The efficacy of tumor debulking surgery is improved by adjuvant immunotherapy using imiquimod and anti-CD40

Identifying optimal candidates for primary tumor surgery in patients with metastatic head and neck cancer

Background

Primary tumor surgery (PTS) may enhance survival among part of patients with metastatic head and neck cancer (mHNC). Herein, a predictive model was needed to construct to identify who can gain benefit remarkably from tumor resection.

Methods

Data of patients with mHNC were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The best cut-off value of age were analyzed using the X-tile software. One-to-one PSM, Kaplan-Meier method, and log-rank test were performed for survival analysis.The independent factors determined using the multivariate Cox proportional hazard regression were used to construct the nomogram.

Results

A total of 1,614 patients diagnosed with mHNC were included; among them, 356 (22.0%) underwent a surgical procedure for the excision of the primary tumor. cancer-specific survival (CSS) was remarkably prolonged in the PTS group relative to the non-PTS group following PSM [Median:19 months vs. 9 months; hazard ratio (HR) 0.52, P < 0.001]. Patients with mHNC who were younger than 52 years old, had well-differentiated tumors, had T1 and N0 stages, and were married at the time of the study may have significantly benefited from PTS. In addition, we constructed a nomogram based on the factors that independently affect the CSS in multivariate Cox analysis. The nomogram showed excellent discrimination in both the training and validation sets (AUC: 0.732 and 0.738, respectively).

Conclusion

A practical predictive model was constructed to determine the appropriate patients with mHNC, who would benefit from surgical resection.

Percutaneous Intratumoral Immunoadjuvant Gel Increases the Abscopal Effect of Cryoablation for Checkpoint Inhibitor Resistant Cancer

Percutaneous cryoablation is a common clinical therapy for metastatic and primary cancer. There are rare clinical reports of cryoablation inducing regression of distant metastases, known as the "abscopal" effect. Intratumoral immunoadjuvants may be able to augment the abscopal rate of cryoablation, but existing intratumoral therapies suffer from the need for frequent injections and inability to confirm target delivery, leading to poor clinical trial outcomes. To address these shortcomings, an injectable thermoresponsive gel-based controlled release formulation is developed for the FDA-approved Toll-like-receptor 7 (TLR7) agonist imiquimod ("Imigel") that forms a tumor-resident depot upon injection and contains a contrast agent for visualization under computed tomography (CT). The poly-lactic-co-glycolic acid-polyethylene glycol-poly-lactic-co-glycolic acid (PLGA-PEG-PLGA)-based amphiphilic copolymer gel's underlying micellar nature enables high drug concentration and a logarithmic release profile that is additive with the neo-antigen release from cryoablation, requiring only a single injection. Rheological testing demonstrated the thermoresponsive increase in viscosity at body temperature and radio-opacity via microCT. Its ability to significantly augment the abscopal rate of cryoablation is demonstrated in otherwise immunotherapy resistant metastatic tumors in two aggressive colorectal and breast cancer dual tumor models with an all or nothing response, responders generally demonstrating complete regression of bilateral tumors in 90-day survival studies.

Targeted Radium Alpha Therapy in the Era of Nanomedicine: In Vivo Results

Targeted alpha-particle therapy using radionuclides with alpha emission is a rapidly developing area in modern cancer treatment. To selectively deliver alpha-emitting isotopes to tumors, targeting vectors, including monoclonal antibodies, peptides, small molecule inhibitors, or other biomolecules, are attached to them, which ensures specific binding to tumor-related antigens and cell surface receptors. Although earlier studies have already demonstrated the anti-tumor potential of alpha-emitting radium (Ra) isotopes-Radium-223 and Radium-224 (223/224Ra)-in the treatment of skeletal metastases, their inability to complex with target-specific moieties hindered application beyond bone targeting. To exploit the therapeutic gains of Ra across a wider spectrum of cancers, nanoparticles have recently been embraced as carriers to ensure the linkage of 223/224Ra to target-affine vectors. Exemplified by prior findings, Ra was successfully bound to several nano/microparticles, including lanthanum phosphate, nanozeolites, barium sulfate, hydroxyapatite, calcium carbonate, gypsum, celestine, or liposomes. Despite the lengthened tumor retention and the related improvement in the radiotherapeutic effect of 223/224Ra coupled to nanoparticles, the in vivo assessment of the radiolabeled nanoprobes is a prerequisite prior to clinical usage. For this purpose, experimental xenotransplant models of different cancers provide a well-suited scenario. Herein, we summarize the latest achievements with 223/224Ra-doped nanoparticles and related advances in targeted alpha radiotherapy.

