followed by surveillance imaging to determine progression‐free rate (PFR).

Results.

Although terminated early because of slow accrual, this study demonstrated a 3‐month PFR of 75% for this cohort of eight patients treated with ablation performed after completion of six cycles of chemotherapy with stable disease. Median progression‐free survival (PFS) was 19.74 months, and the median overall survival (OS) was not reached.

Conclusion.

Our data are the first prospective study to suggest that ablation therapy in selected patients who are stable on chemotherapy can provide a significant progression‐free interval off therapy and warrants further study in a randomized trial.

A histological examination of spinal reconstruction using a frozen bone autograft

Our aim was to compare the process of bone formation after reconstruction of the vertebral body using a titanium cage with either a liquid nitrogen-treated (frozen) bone autograft or non-treated fresh bone autograft. Twelve canine beagles underwent anterior reconstruction of the 5^th lumbar vertebrae using a titanium cage and bone autograft. Bone formation was compared across four experimental groups: fresh bone autograft groups, with animals sacrificed at either 8 or 16 weeks post-reconstruction, and liquid nitrogen-treated (frozen) bone autograft groups, with animals again sacrificed at either 8 or 16 weeks post-reconstruction. Bone formation was evaluated histologically by calculating the proportion of ‘reaction’ and ‘mature bone’ regions at the ends of the cage, its center, and ventral/dorsal sides. The reaction region contained osteocytes with a nucleus and osteoblasts accumulated on the surface of an osteoid, while a laminar structure was visible for mature bone regions. For fresh bone autografts, the reaction and mature bone regions significantly increased from 8 to 16 weeks post-reconstruction. By comparison, for frozen autografts, the reaction bone region did not significantly increase from 8 to 16 weeks post-reconstruction, while the mature bone region did increase over this time period. The proportion of reaction bone was higher at the ends and dorsal side of the cage at 8 weeks, for both graft types, with greater bone formation at the center of the cage at 16 weeks only for the fresh bone autograft. Therefore, bone formation in the anterior spinal reconstruction site tended to be delayed when using a frozen bone autograft compared to a fresh bone autograft. The bone formation process, however, was similar for both groups, beginning at the ends and dorsal side of the cage adjacent to the surrounding vertebral bone.

Optimized magnitude of cryosurgery facilitating anti-tumor immunoreaction in a mouse model of Lewis lung cancer

BACKGROUND

Cryosurgery has reemerged as a less invasive local treatment with possible immune-regulatory effects. However, the optimal magnitude of cryosurgery for achieving immune-regulatory responses at abscopal tumor sites remains unclear. We aimed to investigate appropriate magnitude of cryosurgery for this goal using a mouse model.

METHODS

C57BL/6J mice were inoculated with Lewis lung carcinoma cells or B16 melanoma cells in bilateral flanks. The left-sided tumor was cryoablated with repeated freeze/thaw cycles either once, twice, or thrice. The peritumoral injections of LPS were performed. Abscopal tumor volumes were measured, immunohistochemistry was performed for CD4, CD8, Foxp3, and Ki-67, and proinflammatory cytokines were measured in lavage fluid of cryoablated tumor.

RESULTS

The growth rate of the abscopal tumor was slowest in the Cryosurgery ×2 group among the five experimental groups. The proportions of CD4(+) T cells and CD8(+) T cells in the abscopal tumor were also significantly higher in the Cryosurgery ×2 group. The levels of IL-1β, IL-2, IL-6, IL-12β, IFN-γ, and TNF-α in the peritumoral lavage fluid in Cryosurgery ×2 + LPS group were significantly increased compared with the other groups.

CONCLUSIONS

This study suggested that achievement of approximately 73 % damaged area in the cryoablated tumor by two cycles of cryosurgery generates the most favorable immune-regulatory response for abscopal tumors via activation of anti-tumor immune cells as well as increased secretion of proinflammatory cytokines.

Thermal Ablative Therapies and Immune Checkpoint Modulation: Can Locoregional Approaches Effect a Systemic Response?

Percutaneous image-guided ablation is an increasingly common treatment for a multitude of solid organ malignancies. While historically these techniques have been restricted to the management of small, unresectable tumors, there is an expanding appreciation for the systemic effects these locoregional interventions can cause. In this review, we summarize the mechanisms of action for the most common thermal ablation modalities and highlight the key advances in knowledge regarding the interactions between thermal ablation and the immune system.

Clinically feasible approaches to potentiating cancer cell-based immunotherapies

The immune system exerts both tumor-destructive and tumor-protective functions. Mature dendritic cells (DCs), classically activated macrophages (M1), granulocytes, B lymphocytes, aβ and ɣδ T lymphocytes, natural killer T (NKT) cells, and natural killer (NK) cells may be implicated in antitumor immunoprotection. Conversely, tolerogenic DCs, alternatively activated macrophages (M2), myeloid-derived suppressor cells (MDSCs), and regulatory T (Tregs) and B cells (Bregs) are capable of suppressing antitumor immune responses. Anti-cancer vaccination is a useful strategy to elicit antitumor immune responses, while overcoming immunosuppressive mechanisms. Whole tumor cells or lysates derived thereof hold more promise as cancer vaccines than individual tumor-associated antigens (TAAs), because vaccinal cells can elicit immune responses to multiple TAAs. Cancer cell-based vaccines can be autologous, allogeneic or xenogeneic. Clinical use of xenogeneic vaccines is advantageous in that they can be most effective in breaking the preexisting immune tolerance to TAAs. To potentiate immunotherapy, vaccinations can be combined with other modalities that target different immune pathways. These modalities include 1) genetic or chemical modification of cell-based vaccines; 2) cross-priming TAAs to T cells by engaging dendritic cells; 3) T-cell adoptive therapy; 4) stimulation of cytotoxic inflammation by non-specific immunomodulators, toll-like receptor (TLR) agonists, cytokines, chemokines or hormones; 5) reduction of immunosuppression and/or stimulation of antitumor effector cells using antibodies, small molecules; and 6) various cytoreductive modalities. The authors envisage that combined immunotherapeutic strategies will allow for substantial improvements in clinical outcomes in the near future.

