Using immunotherapy to boost the abscopal effect

Global democratisation of proton radiotherapy

Proton radiotherapy is an advanced treatment option compared with conventional x-ray treatment, delivering much lower doses of radiation to healthy tissues surrounding the tumour. However, proton therapy is currently not widely available. In this Review, we summarise the evolution of proton therapy to date, together with the benefits to patients and society. These developments have led to an exponential growth in the number of hospitals using proton radiotherapy worldwide. However, the gap between the number of patients who should be treated with proton radiotherapy and those who have access to it remains large. We summarise the ongoing research and development that is contributing to closing this gap, including the improvement of treatment efficiency and efficacy, and advances in fixed-beam treatments that do not require an enormously large, heavy, and costly gantry. The ultimate goal of decreasing the size of proton therapy machines to fit into standard treatment rooms appears to be within reach, and we discuss future research and development opportunities to achieve this goal.

Anti-4-1BB immunotherapy enhances systemic immune effects of radiotherapy to induce B and T cell-dependent anti-tumor immune activation and improve tumor control at unirradiated sites

Radiation therapy (RT) can prime and boost systemic anti-tumor effects via STING activation, resulting in enhanced tumor antigen presentation and antigen recognition by T cells. It is increasingly recognized that optimal anti-tumor immune responses benefit from coordinated cellular (T cell) and humoral (B cell) responses. However, the nature and functional relevance of the RT-induced immune response are controversial, beyond STING signaling, and agonistic interventions are lacking. Here, we show that B and CD4+ T cell accumulation at tumor beds in response to RT precedes the arrival of CD8+ T cells, and both cell types are absolutely required for abrogated tumor growth in non-irradiated tumors. Further, RT induces increased expression of 4-1BB (CD137) in both T and B cells; both in preclinical models and in a cohort of patients with small cell lung cancer treated with thoracic RT. Accordingly, the combination of RT and anti-41BB therapy leads to increased immune cell infiltration in the tumor microenvironment and significant abscopal effects. Thus, 4-1BB therapy enhances radiation-induced tumor-specific immune responses via coordinated B and T cell responses, thereby preventing malignant progression at unirradiated tumor sites. These findings provide a rationale for combining RT and 4-1bb therapy in future clinical trials.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

Radiation-induced tumor immune microenvironments and potential targets for combination therapy

As one of the four major means of cancer treatment including surgery, radiotherapy (RT), chemotherapy, immunotherapy, RT can be applied to various cancers as both a radical cancer treatment and an adjuvant treatment before or after surgery. Although RT is an important modality for cancer treatment, the consequential changes caused by RT in the tumor microenvironment (TME) have not yet been fully elucidated. RT-induced damage to cancer cells leads to different outcomes, such as survival, senescence, or death. During RT, alterations in signaling pathways result in changes in the local immune microenvironment. However, some immune cells are immunosuppressive or transform into immunosuppressive phenotypes under specific conditions, leading to the development of radioresistance. Patients who are radioresistant respond poorly to RT and may experience cancer progression. Given that the emergence of radioresistance is inevitable, new radiosensitization treatments are urgently needed. In this review, we discuss the changes in irradiated cancer cells and immune cells in the TME under different RT regimens and describe existing and potential molecules that could be targeted to improve the therapeutic effects of RT. Overall, this review highlights the possibilities of synergistic therapy by building on existing research.

Polydopamine Nanomaterials for Overcoming Current Challenges in Cancer Treatment

In efforts to overcome current challenges in cancer treatment, multifunctional nanoparticles are attracting growing interest, including nanoparticles made with polydopamine (PDA). PDA is a nature-inspired polymer with a dark brown color. It has excellent biocompatibility and is biodegradable, offering a range of extraordinary inherent advantages. These include excellent drug loading capability, photothermal conversion efficiency, and adhesive properties. Though the mechanism of dopamine polymerization remains unclear, PDA has demonstrated exceptional flexibility in engineering desired morphology and size, easy and straightforward functionalization, etc. Moreover, it offers enormous potential for designing multifunctional nanomaterials for innovative approaches in cancer treatment. The aim of this work is to review studies on PDA, where the potential to develop multifunctional nanomaterials with applications in photothermal therapy has been demonstrated. Future prospects of PDA for developing applications in enhancing radiotherapy and/or immunotherapy, including for image-guided drug delivery to boost therapeutic efficacy and minimal side effects, are presented.

Novel Drugs and Radiotherapy in Relapsed Lymphomas: Abscopal Response and Beyond

Combined modality has represented a mainstay of treatment across many lymphoma histologies, given their sensitivity to both multi-agent chemotherapy and intermediate-dose radiotherapy. More recently, several new agents, including immunotherapies, have reshaped the therapeutic panorama of some lymphomas. In parallel, radiotherapy techniques have witnessed substantial improvement, accompanied by a growing understanding that radiation itself comes with an immune-mediated effect. Six decades after a metastatic lesion regression outside the irradiated field was first described, there is increasing evidence that a combination of radiotherapy and immunotherapy could boost an abscopal effect. This review focuses on the mechanisms underlying this interaction in the setting of lymphomas, and on the results of pivotal prospective studies. Furthermore, the available evidence on the concomitant use of radiotherapy and small molecules (i.e., lenalidomide, venetoclax, and ibrutinib), as well as brentuximab vedotin, and chimeric antigen receptor (CAR) T-cell therapy, is summarized. Currently, combining radiotherapy with new agents in patients who are affected by lymphomas appears feasible, particularly as a bridge to anti-CD19 autologous CAR T-cell infusion. However, more studies are required to assess these combinations, and preliminary data suggest only a synergistic rather than a curative effect.