Case report: Patient specific combination of surgery and immunotherapy in advanced squamous cell carcinoma of the head and neck - a case series and review of literature

BACKGROUND

Prognosis of patients with recurrent or metastatic head and neck cancer is generally poor. Adjuvant immunotherapy (IT) featuring immune checkpoint inhibition (ICI) is standard of care in advanced stage head and neck squamous cell carcinoma (HNSCC) and cutaneous squamous cell carcinoma (CSCC). ICI response rates in CSCC are described as higher than in HNSCC. IT is constantly shifting into earlier disease stages which confronts the surgeon with immunotherapeutically pre-treated patients. It is therefore becoming increasingly difficult to assess which patients with symptomatic tumor disease and a lack of curative surgical option might benefit from salvage surgery.

CASE PRESENTATIONS

The following 6 cases describe therapeutic decision-making regarding ICI and (salvage) surgery in patients with advanced stage HNSCC or CSCC. Cases A and B focus on neoadjuvant ICI followed by salvage surgery. In Cases C and D salvage surgery was performed after short-term stabilization with partial response to ICI. The last two cases (Cases E and F) address the surgical approach after failure of ICI. All cases are discussed in the context of the current study landscape and with focus on individual decision-making. For better understanding, a timetable of the clinical course is given for each case.

CONCLUSIONS

ICI is rapidly expanding its frontiers into the neoadjuvant setting, frequently confronting the surgeon with heavily pretreated patients. Salvage surgery is a viable therapeutic concept despite the rise of systemic treatment options. Decision-making on surgical intervention in case of a salvage surgery remains an individual choice. For neoadjuvant ICI monitoring regarding pathological tumor response or tumor necrosis rate, we suggest correlation between the initial biopsy and the definite tumor resectate in order to increase its significance as a surrogate marker. Scheduling of neoadjuvant ICI should be further investigated, as recent studies indicate better outcomes with shorter time frames.

How Our Continuing Studies of the Pre-clinical Inbred Mouse Models of Mesothelioma Have Influenced the Development of New Therapies

Asbestos-induced preclinical mouse models of mesothelioma produce tumors that are very similar to those that develop in humans and thus represent an ideal platform to study this rare, universally fatal tumor type. Our team and a number of other research groups have established such models as a stepping stone to new treatments, including chemotherapy, immunotherapy and other approaches that have been/are being translated into clinical trials. In some cases this work has led to changes in mesothelioma treatment practice and over the last 30 years these models and studies have led to trials which have improved the response rate in mesothelioma from less than 10% to over 50%. Mouse models have had a vital role in that improvement and will continue to play a key role in the future success of mesothelioma immunotherapy. In this review we focus only on these original inbred mouse models, the large number of preclinical studies conducted using them and their contribution to current and future clinical therapy for mesothelioma.

CD40 stimulation as a molecular adjuvant for cancer vaccines and other immunotherapies

The substantial advances attained by checkpoint blockade immunotherapies have driven an expansion in the approaches used to promote T cell access to the tumor microenvironment to provide targets for checkpoint immunotherapy. Inherent in any T cell response to a tumor antigen is the capacity of dendritic cells to initiate and support such responses. Here, the rationale and early immunobiology of CD40 as a master regulator of dendritic cell activation is reviewed, with further contextualization and appreciation for the role of CD40 stimulation not only in cancer vaccines but also in other contemporary immune-oncology approaches.

Orosomucoid 1 promotes epirubicin resistance in breast cancer by upregulating the expression of matrix metalloproteinases 2 and 9

Orosomucoid 1 (ORM1) has been shown to be upregulated in the serum of breast cancer patients; however, the expression and function of ORM1 in breast cancer remains unknown. We measured the expression of ORM1 in breast cancer tissues and cell lines using qRT-PCR. A colony formation assay was done to assess cell proliferation and Transwell and wound healing assays were performed to determine the migration and invasion capacity of the cells, respectively. In addition, a CCK-8 assay was used to measure epirubicin cytotoxicity and western blot assays were done to analyze the putative mechanisms of epirubicin sensitivity. We found that the expression of ORM1 was upregulated in breast cancer tissues and cell lines. The expression of ORM1 enhanced the proliferation and migration of the cell lines. In contrast, down-regulation of ORM1 inhibited the expression of MMP-2 and MMP-9 and activation of the AKT/ERK signaling pathway. Therefore, ORM1 may represent a potential therapeutic target for breast cancer and promote epirubicin resistance by regulating the expression of MMP-2 and MMP-9, as well as activating the AKT/ERK signaling pathway.