Cryoablation and Meriva have strong therapeutic effect on triple-negative breast cancer

Interleukin-6, a cytokine produced particularly by triple-negative breast cancers, strongly inhibits T cell responses in the tumor microenvironment. Here we tested cryoablation combined with Meriva (a lecithin delivery system of curcumin with improved bioavailability) in mice with metastatic breast cancer (4T1). Cryoablation involves killing of tumor cells through freezing and thawing, resulting in recruitment of tumor-specific T cells, while curcumin stimulates T cells through the reduction of IL-6 in the TME. Cryoablation plus Meriva accumulated and activated CD8⁺ T cells to multiple tumor-associated antigens such as Mage-b and Survivin (both expressed by 4T1 tumors). This correlated with a nearly complete reduction of 4T1 primary tumors and lung metastases while little effect was observed from saline or Meriva alone (28 d after tumor cell injection). The survival rate in the group of cryoablation plus Meriva was significantly improved compared to all control groups. Using a less aggressive 4T1 model expressing luciferase (4T1.2luc3), we demonstrated that all mice receiving saline or Meriva developed metastases in the lungs and a primary tumor (38 d after tumor cell injection; and died soon after that), but not the mice receiving cryoablation or cryoablation plus Meriva. However, on day 58 the mice receiving cryoablation developed 4T1.2luc3 metastases in the lungs, while mice receiving cryoablation plus Meriva were free of metastases. These results strongly suggest that cryoablation delayed the development of lung metastases on the short-term, but Meriva administered after cryoablation was significantly better in delaying the development of lung metastases and survival on the long-term.

Double-blinded, randomized phase II study using embolization with or without granulocyte-macrophage colony-stimulating factor in uveal melanoma with hepatic metastases

PURPOSE

To investigate the effects of immunoembolization with granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with uveal melanoma (UM) with liver-only metastasis.

MATERIALS AND METHODS

In this double-blind phase II clinical trial, patients were randomized to undergo immunoembolization or bland embolization (BE). Lobar treatment was performed with GM-CSF or normal saline solution mixed with ethiodized oil followed by embolization with gelatin sponge emulsified with iodinated contrast medium. Fifty-two patients (immunoembolization, n = 25; BE, n = 27) were enrolled. Response was assessed after every two treatments. The primary endpoint was overall response rate (ORR) of liver metastases. Progression-free survival (PFS), overall survival (OS), and immunologic responses were secondary endpoints.

RESULTS

There were five partial responses in the immunoembolization group (ORR, 21.2%; 90% confidence interval [CI], 10.3%-30.5%) and three in the BE group (ORR, 16.7%; 90% CI, 6.3%-26.9%). Stable disease was seen in 12 patients in the immunoembolization group and 19 in the BE group. OS times were 21.5 months (95% CI, 18.5-24.8 mo) with immunoembolization and 17.2 months (95% CI, 11.9-22.4 mo) with BE. The degree of proinflammatory cytokine production was more robust after immunoembolization and correlated with time to "systemic" extrahepatic progression. In the immunoembolization group, interleukin (IL)-6 levels at 1 hour (P = .001) and IL-8 levels at 18 hours after the procedure (P < .001) were significant predictors of longer systemic PFS. Moreover, a dose-response pattern was evident between posttreatment serum cytokine concentrations and systemic PFS.

CONCLUSIONS

Immunoembolization induced more robust inflammatory responses, which correlated with the delayed progression of extrahepatic systemic metastases.

Tumor-specific immunity induced by cryoablation in a murine renal cell carcinoma model

Purpose

To evaluate tumor-specific immunity and define the mechanisms involved in the cryoimmunologic response, we compared the tumor control efficacy and immunologic responses of cryoablation with those of surgical excision in a tumor rechallenge model.

Materials and Methods

Sixty BALB/c mice with RENCA tumors that were generated in the left flank area underwent cryoablation or radical excision. The mice successfully treated were rechallenged with RENCA or an undifferentiated colon carcinoma cell line, CT26, in the contralateral right flank area. The recurrence rate after tumor rechallenge in each group was then observed. To assess the immunologic response of each treatment modality, fluorescent-activated cell sorting (FACS) analysis and a cytotoxicity assay using ⁵¹Cr release were performed.

Results

After reinoculation of the RENCA cells, the rate of tumor growth was significantly higher in the surgical excision group than in the cryoablation group (94.4% vs. 11.1%, p=0.001). In the cryoablation group, the tumor growth rate was significantly increased after rechallenge of CT26 cells compared with RENCA (94.1% vs. 11.1%, p=0.001). The cryoablation group showed an elevated CD3, CD4, CD8 T, and natural killer cell count in the FACS analysis and also showed significantly increased cytotoxicity in the ⁵¹Cr release assay compared with the excision group.

Conclusions

These results showed that cryoablation, compared to surgical resection, was more effective in preventing tumor growth after rechallenge with RENCA cells and that this response was tumor-specific, because the CT26 cells did not have the same effect.

Advances in clinical application of cryoablation therapy for hepatocellular carcinoma and metastatic liver tumor

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Although surgical resection and liver transplantation are the curative treatments, many of HCC patients do not qualify for these curative therapies at the presentation. Thus, ablation therapies are currently important modalities in HCC treatment. Among currently available ablation therapies, cryoablation (ie, cryotherapy) is a novel local therapeutic modality. However, cryoablation has not been widely used as one of ablation therapies for HCC, because of historical concerns about risk of bleeding when cryotherapy is delivered by early generation of the argon-helium device. Nevertheless, with technological advances and increased clinical experience in the past decade, clinical application of cryoablation for HCC management has significantly increased. Accumulating data have demonstrated that cryoablation is highly effective in local tumor control with well-acceptable safety profile, and the overall survival is comparable with that of radiofrequency ablation in patients with tumors <5 cm. Compared with radiofrequency ablation and other thermal-based modalities, cryoablation has several advantages, such as the ability to produce larger and precise zones of ablation. This article systemically reviews the advances in clinical application of cryoablation therapy for HCC, including the related mechanisms and technology, clinical indications, efficacy and safety profiles, and future research directions.