Severe lymphopenia as a prognostic factor in rectal cancer patients receiving adjuvant chemoradiotherapy: a retrospective study

The relationship between total lymphocyte counts (TLCs) and survival is not well documented in rectal cancer. This study aimed to investigate the association between TLCs and disease-free survival (DFS) and identify factors associated with lymphopenia in locally advanced rectal cancer patients receiving chemoradiotherapy. Thirty-six patients with locally advanced rectal cancer were retrospectively analyzed. TLCs were evaluated before surgery (pre-S), before radiotherapy (pre-RT), and during concurrent chemoradiotherapy (CCRT). The relationship between TLCs and DFS was analyzed by univariate and multivariate analysis. Potential clinical factors associated with lymphopenia were also evaluated. Median TLC declined significantly during radiotherapy. Severe lymphopenia during CCRT was significantly associated with poorer DFS on Kaplan-Meier analysis (p = 0.01), univariate regression analysis (p = 0.036), and multivariate regression analysis (p = 0.038). Pre-S TLCs (p = 0.009) and pre-RT TLCs (p = 0.042) were significantly associated with severe lymphopenia on univariate regression analysis; however, only pre-S TLCs (p = 0.026) were significantly associated with severe lymphopenia on multivariate regression analysis. Severe lymphopenia was a predictor of poorer DFS in patients with locally advanced rectal cancer receiving adjuvant chemoradiotherapy. Pre-S TLCs were predictors of severe lymphopenia. Further study is warranted to reduce the rate of severe lymphopenia.

Autologous-cancer-cryoablation-mediated nanovaccine augments systematic immunotherapy

Cancer vaccines developed from autologous tumors hold tremendous promise for individualized cancer immunotherapy. Cryoablation-induced in situ autologous antigens are capable of activating systemic immunity with low damage. However, the dissipation of cancer fragments after cryoablation induces poor immunogenicity and short-time maintenance of immunological memory. To solve this challenge, a nanovaccine with functional grippers is proposed to largely enhance the in situ grasping of tumor fragments, combined with an immune adjuvant to further strengthen the immune-therapeutic effect. Herein, maleimide-modified Pluronic F127-chitosan nanoparticles encapsulating Astragalus polysaccharide (AMNPs) are developed. The AMNPs can capture multifarious and immunogenic tumor antigens generated through cryoablation, specifically target lymph nodes and facilitate lysosome escape to activate remote dendritic cells, and modulate T cell differentiation through cross-presentation, thereby breaking the immunosuppressive microenvironment to achieve durable and robust tumor-specific immunity. In the bilateral Lewis lung cancer tumor model, AMNP-mediated cryoablation can significantly regress primary tumors (with a tumor growth inhibition rate of 100%, and a recurrence rate of 0% (30 days) and 16.67% (60 days)), inhibit untreated abscopal tumor growth (a decrease of about 3.84-fold compared with the saline group), and ultimately improve the long-term survival rate (83.33%). Collectively, the development of a lymph-node-targeted in situ cancer-cryoablation-mediated nanovaccine provides a promising approach for personalized cancer immunotherapy against metastatic cancers.

Neoadjuvant chemoradiotherapy induced lymphopenia in gastric cancer and associations with spleen dosimetry and survival outcomes

Background

Few studies concentrate on spleen dosimetry of radiotherapy for gastric cancer (GC). Although there is no consensus on the spleen dose-volume threshold for lymphopenia, several studies indicated that the higher the spleen dose, the higher the risk of lymphopenia. This study aimed to identify the appropriate spleen dosimetric parameters for predicting grade 4 + lymphopenia in patients with locally advanced GC.

Material and methods

A total of 295 patients treated with nCRT and nChT from June 2013 to December 2021 at two major centers were included, of whom 220 were assigned to the training cohort and 75 to the external validation cohort.

Results

Grade 4 + lymphopenia was more common in the nCRT than in the nChT group (49.5% vs. 0, P < 0.001 in the training cohort; 25.0% vs. 0, P = 0.001 in the external validation cohort). Age ≥ 60 years (P = 0.006), lower pretreatment absolute lymphocyte count (P = 0.001), higher spleen volume (SPV) (P = 0.001), and higher V₂₀ (P = 0.003) were significant risk factors of grade 4 + lymphopenia for patients treated with nCRT. Patients with grade 4 + lymphopenia had significantly worse PFS (P = 0.043) and showed a negative correlation trend with OS (P = 0.07). Limiting V₂₀ to < 84.5% could decrease the incidence of grade 4 + lymphopenia by 35.7%. The predictive effectiveness of the multivariable model in the training and external validation cohorts was 0.880 and 0.737, respectively.

Conclusion

Grade 4 + lymphopenia during nCRT was more common than nChT, and was associated with a worse PFS in GC patients. Constraining the spleen V₂₀ to < 84.5% may indirectly improve outcomes through lymphocyte preservation.