Radiation-induced bystander and abscopal effects: important lessons from preclinical models

Radiotherapy is a pivotal component in the curative treatment of patients with localised cancer and isolated metastasis, as well as being used as a palliative strategy for patients with disseminated disease. The clinical efficacy of radiotherapy has traditionally been attributed to the local effects of ionising radiation, which induces cell death by directly and indirectly inducing DNA damage, but substantial work has uncovered an unexpected and dual relationship between tumour irradiation and the host immune system. In clinical practice, it is, therefore, tempting to tailor immunotherapies with radiotherapy in order to synergise innate and adaptive immunity against cancer cells, as well as to bypass immune tolerance and exhaustion, with the aim of facilitating tumour regression. However, our understanding of how radiation impacts on immune system activation is still in its early stages, and concerns and challenges regarding therapeutic applications still need to be overcome. With the increasing use of immunotherapy and its common combination with ionising radiation, this review briefly delineates current knowledge about the non-targeted effects of radiotherapy, and aims to provide insights, at the preclinical level, into the mechanisms that are involved with the potential to yield clinically relevant combinatorial approaches of radiotherapy and immunotherapy.

The Potential of Tumor Debulking to Support Molecular Targeted Therapies

Tumors may consist of billions of cells, which in malignant cases disseminate and form distant metastases. The large number of tumor cells formed by the high number of cell divisions during tumor progression creates a heterogeneous set of genetically diverse tumor cell clones. For cancer therapy this poses unique challenges, as distinct clones have to be targeted in different tissue locations. Recent research has led to the development of specific inhibitors of defined targets in cellular signaling cascades which promise more effective and more tumor-specific therapy approaches. Many of these molecular targeted therapy (MTT) compounds have already been translated into clinics or are currently being tested in clinical studies. However, the outgrowth of tumor cell clones resistant to such inhibitors is a drawback that affects specific inhibitors in a similar way as classical cytotoxic chemotherapeutics, because additionally acquired genetic alterations can enable tumor cells to circumvent the particular regulators of cellular signaling being targeted. Thus, it might be desirable to reduce genetic heterogeneity prior to molecular targeting, which could reduce the statistical chance of tumor relapse initiated by resistant clones. One way to achieve this is employing unspecific methods to remove as much tumor material as possible before MTT, e.g., by tumor debulking (TD). Currently, this is successfully applied in the clinical treatment of ovarian cancer. We believe that TD followed by treatment with a combination of molecular targeted drugs, optimally guided by biomarkers, might advance survival of patients suffering from various cancer types.

A curative treatment strategy using tumor debulking surgery combined with immune checkpoint inhibitors for advanced pediatric solid tumors: An in vivo study using a murine model of osteosarcoma

BACKGROUND/PURPOSE

This study aimed to assess the significance of tumor debulking surgery by using immune checkpoint inhibitors for advanced pediatric solid tumors in a murine model of advanced osteosarcoma.

METHODS

In C3H mice, 5 × 10⁶ LM8 (osteosarcoma cell line with a high metastatic potential in the lungs originating from the C3H mouse) cells were transplanted subcutaneously. Thereafter, the mice were divided into 4 groups as follows: the control group received no intervention (CG, n = 5), the surgery group underwent subcutaneous tumor resection (tumor debulking surgery) 11 days after transplantation (SG, n = 10), the immunotherapy group received a cocktail consisting of 200 μg each of three antibodies (anti-Tim-3, anti-PD-L1, and anti-OX-86) intraperitoneally on posttransplantation days 11, 14, 18, and 21 (IG, n = 10), and the combination therapy group, tumor debulking surgery on day 11 and the cocktail intraperitoneally on days 11, 14, 18, and 21 (COMBG, n = 10). Survival curves were plotted by using the Kaplan-Meier method and compared with those plotted using the log-rank test. Next, the lungs of mice in the 4 groups were pathologically evaluated.

RESULTS

The COMBG showed significantly longer survival than the other three groups (P ≤ 0.002), whereas the SG and IG revealed no difference in survival rate compared to CG. Pathological evaluations revealed no lung metastasis 16 weeks after tumor transplantation in the survivors of COMBG.