Systemic antitumor immune response following reconstruction using frozen autografts for total en bloc spondylectomy

BACKGROUND CONTEXT

Total en bloc spondylectomy (TES) is a surgery designed to achieve complete resection of a malignant spinal tumor, such as spinal metastasis. Although this procedure decreases the rate of local recurrence, it is questionable whether local control prolongs a patient's survival. In cryosurgery, antitumor immunity is activated after percutaneous cryoablation of tumors. We applied this tumor-induced cryoimmunology to TES surgery and developed a "second-generation TES" that brings about TES enhancing antitumor immunity to prolong a patient's survival.

PURPOSE

To present a second-generation TES applied tumor-induced cryoimmunology and assess the immunity-enhancing effect after implementing this surgery.

STUDY DESIGN

This is a retrospective review of prospectively collected data.

PATIENT SAMPLE

The sample consisted of 65 consecutive patients who underwent second-generation TES.

OUTCOME MEASURES

Interferon gamma (IFN-γ) and interleukin-12 (IL-12) before surgery and at both 1 and 3 months after surgery was used to assess the immunity-enhancing effect.

METHODS

In second-generation TES, instead of harvesting autograft from the ilium or fibula, the resected lamina and vertebral body from TES are frozen using liquid nitrogen and used as grafted bone for spinal reconstruction. In the most recent 33 of the 65 cases, in addition to the TES procedure, a small amount of the tumor tissue from the resected tumor-bearing vertebra was also placed into liquid nitrogen. This small amount of tumor tissue was then implanted subcutaneously on one side of the axilla at the end of the TES surgery. In 60 of 65 cases, measurement of IFN-γ and IL-12 was performed.

RESULTS

IFN-γ increased after surgery in 45 (75%) of 60 cases. The mean IFN-γ relative concentrations at both 1 and 3 months after surgery, as compared with before surgery, were significantly higher (284%±596% and 275%±354%: p<.05). IL-12 increased after surgery in 44 (73.3%) of 60 cases. The mean IL-12 relative concentrations at both 1 and 3 months after surgery, as compared with before surgery, were significantly higher (277%±385% and 486%±1032%: p>.05 and p<.01) at 3 months. At final follow-up, 13 of the 65 patients died due to progression of metastases (mean 12.6 months after TES), 15 remained free from disease, and 36 patients were alive with disease.

CONCLUSIONS

The second-generation TES using frozen tumor-bearing autograft inside a cage affords three benefits: (1) no pain at the bone harvest site, (2) shortening of operation time, and (3) decrease of blood loss. Moreover, our results show that second-generation TES provides not only a local radical cure but also a systemic immunological enhancement.

Saikosaponin-d affects the differentiation, maturation and function of monocyte-derived dendritic cells

Saikosaponin-d (Ssd) is a triterpenoid saponin derived from Bupleurum falcatum L., which has been shown to exhibit a variety of pharmacological properties, including anti-inflammatory, antibacterial and antiviral properties. The aim of the present study was to investigate the effect of Ssd on the differentiation, maturation and function of human monocyte-derived dendritic cells (DCs) isolated from condylomata acuminata patients. The results of the present study demonstrated that Ssd reduced the differentiation of DCs, as evidenced by decreased expression levels of cluster of differentiation (CD)1a, CD80 and CD86 molecules and increased CD14 expression. Expression levels of the mannose receptor and CD32 were also significantly elevated, which was associated with enhanced fluorescein isothiocyanate-dextran endocytic activity. Furthermore, Ssd treatment promoted DC maturation by increasing the expression levels of CD40, CD83, CD80 and CD86. In addition, the function of mature DCs, including the secretion of IL-12 and the stimulation of lymphocyte proliferation, was significantly increased following Ssd administration. In conclusion, the present study indicated that Ssd exhibited immunomodulatory effects and may be a novel potent chemopreventive drug candidate for the treatment of condylomata acuminata.

Comparison of percutaneous cryoablation with microwave ablation in a porcine liver model

We compared imaging and pathological changes between argon-helium cryosurgical (AH) and microwave (MW) ablation in a porcine liver model. Immediately after ablation, computed tomography (CT) imaging showed that the area affected by MW ablation was considerably greater than that affected by AH ablation; moreover, the surface area of necrotic tissue was considerably greater in the AH group, whereas the depth of the necrotic area was similar. Seven days after ablation, the affected area had not changed much in the AH group, but it had significantly increased in the MW group; similarly, the surface and depth of the necrotic areas had not changed much in the AH group, but they had increased significantly in the MW group. The pathological findings showed similar definitive areas for both groups at both time points. The findings indicated that long time after both therapies, complete tissue necrosis can be achieved, but the extent and depth of necrosis differ: necrosis foci after AH ablation could be predicted by ice ball under CT image, and necrosis foci after MW ablation will increase obviously. MW ablation might therefore be suitable for tumors with a larger volume and simple anatomical structures, and AH ablation might be suitable for tumors with complex anatomical structures or those located near important organs. These two methods could therefore be used in combination in clinical settings, but details of the procedure need to be studied.

Clinical outcome, proteome kinetics and angiogenic factors in serum after thermoablation of colorectal liver metastases

Background

Thermoablation is used to treat patients with unresectable colorectal liver metastases (CRLM). We analyze clinical outcome, proteome kinetics and angiogenic markers in patients treated by cryosurgical ablation (CSA) or radiofrequency ablation (RFA).

Methods

205 patients underwent CSA (n = 20), RFA (n = 22), partial hepatectomy (PH, n = 134) or were found truly unresectable (n = 29). Clinical outcome, proteome transitions and angiogenic response in serum were analyzed at various time points after ablation.