Biomaterials That Induce Immunogenic Cell Death

The immune system takes part in most physiological and pathological processes of the body, including the occurrence and development of cancer. Immunotherapy provides a promising modality for inhibition and even the cure of cancer. During immunotherapy, the immunogenic cell death (ICD) of tumor cells induced by chemotherapy, radiotherapy, phototherapy, bioactive materials, and so forth, triggers a series of cellular responses by causing the release of tumor-associated antigens and damage-associated molecular patterns, which ultimately activate innate and adaptive immune responses. Among them, the ICD-induced biomaterials attract increasing conditions as a benefit of biosafety and multifunctional modifications. This Review summarizes the research progress in biomaterials for inducing ICD via triggering endoplasmic reticulum oxidative stress, mitochondrial dysfunction, and cell membrane rupture and discusses the application prospects of ICD-inducing biomaterials in clinical practice for cancer immunotherapy.

Novel unconventional radiotherapy techniques: Current status and future perspectives - Report from the 2nd international radiation oncology online seminar

•Improvement of therapeutic ratio by novel unconventional radiotherapy approaches.•Immunomodulation using high-dose spatially fractionated radiotherapy.•Boosting radiation anti-tumor effects by adding an immune-mediated cell killing.

Current literature review on the tumor immune micro-environment, its heterogeneity and future perspectives in treatment of advanced non-small cell lung cancer

Background and Objective

Immune checkpoint inhibitors (ICI) were a major clinical advancement that provided an opportunity to improve the prognosis of patients with non-small cell lung cancer (NSCLC). However, programmed death-ligand-1 (PD-L1) expression does not sufficiently predict ICI efficacy in NSCLC patients. In recent studies, the tumor immune microenvironment (TIME) was shown to have a central role in lung cancer progression and to affect clinical outcome of patients diagnosed with lung cancer. As development of new therapeutic targets to overcome ICI resistance is a priority, understanding the TIME is important. Recently, a series of studies was conducted to target each component of TIME to improve efficacy of cancer treatment. In this review, important features related to TIME, its heterogeneity and current trends in treatment targeting the component of TIME are discussed.

Methods

PubMed and PMC were searched from January 1st, 2012 to August 16th, 2022 using the following key words: "NSCLC", "Tumor microenvironment", "Immune", "Metastasis" and "Heterogeneity".

Key Content and Findings

Heterogeneity in the TIME can be either spatial or temporal. Subsequent to heterogeneous changes in the TIME, treatment of lung cancer can be more challenging because drug resistance is more likely to occur. In terms of the TIME, the main concept for increasing the chance of successful NSCLC treatment is to activate immune responses against tumor cells and inhibit immunosuppressive activities. In addition, relevant research is focused on normalizing an otherwise aberrant TIME in NSCLC patients. Potential therapeutic targets include immune cells, cytokine interactions, and non-immune cells such as fibroblasts or vessels.

Conclusions

In management of lung cancer, understanding TIME and its heterogeneity is significant to treatment outcomes. Ongoing trials including various treatment modalities such as radiotherapy, cytotoxic chemotherapy, and anti-angiogenic treatment and regimens inhibiting other immunoinhibitory molecules are promising.

Prospects for the Use of Metal-Based Nanoparticles as Adjuvants for Local Cancer Immunotherapy

Immunotherapy is among the most effective approaches for treating cancer. One of the key aspects for successful immunotherapy is to achieve a strong and stable antitumor immune response. Modern immune checkpoint therapy demonstrates that cancer can be defeated. However, it also points out the weaknesses of immunotherapy, as not all tumors respond to therapy and the co-administration of different immunomodulators may be severely limited due to their systemic toxicity. Nevertheless, there is an established way through which to increase the immunogenicity of immunotherapy-by the use of adjuvants. These enhance the immune response without inducing such severe adverse effects. One of the most well-known and studied adjuvant strategies to improve immunotherapy efficacy is the use of metal-based compounds, in more modern implementation-metal-based nanoparticles (MNPs), which are exogenous agents that act as danger signals. Adding innate immune activation to the main action of an immunomodulator makes it capable of eliciting a robust anti-cancer immune response. The use of an adjuvant has the peculiarity of a local administration of the drug, which positively affects its safety. In this review, we will consider the use of MNPs as low-toxicity adjuvants for cancer immunotherapy, which could provide an abscopal effect when administered locally.

Targeting Myc-driven stress addiction in colorectal cancer

MYC is a proto-oncogene that encodes a powerful regulator of transcription and cellular programs essential for normal development, as well as the growth and survival of various types of cancer cells. MYC rearrangement and amplification is a common cause of hematologic malignancies. In epithelial cancers such as colorectal cancer, genetic alterations in MYC are rare. Activation of Wnt, ERK/MAPK, and PI3K/mTOR pathways dramatically increases Myc levels through enhanced transcription, translation, and protein stability. Elevated Myc promotes stress adaptation, metabolic reprogramming, and immune evasion to drive cancer development and therapeutic resistance through broad changes in transcriptional and translational landscapes. Despite intense interest and effort, Myc remains a difficult drug target. Deregulation of Myc and its targets has profound effects that vary depending on the type of cancer and the context. Here, we summarize recent advances in the mechanistic understanding of Myc-driven oncogenesis centered around mRNA translation and proteostress. Promising strategies and agents under development to target Myc are also discussed with a focus on colorectal cancer.