CONCLUSIONS

The results of this study suggest that tumor debulking surgery combined with immune checkpoint inhibitors could be a curative treatment for advanced pediatric solid tumors.

Local Option: The Rational Use of Local Therapy in Patients at High Risk to Die of Metastatic Progression

On occasion, clinicians may be motivated to offer local therapy (eg, surgery, radiation, ablation) to patients with advanced cancer in the hope of prolonging survival (as opposed to palliating a symptom). An appropriately informed discussion of risks and benefits should push clinicians to reflect on the rationale for use of local therapy in a patient who is far more likely to die as a result of systemic progression. Ultimately, the justification for local therapy in advanced cancer must be based on several assumptions of what a patient’s cancer will and will not do. The following is an attempt to provide the framework for patients and their care teams to collectively consider the assumptions surrounding the use of local therapy and the potential consequences of being wrong.

The use of functional epirubicin liposomes to induce programmed death in refractory breast cancer

Currently, chemotherapy is less efficient in controlling the continued development of breast cancer because it cannot eliminate extrinsic and intrinsic refractory cancers. In this study, mitochondria were modified by functional epirubicin liposomes to eliminate refractory cancers through initiation of an apoptosis cascade. The efficacy and mechanism of epirubicin liposomes were investigated on human breast cancer cells in vitro and in vivo using flow cytometry, confocal microscopy, high-content screening system, in vivo imaging system, and tumor inhibition in mice. Mechanistic studies revealed that the liposomes could target the mitochondria, activate the apoptotic enzymes caspase 8, 9, and 3, upregulate the proapoptotic protein Bax while downregulating the antiapoptotic protein Mcl-1, and induce the generation of reactive oxygen species (ROS) through an apoptosis cascade. In xenografted mice bearing breast cancer, the epirubicin liposomes demonstrated prolonged blood circulation, significantly increased accumulation in tumor tissue, and robust anticancer efficacy. This study demonstrated that functional epirubicin liposomes could significantly induce programmed death of refractory breast cancer by activating caspases and ROS-related apoptotic signaling pathways, in addition to the direct killing effect of the anticancer drug itself. Thus, we present a simple nanomedicine strategy to treat refractory breast cancer.

Transient Treg depletion enhances therapeutic anti-cancer vaccination

INTRODUCTION

Regulatory T cells (Treg) play an important role in suppressing anti- immunity and their depletion has been linked to improved outcomes. To better understand the role of Treg in limiting the efficacy of anti-cancer immunity, we used a Diphtheria toxin (DTX) transgenic mouse model to specifically target and deplete Treg.

METHODS

Tumor bearing BALB/c FoxP3.dtr transgenic mice were subjected to different treatment protocols, with or without Treg depletion and tumor growth and survival monitored.

RESULTS

DTX specifically depleted Treg in a transient, dose-dependent manner. Treg depletion correlated with delayed tumor growth, increased effector T cell (Teff) activation, and enhanced survival in a range of solid tumors. Tumor regression was dependent on Teffs as depletion of both CD4 and CD8 T cells completely abrogated any survival benefit. Severe morbidity following Treg depletion was only observed, when consecutive doses of DTX were given during peak CD8 T cell activation, demonstrating that Treg can be depleted on multiple occasions, but only when CD8 T cell activation has returned to base line levels. Finally, we show that even minimal Treg depletion is sufficient to significantly improve the efficacy of tumor-peptide vaccination.

CONCLUSIONS

BALB/c.FoxP3.dtr mice are an ideal model to investigate the full therapeutic potential of Treg depletion to boost anti-tumor immunity. DTX-mediated Treg depletion is transient, dose-dependent, and leads to strong anti-tumor immunity and complete tumor regression at high doses, while enhancing the efficacy of tumor-specific vaccination at low doses. Together this data highlight the importance of Treg manipulation as a useful strategy for enhancing current and future cancer immunotherapies.