Result

Median overall survival in CSA patients (17.6 months) was worse (p < 0.0001) when compared to RFA treated patients (51.7 months) and patients after PH (43.4 months). The complication rate was higher in the CSA group (50%) as compared to the RFA group (22%). Proteomics analyses showed consistently more changes in serum protein abundance with CSA compared to RFA. In the first four days after ablation a pro-angiogenic serum response occurred.

Conclusions

RFA of CRLM is superior to CSA with a median survival which equals survival in patients after PH. Proteomics analyses suggests a more aggravated serum response to CSA compared to RFA. Thermoablation is associated with changes in serum levels of angiogenic factors favouring a pro-angiogenic environment, but without differences between RFA and CSA.

Increase of IL-12 following reconstruction for total en bloc spondylectomy using frozen autografts treated with liquid nitrogen

Background

Total en bloc spondylectomy (TES) is a surgery designed to achieve complete resection of a malignant spinal tumor such as spinal metastasis. Although this procedure decreases the rate of local recurrence, it is questionable whether local control prolongs patient’s survival. We developed a “second-generation TES” that brings about TES enhancing antitumor immunity to prolong patient’s survival. Our purpose is to present a second-generation TES applied tumor-induced cryoimmunology and assess the immunity-enhancing effect after implementing this surgery.

Methods

We performed a retrospective review of prospectively collected data in second-generation TES as carried out in 56 cases. In second-generation TES, instead of harvesting autograft from the ilium or fibula, the resected lamina and vertebral body from TES are frozen using liquid nitrogen and used as grafted bone for spinal reconstruction. In recent 26 of the 56 cases, in addition to the TES procedure, a small amount of the tumor tissue from the resected tumor-bearing vertebra was also placed into liquid nitrogen. This small amount of tumor tissue was then implanted subcutaneously on one side of the axilla. In 52 of 56 cases, measurement of interleukin 12 (IL-12) was performed before surgery and at both 1 and 3 months after surgery.

Results

IL-12 increased after TES surgery in 38 of 52 cases (73.1%). The mean IL-12 relative concentrations at both 1 and 3 months after surgery, as compared to before surgery, were significantly higher (121±89 and 149±111%: P<0.05 and P<0.01).

Conclusions

Our results show that second-generation TES may provide not only a local radical cure but also a systemic immunological enhancement. Further prolonged survival in patients with a malignant spinal tumor is promising by second-generation TES.

Outcomes of ultrasound-guided percutaneous argon-helium cryoablation of hepatocellular carcinoma

PURPOSE

To evaluate the efficacy and safety of ultrasound (US)-guided percutaneous argon-helium cryoablation for hepatocellular carcinoma (HCC) and determine appropriate indications.

METHODS

We reviewed outcomes of 300 HCC patients who underwent US-guided percutaneous cryoablation.

RESULTS

Overall, 223 tumors (mean diameter 7.2 ± 2.8 cm) in 165 patients were incompletely ablated, while 185 tumors (mean diameter 5.6 ± 0.8 cm, P = 0.0001 vs. incomplete ablation) in 135 patients were completely ablated. Nineteen patients (6.3%) developed serious complications while in hospital, including cryoshock syndrome in six patients, hepatic bleeding in five, stress-induced gastric bleeding in four, liver abscess in one and intestinal fistulas in one. Two patients died because of liver failure. The median follow-up was 36.7 months (range 6-63 months). The local tumor recurrence rate was 31%, and was related to tumor size (P = 0.029) and tumor location (P = 0.037). The mean survival duration of patients with early, intermediate and advanced HCC (Barcelona Clinic Liver Cancer staging system) was 45.7 ± 3.8, 28.4 ± 1.2 and 17.7 ± 0.6 months, respectively.

CONCLUSIONS

US-guided percutaneous cryoablation is a relatively safe and effective therapy for selected HCC patients.

High intratumoral metastasis-associated in colon cancer-1 expression predicts poor outcomes of cryoablation therapy for advanced hepatocellular carcinoma

BACKGROUND

Cryoablation is one of the local therapies for hepatocellular carcinoma (HCC), but its safety and effect has not been studied in patients with Child class A or B and Barcelona Clinic Liver Cancer (BCLC) stage C HCC. Metastasis-associated in colon cancer-1 (MACC1) overexpression has been associated with poor prognosis of HCC, but its predictive value to post-cryoablation outcomes remains unknown in patients with BCLC stage C HCC.

METHODS

This study assessed the safety and outcomes of cryoablation measured by time to progression (TTP) and overall survival (OS), and predictive value of MACC1 mRNA and protein overexpression in tumorous tissue to post-cryoablation outcomes in 120 advanced HCC patients with child-pugh class A or B by quantitative polymerase chain reaction and immunohistochemical staining. The potenial correlation of MACC1 and c-Met expression to tumor cell proliferation and apoptosis was also analyzed.

RESULTS

The cryoablation in patients with advanced unresectable HCC resulted in a median TTP and OS of 5.5 (4.2- 6.7) months and 10.5 (9.0-12.0) months, respectively and no significant complications, comparable to the historical report for RFA therapy. The MACC1 mRNA and nuclear protein expression was significantly increased in tumorous tissues in these patients than that in normal liver tissue controls. Higher expression of MACC1 mRNA and nuclear protein in tumorous tissues in these patients was associated with shorter post cryoablation median TTP and OS than that with lower MACC1 expression.

CONCLUSIONS

Cryoablation is a safe and effective therapeutic option for patients with advanced HCC and Child-pugh class A or B cirrhosis; and a higher intratumoral expression of MACC1 or nuclear translocation predicts poor outcomes of cryotherapy in these patients.

Tumour seeding after percutaneous cryoablation for hepatocellular carcinoma

AIM: To assess the rate and risk factors for tumour seeding in a large cohort of patients.