Large Range Atomic Force Microscopy with High Aspect Ratio Micropipette Probe for Deep Trench Imaging

Atomic force microscopy (AFM) has been adopted in both industry and academia for high-fidelity, full-profile topographic characterization. Typically, the tiny tip of the cantilever and the limited traveling range of the scanner restrict AFM measurement to relatively flat samples (recommend 1 µm). The primary objective of this work is to address these limitations using a large-range AFM (measuring height >10 µm) system consisting of a novel repairable high aspect ratio probe (HARP) with a nested-proportional-integral-derivative (nested-PID) AFM system. The HARP is fabricated using a reliable, cost-efficient bench-top process. The tip is then fused by pulling the end of the micropipette cantilever with a length up to hundreds of micrometers and a tip diameter of 30 nm. The design, simulation, fabrication, and performance of the HARP are described herein. This instrument is then tested using polymer trenches which reveals superior image fidelity compared to standard silicon tips. Finally, a nested-PID system is developed and employed to facilitate 3D characterization of 50-µm-step samples. The results demonstrate the efficacy of the proposed bench-top technique for the fabrication of low-cost, simple HAR AFM probes that facilitate the imaging of samples with deep trenches.

The abscopal effect in patients with cancer receiving immunotherapy

Interest in the abscopal effect has been rekindled over the past decade with the advent of immunotherapy. Although purportedly elusive, this phenomenon is being increasingly reported. Venturing further using a multimodality approach with an array of systemic agents and unconventional modalities is direly needed. In this perspective, we describe the fundamentals of abscopal responses (ARs), explore combinations with systemic therapies that hold promise in eliciting ARs, and reconnoiter unconventional modalities that may induce ARs. Finally, we scrutinize prospective agents and modalities that exhibit preclinical ability to elicit ARs and discuss prognostic biomarkers, their limitations, and pathways of abscopal resistance for reproducibility.

Expansion of circulating stem-like CD8+ T cells by adding CD122-directed IL-2 complexes to radiation and anti-PD1 therapies in mice

Combination of radiation therapy (RT) with immune checkpoint blockade can enhance systemic anti-tumor T cell responses. Here, using two mouse tumor models, we demonstrate that adding long-acting CD122-directed IL-2 complexes (IL-2c) to RT/anti-PD1 further increases tumor-specific CD8+ T cell numbers. The highest increase (>50-fold) is found in the blood circulation. Compartmental analysis of exhausted T cell subsets shows that primarily undifferentiated, stem-like, tumor-specific CD8+ T cells expand in the blood; these cells express the chemokine receptor CXCR3, which is required for migration into tumors. In tumor tissue, effector-like but not terminally differentiated exhausted CD8+ T cells increase. Consistent with the surge in tumor-specific CD8+ T cells in blood that are migration and proliferation competent, we observe a CD8-dependent and CXCR3-dependent enhancement of the abscopal effect against distant/non-irradiated tumors and find that CD8+ T cells isolated from blood after RT/anti-PD1/IL-2c triple treatment can be a rich source of tumor-specific T cells for adoptive transfers.

Abscopal Effect on Bone Metastases from Solid Tumors: A Systematic Review and Retrospective Analysis of Challenge within a Challenge

BACKGROUND

Abscopal effect (AE) describes the ability of radiotherapy (RT) to induce immune-mediated responses in nonirradiated distant metastasis. Bone represents the third most frequent site of metastasis and an immunologically favorable environment for the proliferation of cancer cells. We revised the literature, searching documented cases of AE involving bone metastases (BMs) and evaluated the incidence of AE involving BMs in patients requiring palliative RT on BMs or non-BMs treated at our department.

METHODS

Articles published in the PubMed/MEDLINE database were selected using the following search criteria: ((abscopal effect)) AND ((metastases)). Patients with BMs, who underwent performed bone scintigraphy before and at least 2-3 months after RT, were selected and screened between January 2015 and July 2022. AE was defined as an objective response according to the scan bone index for at least one nonirradiated metastasis at a distance > 10 cm from the irradiated lesion. The primary endpoint was the rate of AE on BMs.

RESULTS

Ten cases experiencing AE of BMs were identified from the literature and eight among our patients.

CONCLUSIONS

The analysis performed here suggests the use of hypofractionated radiotherapy as the only triggering factor for AE of BMs through the activation of the immune response.

Immunomodulatory effect of locoregional therapy in the tumor microenvironment

Cancer immunotherapy appears to be a promising treatment option; however, only a subset of patients with cancer responds favorably to treatment. Locoregional therapy initiates a local antitumor immune response by disrupting immunosuppressive components, releasing immunostimulatory damage-associated molecular patterns, recruiting immune effectors, and remodeling the tumor microenvironment. Many studies have shown that locoregional therapy can produce specific antitumor immunity alone; nevertheless, the effect is relatively weak and transient. Furthermore, increasing research efforts have explored the potential synergy between locoregional therapy and immunotherapy to enhance the long-term systemic antitumor immune effect and improve survival. Therefore, further research is needed into the immunomodulatory effects of locoregional therapy and immunotherapy to augment antitumor effects. This review article summarizes the key components of the tumor microenvironment, discusses the immunomodulatory role of locoregional therapy in the tumor microenvironment, and emphasizes the therapeutic potential of locoregional therapy in combination with immune checkpoint inhibitors.