Moving Immune Checkpoint Blockade in Thoracic Tumors beyond NSCLC

SCLC and malignant pleural mesothelioma (MPM) are historically characterized by a disappointing lack of significant therapeutic breakthroughs for novel agents, and both malignancies represent true unmet medical needs. Given the promising results of anti-cytotoxic T-lymphocyte associated protein-4 and anti-programmed cell death-1/programmed death ligand-1 antibodies in the treatment of advanced NSCLCs, these immune checkpoint inhibitors are now also under investigation in SCLC and MPM, as well as in thymic epithelial tumors (TETs). Here, we review the biological and clinical rationale for immune checkpoint inhibition in SCLC, MPM, and TETs and present preliminary clinical results with available antibodies. Immunotherapeutic perspectives for these malignancies in terms of novel agents currently under evaluation or anticipated in the near future are also discussed. Current immune checkpoint blockers targeting cytotoxic T-lymphocyte associated protein-4 and the programmed cell death-1/programmed death ligand-1 axis, administered alone or in combination and as multimodality treatment, are likely to be a valuable addition to the therapeutic array for managing SCLC and MPM; studies in TETs, which are currently in their infancy, are merited. Close attention to potential toxicities will be important to the success of such strategies in these settings.

Immunotherapy for lung cancer

Treatment of lung cancer remains a challenge, and lung cancer is still the leading cause of cancer-related mortality. Immunotherapy has previously failed in lung cancer but has recently emerged as a very effective new therapy, and there is now growing worldwide enthusiasm in cancer immunotherapy. We summarize why immune checkpoint blockade therapies have generated efficacious and durable responses in clinical trials and why this has reignited interest in this field. Cancer vaccines have also been explored in the past with marginal success. Identification of optimal candidate neoantigens may improve cancer vaccine efficacy and may pave the way to personalized immunotherapy, alone or in combination with other immunotherapy such as immune checkpoint blockade. Understanding the steps in immune recognition and eradication of cancer cells is vital to understanding why previous immunotherapies failed and how current therapies can be used optimally. We hold an optimistic view for the future prospect in lung cancer immunotherapy.

Human mesothelioma induces defects in dendritic cell numbers and antigen-processing function which predict survival outcomes

Mesothelioma is an almost invariably fatal tumor with chemotherapy extending survival by a few months. One immunotherapeutic strategy is to target dendritic cells (DCs), key antigen-presenting cells involved in antigen presentation, to induce antigen-specific T cell responses. However, DC-targeting will only be effective if DCs are fit-for-purpose, and the functional status of DCs in mesothelioma patients was not clear. We found that mesothelioma patients have significantly decreased numbers of circulating myeloid (m)DC1 cells, mDC2 cells and plasmacytoid (p)DCs relative to healthy age and gender-matched controls. Blood monocytes from patients could not differentiate into immature monocyte-derived DCs (MoDCs), indicated by a significantly reduced ability to process antigen and reduced expression of costimulatory (CD40, CD80 and CD86) and MHC (HLA-DR) molecules, relative to controls. Activation of mesothelioma-derived MoDCs with LPS+/-IFNγ generated partially mature MoDCs, evident by limited upregulation of the maturation marker, CD83, and the costimulatory markers. Attempts to rescue mesothelioma-derived DC function using CD40Ligand(L) also failed, indicated by maintenance of antigen-processing capacity and limited upregulation of CD40, CD83, CD86 and HLA-DR. These data suggest that mesothelioma patients have significant numerical and functional DC defects and that their reduced capacity to process antigen and reduced expression of costimulatory molecules could induce anergized/tolerized T cells. Nonetheless, survival analyses revealed that individuals with mesothelioma and higher than median levels of mDC1s and/or whose MoDCs matured in response to LPS, IFNγ or CD40L lived longer, implying their selection for DC-targeting therapy could be promising especially if combined with another treatment modality.

Epirubicin inhibits growth and alters the malignant phenotype of the U‑87 glioma cell line

Epirubicin, an anthracycline derivative, is one of the main line treatments for brain tumors. The aim of the present study was to verify that epirubicin alters the growth and morphological characteristics of U‑87 glioma cells. In the present study, the effects of epirubicin were tested using cellular and biochemical assays, which demonstrated its anti‑proliferative and cytotoxic effects, with an IC50 of 6.3 µM for the U‑87 cell line, while rat normal neuronal cells were resistant to epirubicin. Epirubicin also reduced the secretion of matrix metalloproteinase‑9 by 48 and 56% at concentrations of 2.5 and 5 µM, respectively. Exposure to epirubicin also diminished levels of vascular endothelial growth factor in U‑87 cells. Furthermore, a cell migration assay showed a significant decrease in cell migration from 28 to 59% following exposure to 1 µM epirubicin. The present study demonstrated the cytotoxic, anti‑proliferative and anti‑migrative potential of epirubicin against glioma cells in vitro.