METHODS: Over an 8-year period, 1436 hepatocellular carcinoma (HCC) patients with 2423 tumour nodules underwent 3015 image-guided percutaneous cryoablation sessions [1215 guided by ultrasonography and 221 by spiral computed tomography (CT)]. Follow-up CT or magnetic resonance imaging was performed every 3 mo. The detailed clinical data were recorded to analyse the risk factors for seeding.

RESULTS: The median follow-up time was 18 (range 1-90) mo. Seeding was detected in 11 patients (0.76%) at 1-24 (median 6.0) mo after cryoablation. Seeding occurred along the needle tract in 10 patients and at a distant location in 1 patient. Seeded tumours usually showed similar imaging and histopathological features to the primary HCCs. Univariate analyses identified subcapsular tumour location and direct subcapsular needle insertion as risk factors for seeding. Multivariate analysis showed that only direct subcapsular needle insertion was an independent risk factor for seeding (P = 0.017; odds ratio 2.57; 95%CI: 1.47-3.65). Seeding after cryoablation occurred earlier in patients with poorly differentiated HCC than those with well or moderately differentiated HCC [1.33 ± 0.577 mo vs 11.12 ± 6.896 mo; P = 0.042; 95%CI: (-19.115)-(-0.468)].

CONCLUSION: The risk of seeding after cryoablation for HCC is small. Direct puncture of subcapsular tumours should be avoided to minimise seeding.

Recent progress in understanding the effect of interventional therapy for hepatic carcinoma on immune function

Liver cancer is a common highly malignant tumor in China, with a high rate of recurrence and metastasis. The body's immune function is closely related with the occurrence and development of liver cancer, and low immunological function is an important reason why hepatic carcinoma is hard to cure and tend to recur and metastasize. At present, surgery-based comprehensive therapy plays a dominant role in the treatment of hepatic carcinoma; however, the majority of patients had lost their opportunities for surgical treatment when a definitive diagnosis was established. Interventional therapy is regarded as the first choice of nonsurgical treatment for hepatic carcinoma. Interventional therapy can not only result in coagulative tumor necrosis but also promote apoptosis of tumor cells. The body's immune function can be enhanced to improve the anti-tumor ability by interventional therapy, especially the cellular immune function. As a result, the metastasis and recurrence of hepatic carcinoma may be inhibited. The purpose of this article is to review the progress in understanding the effect of interventional therapy for hepatic carcinoma on immune function.

Cryotherapy is associated with improved clinical outcomes of Sorafenib therapy for advanced hepatocellular carcinoma

We assessed the safety and efficacy of sorafenib with cryotherapy (cryoRx) in advanced hepatocellular carcinoma (HCC). One hundred four HCC patients were enrolled, who met the following criteria: (i) Barcelona Clinic Liver Cancer stage C; (ii) HCC without distant metastasis; (iii) the presence of portal vein thrombosis (PVT); (iv) Child-Pugh class A or B; and (v) life expectancy of at least 12 weeks. The patients were randomly divided into sorafenib-cryoRx and sorafenib (control) groups. Primary endpoint was time to progression (TTP); secondary endpoints included overall survival (OS) and tolerability. Microvessel density (MVD) was assessed by CD34-immunostaining. After a median 10.5 (4–26) months follow-up, the data showed that median TTP was 9.5 (8.4–13.5) months in combinatorial therapy group vs. 5.3 (3.8–6.9) months in sorafenib group (P = 0.02). The median OS was 12.5 (95 % CI 10.6–16.4) months in combination therapy group vs. 8.6 (7.3–10.4) months in sorafenib group (P = 0.01). Low MVD patients in combination therapy exhibited significantly longer median TTP and OS than controls. High MVD was predictive of poor responses to sorafenib. CryoRx did not increase frequency/degree of sorafenib-related adverse events. Therefore, it was concluded that the addition of cryoRx significantly improved clinical outcomes of Sorafenib therapy in advanced HCC with acceptable tolerance and similar safety profiles as previously reported.

More than just tumor destruction: immunomodulation by thermal ablation of cancer

Over the past decades, thermoablative techniques for the therapy of localized tumors have gained importance in the treatment of patients not eligible for surgical resection. Anecdotal reports have described spontaneous distant tumor regression after thermal ablation, indicating a possible involvement of the immune system, hence an induction of antitumor immunity after thermoinduced therapy. In recent years, a growing body of evidence for modulation of both adaptive and innate immunity, as well as for the induction of danger signals through thermoablation, has emerged. Induced immune responses, however, are mostly weak and not sufficient for the complete eradication of established tumors or durable prevention of disease progression, and combination therapies with immunomodulating drugs are being evaluated with promising results. This article aims to summarize published findings on immune modulation through radiofrequency ablation, cryoablation, microwave ablation therapy, high-intensity focused ultrasound, and laser-induced thermotherapy.

Cryotherapy is associated with improved clinical outcomes of sorafenib for the treatment of advanced hepatocellular carcinoma

Sorafenib may prolong survival in patients with advanced hepatocellular carcinoma (HCC), but with limited efficacy. The present study aimed to assess the safety and efficacy of sorafenib combined with cryotherapy (cryoRx) for the treatment of advanced HCC. A total of 104 patients met the following criteria: advanced HCC without distant metastasis, presence of portal vein thrombosis, Child-Pugh class A or B and life expectancy of at least 12 weeks. All patients were randomly assigned to sorafenib and cryoRx (n=52) or sorafenib-alone (n=52) treatment groups. The primary end-point of the study was overall survival (OS). The secondary end-points included time to progression (TTP) and tolerability. Microvessel density (MVD) was assessed following immunostaining for CD34. In a median of 10.5 (4-26) months follow-up, the median OS was 12.5 months (95% CI 10.6-16.4) in the combination therapy vs. 8.6 months (7.3-10.4) in the sorafenib-alone (P=0.01) group. The median TTP was 9.5 months (8.4-13.5) in the combination therapy vs. 5.3 months (3.8-6.9) in the sorafenib alone (P=0.02) group. CryoRx was an independent factor associated with improved clinical outcomes of sorafenib for the treatment of advanced HCC. Patients with low intratumoral MVD receiving the combination therapy exhibited a significantly longer median TTP and OS compared to those receiving sorafenib. High intratumoral MVD was an independent predictor of poor responses to sorafenib for advanced HCC. Compared with previous reports of sorafenib-related adverse drug reactions (ADRs), cryoRx did not further increase the frequency and degree of sorafenib-related ADRs. In conclusion, compared to sorafenib alone, the addition of cryoRx to sorafenib significantly improves the clinical outcomes of sorafenib for the treatment of advanced HCC with acceptable tolerance and similar safety profiles as previously reported. High intratumoral MVD is predictive of poor responses to sorafenib in advanced HCC patients.