Localized nuclear reaction breaks boron drug capsules loaded with immune adjuvants for cancer immunotherapy

Boron neutron capture therapy (BNCT) was clinically approved in 2020 and exhibits remarkable tumour rejection in preclinical and clinical studies. It is binary radiotherapy that may selectively deposit two deadly high-energy particles (4He and 7Li) within a cancer cell. As a radiotherapy induced by localized nuclear reaction, few studies have reported its abscopal anti-tumour effect, which has limited its further clinical applications. Here, we engineer a neutron-activated boron capsule that synergizes BNCT and controlled immune adjuvants release to provoke a potent anti-tumour immune response. This study demonstrates that boron neutron capture nuclear reaction forms considerable defects in boron capsule that augments the drug release. The following single-cell sequencing unveils the fact and mechanism that BNCT heats anti-tumour immunity. In female mice tumour models, BNCT and the controlled drug release triggered by localized nuclear reaction causes nearly complete regression of both primary and distant tumour grafts.

Avelumab for the treatment of locally advanced or metastatic Merkel cell carcinoma-A multicenter real-world experience in Israel

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive malignancy of the skin, affecting predominantly the fair-skinned older population exposed to high levels of ultraviolet light. Immune suppression is considered a significant risk factor. With the recent advances in the field of immunotherapy, the treatment paradigm for advanced MCC, traditionally based on chemotherapy, has largely shifted to anti-PD-L1 and PD-1 agents such as avelumab and pembrolizumab, respectively. However, real-world data remain sparse. The aim of this study was to assess real-world evidence of the effectiveness of avelumab in a diverse group of patients with MCC in Israel.

METHODS

The electronic databases of five university hospitals in Israel were searched for all consecutive patients with MCC treated with at least one dose of avelumab in 2018-2022. Data on baseline, disease-related, treatment-related, and outcome parameters were collected and analyzed.

RESULTS

The cohort included 62 patients of whom 22% were immune-suppressed. The overall response rate to avelumab was 59%. The median progression-free survival was 8.1 months, and the median overall survival, 23.5 months, with no differences between immune-competent and immune-suppressed patients. Treatment was well tolerated; any-grade toxicity developed in 34% of patients, and grade 3-4 toxicity, in 14%.

CONCLUSIONS

Avelumab was found to be effective and safe for the treatment of advanced MCC in a diverse group of patients, including some with immune suppression. Further studies are warranted to evaluate the optimal sequence and duration of treatment and to assess the potential role of avelumab for earlier stages of MCC.

Harnessing immunotherapy to enhance the systemic anti-tumor effects of thermosensitive liposomes

Chemotherapy plays an important role in debulking tumors in advance of surgery and/or radiotherapy, tackling residual disease, and treating metastatic disease. In recent years many promising advanced drug delivery strategies have emerged that offer more targeted delivery approaches to chemotherapy treatment. For example, thermosensitive liposome-mediated drug delivery in combination with localized mild hyperthermia can increase local drug concentrations resulting in a reduction in systemic toxicity and an improvement in local disease control. However, the majority of solid tumor-associated deaths are due to metastatic spread. A therapeutic approach focused on a localized target area harbors the risk of overlooking and undertreating potential metastatic spread. Previous studies reported systemic, albeit limited, anti-tumor effects following treatment with thermosensitive liposomal chemotherapy and localized mild hyperthermia. This work explores the systemic treatment capabilities of a thermosensitive liposome formulation of the vinca alkaloid vinorelbine in combination with mild hyperthermia in an immunocompetent murine model of rhabdomyosarcoma. This treatment approach was found to be highly effective at heated, primary tumor sites. However, it demonstrated limited anti-tumor effects in secondary, distant tumors. As a result, the addition of immune checkpoint inhibition therapy was pursued to further enhance the systemic anti-tumor effect of this treatment approach. Once combined with immune checkpoint inhibition therapy, a significant improvement in systemic treatment capability was achieved. We believe this is one of the first studies to demonstrate that a triple combination of thermosensitive liposomes, localized mild hyperthermia, and immune checkpoint inhibition therapy can enhance the systemic treatment capabilities of thermosensitive liposomes.

DNA Nanoclusters Combined with One-Shot Radiotherapy Augment Cancer Immunotherapy Efficiency

Immunotherapy shows immense promise for improving cancer treatment. Combining immunotherapy with radiotherapy provides a conspicuous advantage due to its enhanced abscopal effect. However, established immune tolerance mechanisms in the tumor microenvironment can hamper the generation of a sufficient abscopal effect. Herein, a type of DNA nanocluster (DNAnc) that is self-assembled by a CpG-ODNs-loaded Y-shaped double-stranded DNA vector based on the unique complementary base-pairing rules is designed. The unique structure of DNAnc makes it load more than ≈8125.5 ± 822.5 copies of CpG ODNs within one single nanostructure, which effectively increases resistance to nuclease degradation and elevates the efficiency of repolarizing macrophages to an M1-like phenotype. Mechanistic studies reveal that more DNAncs are endocytosed by macrophages in the cancer tissue and repolarized macrophages to elicit a robust abscopal effect with the accumulation of macrophages induced by radiotherapy, generating potent, long-term, and durable antitumor immunity for the inhibition of tumor metastasis and the prevention of tumor recurrence, which provides a novel strategy to boost cancer immunotherapy.

X-Ray Activatable Au/Ag Nanorods for Tumor Radioimmunotherapy Sensitization and Monitoring of the Therapeutic Response Using NIR-II Photoacoustic Imaging

Radioimmunotherapy (RIT) is an advanced physical therapy used to kill primary cancer cells and inhibit the growth of distant metastatic cancer cells. However, challenges remain because RIT generally has low efficacy and serious side effects, and its effects are difficult to monitor in vivo. This work reports that Au/Ag nanorods (NRs) enhance the effectiveness of RIT against cancer while allowing the therapeutic response to be monitored using activatable photoacoustic (PA) imaging in the second near-infrared region (NIR-II, 1000-1700 nm). The Au/Ag NRs can be etched using high-energy X-ray to release silver ions (Ag+ ), which promotes dendritic cell (DC) maturation, enhances T-cell activation and infiltration, and effectively inhibits primary and distant metastatic tumor growth. The survival time of metastatic tumor-bearing mice treated with Au/Ag NR-enhanced RIT is 39 days compared with 23 days in the PBS control group. Furthermore, the surface plasmon absorption intensity at 1040 nm increases fourfold after Ag+ are released from the Au/Ag NRs, allowing X-ray activatable NIR-II PA imaging to monitor the RIT response with a high signal-to-background ratio of 24.4. Au/Ag NR-based RIT has minimal side effects and shows great promise for precise cancer RIT.

Methods to assess radiation induced abscopal responses in mice

Radiotherapy (RT) can work together with the immune system to eliminate cancer. It can cause immunogenic cell death and facilitate tumor neoantigen presentation and thereby the cross-priming of tumor-specific T-lymphocytes, turning irradiated tumors into in-situ vaccines. Accumulating preclinical and clinical evidence indicates that RT in conjunction with ICB leads to systemic anti-tumor immune responses, thus stimulating interest in using ICB to overcome primary and acquired cancer resistance to radiotherapy. However, the systemic effects (abscopal effects) obtained to date are far from being acceptable for clinical translation. In this context, multiple preclinical mouse models have demonstrated that a variety of immunotherapy agents can be delivered locally to enhance antitumor immunity both in a local and systemic fashion. Using two slightly asynchronous and anatomically distant subcutaneous B16OVA tumors in syngeneic immunocompetent hosts (C57BL/6), we describe the feasibility of a local immunotherapy treatment given in combination with external beam irradiation, which exerts immune-mediated antitumor effects in mice and humans upon intratumoral delivery. With minor variations, the same technique can be easily applied to a variety of mouse transplantable tumors.

Immuno-photodynamic Therapy (IPDT): Organic Photosensitizers and Their Application in Cancer Ablation

Photosensitizer-based photodynamic therapy (PDT) has been considered as a promising modality for fighting diverse types of cancers. PDT directly inhibits local tumors by a minimally invasive strategy, but it seems to be incapable of achieving complete eradication and fails to prevent metastasis and recurrence. Recently, increasing events proved that PDT was associated with immunotherapy by triggering immunogenic cell death (ICD). Upon a specific wavelength of light irradiation, the photosensitizers will turn the surrounding oxygen molecules into cytotoxic reactive oxygen species (ROS) for killing the cancer cells. Simultaneously, the dying tumor cells release tumor-associated antigens, which could improve immunogenicity to activate immune cells. However, the progressively enhanced immunity is typically limited by the intrinsic immunosuppressive tumor microenvironment (TME). To overcome this obstacle, immuno-photodynamic therapy (IPDT) has come to be one of the most beneficial strategies, which takes advantage of PDT to stimulate the immune response and unite immunotherapy for inducing immune-OFF tumors to immune-ON ones, to achieve systemic immune response and prevent cancer recurrence. In this Perspective, we provide a review of recent advances in organic photosensitizer-based IPDT. The general process of immune responses triggered by photosensitizers (PSs) and how to enhance the antitumor immune pathway by modifying the chemical structure or conjugating with a targeting component was discussed. In addition, future perspectives and challenges associated with IPDT strategies are also discussed. We hope this Perspective could inspire more innovative ideas and provide executable strategies for future developments in the war against cancer.

Developments in Checkpoint Inhibitor Therapy for the Management of Deficient Mismatch Repair (dMMR) Rectal Cancer

Deficient mismatch repair (dMMR)/microsatellite instability-high (MSIH) colorectal cancer is resistant to conventional chemotherapy but responds to immune checkpoint inhibition (ICI). We review the standard of care in locally advanced dMMR rectal cancer with a focus on ICI. We also present a case report to highlight the treatment complexities and unique challenges of this novel treatment approach. ICI can lead to immune related adverse events (irAEs), resulting in early treatment discontinuation as well as new challenges to surveillance and surgical management. Overall, neoadjuvant ICI can lead to robust treatment responses, but its impact on durable response and organ preservation requires further study.

Bacterial outer membrane vesicle based versatile nanosystem boosts the efferocytosis blockade triggered tumor-specific immunity

Efferocytosis inhibition is emerging as an attractive strategy for antitumor immune therapy because of the subsequent leak of abundant immunogenic contents. However, the practical efficacy is seriously impeded by the immunosuppressive tumor microenvironments. Here, we construct a versatile nanosystem that can not only inhibit the efferocytosis but also boost the following antitumor immunity. MerTK inhibitor UNC2025 is loaded into the bacterial outer membrane vesicles (OMVs), which are then modified with maleimide (mU@OMVs). The prepared mU@OMVs effectively inhibits the efferocytosis by promoting the uptake while preventing the MerTK phosphorylation of tumor associated macrophages, and then captures the released antigens through forming universal thioether bonds. The obtained in situ vaccine effectively transfers to lymph nodes by virtue of the intrinsic features of OMVs, and then provokes intense immune responses that can efficiently prevent the growth, metastasis and recurrence of tumors in mice, providing a generalizable strategy for cancer immunotherapy.