Induction of specific cellular and humoral responses against renal cell carcinoma after combination therapy with cryoablation and granulocyte-macrophage colony stimulating factor: a pilot study

Cryotherapy offers a minimally invasive treatment option for the management of both irresectable and localized prostate, liver, pulmonary, and renal tumors. The antineoplastic effects of cryotherapy are mediated by direct tumor lysis and by indirect effects, such as intracellular dehydration, pH changes, and microvascular damage resulting in ischemic necrosis. In this study, we investigated whether percutaneous cryoablation of lung metastasis from renal cell carcinoma (RCC) in combination with aerosolized granulocyte-macrophage colony stimulating factor can induce systemic cellular and humoral immune responses in 6 patients with RCC. Peripheral blood mononuclear cells (PBMCs) were sequentially studied up to 63 days post cryoimmunotherapy (CI). PBMC from pre and post CI were phenotyped for lymphocyte subsets and tested for cytotoxicity and interferon-γ EliSpots directed at RCC cells. Humoral responses were measured by in vitro antibody synthesis assay directed at RCC cells. The immune monitoring data showed that CI induced tumor specific cytotoxic T lymphocyte, specific in vitro antitumor antibody responses, and enhanced Th1 cytokine production in 4 of 6 patients. More importantly, the magnitude of cellular and humoral antitumor response seems to be associated with clinical responses. These pilot data show that CI can induce robust and brisk cellular and humoral immune responses in patients with metastatic RCC, but requires further evaluation in optimized protocols.

Upregulation of circulating PD-L1/PD-1 is associated with poor post-cryoablation prognosis in patients with HBV-related hepatocellular carcinoma

Background

The programmed cell death-1 receptor/programmed cell death-1 ligand (PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity. This study was designed to evaluate the association between circulating PD-L1/PD-1 and prognosis after cryoablation in patients with HBV-related hepatocellular carcinoma (HCC).

Methodology/Principal Findings

In the present study, 141 HBV-related HCC patients were enrolled and of those 109 patients received cryoablation. Circulating PD-L1/PD-1 expression was tested by flow cytometry, and 23 patients were simultaneously evaluated for intratumoral PD-L1 expression by immunohistochemical staining. Circulating PD-1/PD-L1 expression was associated with severity of diseases in patients with HCC, and the circulating PD-L1 expression was closely correlated with intratumoral PD-L1 expression. Of the clinical parameters, PD-1/PD-L1 expression was associated with tumor size, blood vessel invasion and BCLC staging. Moreover, PD-1/PD-L1 expression dropped after cryoablation while being elevated at the time of tumor recurrence. Patients with higher expression of circulating PD-L1, as well as circulating PD-1, had a significantly shorter overall survival and tumor-free survival than those with lower expression. Multivariate analysis confirmed that circulating PD-L1 could serve as an independent predictor of overall survival and tumor-recurrence survival in HCC patients after cryoablation.

Conclusions/Significance

Upregulation of circulating PD-L1/PD-1 is associated with poor post-cryoablation prognosis in patients with HBV-related hepatocellular carcinoma.

Cryoimmunology for malignant bone and soft-tissue tumors

Several new methods have recently been developed for the treatment of malignant bone and soft-tissue tumors, and many of these targeted therapies have yielded promising initial results in clinical settings. As more sarcomas become amenable to effective molecular-targeting therapy, the need to evaluate the synergistic effects of combination therapies with anticancer drugs will grow. Other immunologic therapies have also been reported, such as exogenous cytokines, dendritic cell (DC) therapy and peptide vaccines. Cryoimmunology has shown promising results in some malignant tumors after cryosurgery and is expected to influence the next generation of tumor immunotherapy. In this report, we describe the induction of a systemic antitumor immune response following liquid nitrogen cryotreatment of a destructive murine osteosarcoma. Combining tumor cryotreatment with DCs to promote tumor-specific immune responses enhanced systemic immune responses and inhibited metastatic tumor growth. We also describe the induction of a systemic antitumor immune response following reconstruction for malignant bone tumors using frozen autografts treated with liquid nitrogen.

Changes in interleukin-1β and 6 after hepatic microwave tissue ablation compared with radiofrequency, cryotherapy and surgical resections

BACKGROUND

Cytokine changes after microwave tissue ablation (MTA) were compared with hepatic resection, cryotherapy (CRYO), and radiofrequency ablation (RFA). Cytokine production was measured at various ablation volumes for each modality and correlated with the transitional inflammatory zone produced by the ablation techniques.

METHODS

Live rats underwent MTA, surgical resection, CRYO or RFA of 15%, 33%, or 66% of the total hepatic volume. Serum samples were collected preoperatively and at 1, 3, 6, 24, and 48 hours after surgery and analyzed for pro-inflammatory cytokines interleukin (IL)-1β and IL-6.

RESULTS

Significantly higher levels of both cytokines were present after CRYO and RFA compared with MTA, hepatic resection, or controls (P < .001). All animals survived except those undergoing RFA or CRYO of 66% of the hepatic volume, which died within 6 hours. Transitional zones produced after RFA were larger than those after CRYO or MTA, but no correlation was present with the amount of cytokines.