Immunomodulatory effects of targeted radionuclide therapy

It is now clear that conventional radiation therapy can reinstate cell death immunogenicity. Recent preclinical data indicate that targeted radionuclide therapy that irradiate tumors at continuous low dose rate also can elicit immunostimulatory effects and represents a promising strategy to circumvent immune checkpoint inhibitor resistance. In this perspective, we discuss the accumulating preclinical and clinical data suggesting that activation of the immune system through the cGAS-STING axis and the release of extracellular vesicles by irradiated cells, participate to this antitumor immunity. This should need to be considered for adapting clinical practices to state of the art of the radiobiology and to increase targeted radionuclide therapy effectiveness.

Reactive oxygen species-powered cancer immunotherapy: Current status and challenges

Reactive oxygen species (ROS) are crucial signaling molecules that can arouse immune system. In recent decades, ROS has emerged as a unique therapeutic strategy for malignant tumors as (i) it can not only directly reduce tumor burden but also trigger immune responses by inducing immunogenic cell death (ICD); and (ii) it can be facilely generated and modulated by radiotherapy, photodynamic therapy, sonodynamic therapy and chemodynamic therapy. The anti-tumor immune responses are, however, mostly downplayed by the immunosuppressive signals and dysfunction of effector immune cells within the tumor microenvironment (TME). The past years have seen fierce developments of various strategies to power ROS-based cancer immunotherapy by e.g. combining with immune checkpoints inhibitors, tumor vaccines, and/or immunoadjuvants, which have shown to potently inhibit primary tumors, metastatic tumors, and tumor relapse with limited immune-related adverse events (irAEs). In this review, we introduce the concept of ROS-powered cancer immunotherapy, highlight the innovative strategies to boost ROS-based cancer immunotherapy, and discuss the challenges in terms of clinical translation and future perspectives.

Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure

Introduction

Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear.

Methods

This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher’s exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure.

Results

A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure.

Discussion

An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

The current understanding of the immune landscape relative to radiotherapy across tumor types

Radiotherapy is part of the standard of care treatment for a great majority of cancer patients. As a result of radiation, both tumor cells and the environment around them are affected directly by radiation, which mainly primes but also might limit the immune response. Multiple immune factors play a role in cancer progression and response to radiotherapy, including the immune tumor microenvironment and systemic immunity referred to as the immune landscape. A heterogeneous tumor microenvironment and the varying patient characteristics complicate the dynamic relationship between radiotherapy and this immune landscape. In this review, we will present the current overview of the immunological landscape in relation to radiotherapy in order to provide insight and encourage research to further improve cancer treatment. An investigation into the impact of radiation therapy on the immune landscape showed in several cancers a common pattern of immunological responses after radiation. Radiation leads to an upsurge in infiltrating T lymphocytes and the expression of programmed death ligand 1 (PD-L1) which can hint at a benefit for the patient when combined with immunotherapy. In spite of this, lymphopenia in the tumor microenvironment of 'cold' tumors or caused by radiation is considered to be an important obstacle to the patient's survival. In several cancers, a rise in the immunosuppressive populations is seen after radiation, mainly pro-tumoral M2 macrophages and myeloid-derived suppressor cells (MDSCs). As a final point, we will highlight how the radiation parameters themselves can influence the immune system and, therefore, be exploited to the advantage of the patient.

Immunotherapy for advanced or recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with high morbidity and mortality, and is prone to intra- and extrahepatic metastasis due to the anatomical and functional characteristics of the liver. Due to the complexity and high relapse rate associated with radical surgery or radiofrequency ablation, immune checkpoint inhibitors (ICIs) are increasingly being used to treat HCC. Several immunotherapeutic agents, along with their combinations, have been clinically approved to treat advanced or recurrent HCC. This review discusses the leading ICIs in practice and those currently undergoing randomized phase 1–3 trials as monotherapy or combination therapy. Furthermore, we summarize the rapidly developing alternative strategies such as chimeric antigen receptor-engineered T cell therapy and tumor vaccines. Combination therapy is a promising potential treatment option. These immunotherapies are also summarized in this review, which provides insights into the advantages, limitations, and novel angles for future research in establishing viable and alternative therapies against HCC.

Exploiting radiation immunostimulatory effects to improve glioblastoma outcome

Cancer treatment protocols depend on tumor type, localization, grade, and patient. Despite aggressive treatments, median survival of patients with Glioblastoma (GBM), the most common primary brain tumor in adults, does not exceed 18 months, and all patients eventually relapse. Thus, novel therapeutic approaches are urgently needed. Radiotherapy (RT) induces a multitude of alterations within the tumor ecosystem, ultimately modifying the degree of tumor immunogenicity at GBM relapse. The present manuscript reviews the diverse effects of RT radiotherapy on tumors, with a special focus on its immunomodulatory impact to finally discuss how RT could be exploited in GBM treatment through immunotherapy targeting. Indeed, while further experimental and clinical studies are definitively required to successfully translate preclinical results in clinical trials, current studies highlight the therapeutic potential of immunotherapy to uncover novel avenues to fight GBM.