CONCLUSIONS

Large-volume MTA is associated with a significant decreased cytokine response and is well tolerated compared with RFA and CRYO.

Regulatory T cells are associated with post-cryoablation prognosis in patients with hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

We carried out this study to evaluate the association between regulatory T cells (Treg) and prognosis and progression after cryoablation in patients with hepatitis-B virus-related hepatocellular carcinoma.

METHODS

Peripheral Treg frequency in 111 patients with hepatocellular carcinoma (HCC) was detected by flow cytometry. Treg frequency and function were re-examined during patient follow up. A possible association between Treg and α-fetoprotein (AFP) was also analyzed, and the distribution of resident CD4(+) and CD8(+) T cells and FoxP3(+) T cells in the liver tissue of patients with HCC was examined by immunohistochemistry.

RESULTS

Treg frequency significantly increased with disease progression. Our longitudinal study showed that Treg frequency had significantly decreased in 17 patients with HCC regression following cryoablation, but the frequency had dramatically increased in 14 patients with HCC recurrence or progression. Furthermore, AFP levels varied in a way comparable with Treg frequency in patients with elevated AFP recorded before therapy. Significantly increased suppressive effects of Treg on proliferation and cytokine secretion of CD8(+) and CD4(+) T cells were observed during follow up in patients with tumor progression, but not in patients with tumor response. Moreover, the numbers of CD8(+), CD4(+), and FoxP3(+) cells infiltrating the tumors around the cryotherapeutic zones were significantly decreased after argon-helium cryoablation, and this was associated with a reduction in the FoxP3/CD8 ratio. Importantly,increased quantities of circulating CD4(+)CD25(+)FoxP3(+) Treg and tumor infiltrating FoxP3(+) cells before cryoablation were associated with high recurrence or risk of progression in HCC patients after cryoablation.

CONCLUSIONS

Treg variation is associated with tumor regression or progression in HCC following cryoablation and may be used as a marker to estimate HCC progression.

Differential effects of propofol and isoflurane on the activation of T-helper cells in lung cancer patients

It is suggested that activation and differentiation of T-helper cells are required for peri-operative anti-tumor and anti-infection immunity. The present study aimed to evaluate whether propofol stimulates the activation and differentiation of these cells in patients undergoing pulmonary lobectomy for non-small-cell lung cancer. Thirty patients were randomly allocated to receive propofol or isoflurane throughout surgery. The CD4(+)CD28(+) percentage (p < 0.0001) and the ratio of interferon-gamma:interleukin-4 (p = 0.001) all increased with propofol but showed no change with isoflurane. In contrast, cortisol increased with isoflurane (p < 0.0001) but not with propofol over time (p = 0.06). We conclude that propofol promotes activation and differentiation of peripheral T-helper cells.

Effect of argon-helium cryoablation on cell apoptosis and T-cell immunity in rats subcutaneously implanted with breast cancer cells

AIM: To investigate the effects of argon-helium (Ar-He) cryoablation on cell apoptosis and T-cell immunity in rats subcutaneously implanted with breast cancer cells.

METHODS: Forty-five healthy male Sprague-Dawley rats were randomly divided into three groups: normal control group, cancer control group and cryoablation group. A xenograft rat model of breast cancer was established by subcutaneous injection of breast cancer cells (W-256) into Sprague-Dawley rats. After argon-helium cryoablation, cell necrosis was observed under light microscopy, cell apoptosis in peripheral cryoablation zone was detected by terminal deoxynucleotidyl transferase-mediated dUTP in situ nick end labeling (TUNEL), and the proliferation of cytotoxic T lymphocytes was investigated using mixed lymphocyte reaction assay.

RESULTS: In central cryoablation zone, necrosis dominated in cell death. In peripheral cryoablation zone, cell apoptosis was definitely observed by morphological examination under light microscopy or TUNEL staining. The apoptosis reached the peak at 12 h after cryoablation, with an apoptosis rate of (68.28 ± 7.85)%. Cryoablation could effectively activate the proliferation of cytotoxic T lymphocytes. The proliferation rate of cytotoxic T lymphocytes in the cryoablation group was significantly higher than that in the cancer control group (P < 0.01).

CONCLUSION: Argon-helium cryoablation can effectively cause cell death either through inducing necrosis or apoptosis. Cryoablation may induce cell apoptosis in peripheral cryoablation zone. Besides, cryosurgery can effectively activate tumor antigen-specific T lymphocytes and improve T cell-mediated immunity.

Enhancing immune responses to tumor-associated antigens

The goal of vaccine-based cancer immunotherapy is to induce a tumor-specific immune response that ultimately reduces tumor burden. However, the immune system is often tolerant to antigens presented by the tumor, as the cancer originates from within a patient and is therefore recognized as self. This article reviews selected clinical strategies for overcoming this immune tolerance, and approaches to enhance generation of immunity to tumor-associated antigens by activating innate immunity, potentiating adaptive immunity, reducing immunosuppression, and enhancing tumor immunogenicity. Success in the field of cancer vaccines has yet to be fully realized, but intelligent choice of immunomodulators, tumor antigens and patient populations will likely lead to clinically relevant uses for cancer vaccines.

Combined cryoablation and GM-CSF treatment for metastatic hormone refractory prostate cancer

A total of 12 patients with metastatic hormone refractory prostate cancer were treated by combining cryoablation and granulocyte macrophage colony-stimulating factor administration. Besides prostate-specific antigen (PSA) measurements, peripheral blood mononuclear cells were also obtained; the frequency of tumor-specific T cells was tested ex vivo in an interferon-gamma enzyme-linked immunospot assay after stimulating with autologous prostate cancer-derived protein lysates. To assess cytolytic activity, T cells were coincubated with human prostate cancer cells (LNCaP) or renal cancer cells (GRC-1), and release of cytosolic adenylate kinase was measured by a luciferase assay. The median PSA decline percentage was 69.4% (range: 30.5% to 92.5%) and the median time to the nadir PSA was 4 months after therapy (range: 3 to 6). The median time to disease progress was 18 months, and 1 patient obtained a 92.5% PSA decline and a greater than 50% reduction of lung disease and survived 31 months. Four or 8 weeks after treatment, the tumor-specific T-cell responses were increased in peripheral blood mononuclear cell. The cytolytic activity against LNCaP was also increased significantly whereas no response was found against GRC-1. It seemed that there was no direct correlation between the degree of T-cell response and decline in PSA. Combined cryoablation with granulocyte macrophage colony-stimulating factor treatment was suggested to be an alternative approach for metastatic hormone refractory prostate cancer and could induce tumor-specific immunologic response.

Re-implantation of tumour tissue treated by cryotreatment with liquid nitrogen induces anti-tumour activity against murine osteosarcoma

We evaluated the possible induction of a systemic immune response to increase anti-tumour activity by the re-implantation of destructive tumour tissue treated by liquid nitrogen in a murine osteosarcoma (LM8) model. The tumours were randomised to treatment by excision alone or by cryotreatment after excision. Tissue from the tumour was frozen in liquid nitrogen, thawed in distilled water and then re-implanted in the same animal. In addition, some mice received an immunological response modifier of OK-432 after treatment. We measured the levels of interferon-gamma and interleukin-12 cytokines and the cytotoxicity activity of splenocytes against murine LM8 osteosarcoma cells. The number of lung and the size of abdominal metastases were also measured.

Re-implantation of tumour tissue after cryotreatment activated immune responses and inhibited metastatic tumour growth. OK-432 synergistically enhanced the anti-tumour effect. Our results suggest that the treatment of malignant bone tumours by reconstruction using autografts containing tumours which have been treated by liquid nitrogen may be of clinical value.

Immunologic response to primary cryoablation of high-risk prostate cancer

OBJECTIVE

To assess whether a specific cytotoxic T-cell response can be induced in patients with prostate cancer after cryoablation.

MATERIAL AND METHODS

Twenty Patients with high-risk prostate cancer underwent cryoablation. Blood was sampled prior to, 4 and 8 weeks after treatment. Serum cytokine levels were analyzed by ELISA, and the Th1/Th2 ratio was estimated from the IFN-gamma/IL-4 ratio. Peripheral blood mononuclear cells (PBMC) were stimulated with autologous prostate cancer-derived protein lysates, and frequency of tumor-specific T-cells was tested ex vivo in an IFN-gamma ELISPOT assay. To assess cytolytic activity, T-cells were co-incubated with human prostate cancer cells, LNCaP, or with renal cancer cells, GRC-1, and release of cytosolic adenylate kinase was measured by a luciferase assay.

RESULT

4 weeks after cryoablation significantly higher levels of TNF-alpha and IFN-gamma were observed compared to before treatment, and to 8 weeks after treatment. No changes in IL-4 or IL-10 were observed. The Th1/Th2 ratio (10.47+/-0.80), 4 weeks after treatment, was increased compared to before treatment (3.98+/-0.45), but decreased 8 weeks later (7.65+/-0.64). Tumor-specific T-cell responses were evident after cryosurgery in PBMC. Cytolytic activity against LNCaP was increased 4 weeks after treatment compared to before treatment (594.49+/-154.84 versus 4.20+/-0.68, P<0.01), but was decreased 8 weeks later (79.70+/-18.73). No response was found in cytolytic activity against GRC-1.

CONCLUSION

Cryoablation of prostate cancer can improve tumor-specific cytotoxic T-cell stimulation with a dramatically increased tumor specific cytolytic activity. However, the response is not sufficiently maintained to prevent cancer relapse.

The anti-tumor effect of allogeneic bone marrow/stem cell transplant without graft vs. host disease toxicity and without a matched donor requirement?

The anti-tumor immune response that occurs in allogeneic bone marrow/stem cell transplant (BMT) settings is capable of eradicating tumors that are resistant to chemotherapy/radiation treatment. This anti-tumor immune response, known as the graft vs. tumor (GVT) effect, is the most effective immunotherapy treatment ever discovered. Unfortunately, the clinical application of GVT is severely limited due to the intimate association of GVT with the extremely toxic and often lethal side-effect known as graft vs. host disease (GVHD). It is a major research focus in the field of BMT to develop methods to separate the beneficial GVT effect from the detrimental GVHD toxicity. However, due to the intimate association of these effects, attempts to limit GVHD also have a tendency to limit the GVT effect. We propose a new concept for harnessing the power of the GVT effect without the toxicity of GVHD. Rather than trying to separate GVT from GVHD, we propose that these naturally coupled effects can 'mirrored' onto the host immune system and maintain their intimate association. The 'mirror' of GVHD is a host rejection of a graft (HVG). As rejection of an allograft would not be toxic, an HVG effect coupled to a host vs. tumor (HVT) effect, the 'mirror' of the GVT effect, would provide the anti-tumor effect of BMT without GVHD toxicity. In the 'mirror' setting, the HVT effect must occur against syngeneic tumors, while in the BMT setting the GVT effect occurs in the allogeneic setting. Previous attempts to elicit syngeneic anti-tumor immunity using therapeutic tumor vaccines have had disappointing results in the clinic due to the influence of tumor immunoavoidance mechanisms. We propose that the 'danger' signals that are released as a result of GVHD in the allogeneic BMT setting serve as an adjuvant to the GVT effect disabling tumor immunoavoidance. The chemotherapy/radiation conditioning prior to transplant is a required initiating event to the coupled GVT/GVHD effects. The conditioning releases 'danger' signals that mediate this adjuvant effect. To imitate this immunological event in immunocompetent, non-conditioned patients we propose that infusion of freshly activated, polyclonal CD4+ memory Th1 cells which express CD40L on the cell surface will stimulate a HVT/HVG 'mirror' effect, providing a non-toxic means to elicit the effective immune-mediated anti-tumor effect of BMT without the GVHD toxicity and without the requirement for a matched donor.