The abscopal effect: Implications for drug discovery in autoimmunity

The emergence of novel targeted therapies and the tools that increase the stability and delivery of drugs have greatly improved treatment outcomes in autoimmune diseases (ADs). Recently-developed strategies deplete specific deleterious T- and B-cell subsets, interrupt receptor-ligand interactions, and/or inhibit the secretion or activity of inflammatory mediators linked to tissue damage. Although generally efficient, these lines of intervention have limitations, with documented cases of drug-resistance and undesired side effects. They are also difficult to apply to non-organ-specific ADs, where the trigger and effector antigens are unknown and in which autoimmune activity is widely spread throughout the body. The potential of cellular modulators that act at a distance from the affected site, by abscopal effect, as described in the case of cancer radio- and immuno-therapy might be especially efficient in the context of ADs. Future research to discover small molecule- and peptide-based treatments will need to explore potential drugs with abscopal effects that could elicit potent immune tolerance and clinical quiescence to restore quality of life of affected patients.

Biomineralized MnO2 Nanoplatforms Mediated Delivery of Immune Checkpoint Inhibitors with STING Pathway Activation to Potentiate Cancer Radio-Immunotherapy

Radiotherapy (RT), as one of the main methods in the clinical treatment of various malignant tumors, would induce systemic immunotherapeutic effects by triggering immunogenic cell death (ICD) of cancer cells. However, the antitumor immune responses produced by RT-induced ICD alone usually are not robust enough to eliminate distant tumors and thus ineffective against cancer metastases. Herein, a biomimetic mineralization method for facile synthesis of MnO₂ nanoparticles with high anti-programmed death ligand 1 (αPDL1) encapsulation efficiency (αPDL1@MnO₂) is proposed to reinforce RT-induced systemic antitumor immune responses. This therapeutic nanoplatforms-mediated RT can significantly improve the killing of tumor cells and effectively evoke ICD by overcoming hypoxia-induced radio-resistance and reprogramming the immunosuppressive tumor microenvironment (TME). Furthermore, the released Mn²⁺ ions from αPDL1@MnO₂ under acidic tumor pH can activate the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway and facilitate the dendritic cells (DCs) maturation. Meanwhile, αPDL1 released from αPDL1@MnO₂ nanoparticles would further promote the intratumoral infiltration of cytotoxic T lymphocytes (CTLs) and trigger systemic antitumor responses, resulting in a strong abscopal effect to effectively inhibit tumor metastases. Overall, the biomineralized MnO₂-based nanoplatforms offer a simple strategy for TME modulation and immune activation, which are promising for enhanced RT immunotherapy.

Trial designs and endpoints for immune therapies in multiple myeloma

Immune therapies, including CAR-T cells, bispecific antibodies, and antibody-drug conjugates, are revolutionizing the treatment of multiple myeloma. In this review, we discuss clinical trial design considerations relevant to immune therapies. We first examine issues pertinent to specific populations, including elderly, patients with renal impairment, high-risk/extramedullary disease, and prior immune therapies. We then highlight trial designs to optimize the selection of dose and schedule, explore rational combination therapies based on preclinical data, and evaluate the nuances of commonly used endpoints. By exploiting their pharmacokinetic/pharmacodynamic profiles and utilizing novel translational insights, we can optimize the use of immune therapies in multiple myeloma.

Antigen discovery for the development of cancer immunotherapy

Central to successful cancer immunotherapy is effective T cell antitumor immunity. Multiple targeted immunotherapies engineered to invigorate T cell-driven antitumor immunity rely on identifying the repertoire of T cell antigens expressed on the tumor cell surface. Mass spectrometry-based survey of such antigens ("immunopeptidomics") combined with other omics platforms and computational algorithms has been instrumental in identifying and quantifying tumor-derived T cell antigens. In this review, we discuss the types of tumor antigens that have emerged for targeted cancer immunotherapy and the immunopeptidomics methods that are central in MHC peptide identification and quantification. We provide an overview of the strength and limitations of mass spectrometry-driven approaches and how they have been integrated with other technologies to discover targetable T cell antigens for cancer immunotherapy. We highlight some of the emerging cancer immunotherapies that successfully capitalized on immunopeptidomics, their challenges, and mass spectrometry-based strategies that can support their development.

Radiotherapy Induces Innate Immune Responses in Patients Treated for Prostate Cancers

PURPOSE

Radiotherapy is a curative therapeutic modality used to treat cancers as a single agent or in combination with surgery and chemotherapy. Advanced radiotherapy technologies enable treatment with large fractions and highly conformal radiation doses to effect free-radical damage to cellular DNA leading to cell-cycle arrest, cell death, and innate immune response (IIR) stimulation.

EXPERIMENTAL DESIGN

To understand systemic clinical responses after radiation exposure, proteomic and metabolomic analyses were performed on plasma obtained from patients with cancer at intervals after prostate stereotactic body radiotherapy. Pathway and multivariate analyses were used to delineate molecular alterations following radiotherapy and its correlation with clinical outcomes.

RESULTS

DNA damage response increased within the first hour after treatment and returned to baseline by 1 month. IIR signaling also increased within 1 hour of treatment but persisted for up to 3 months thereafter. Furthermore, robust IIR and metabolite elevations, consistent with an early proinflammatory M1-mediated innate immune activation, were observed in patients in remission, whereas patients experiencing prostate serum antigen-determined disease progression demonstrated less robust immune responses and M2-mediated metabolite elevations.

CONCLUSIONS

To our knowledge, these data are the first report of longitudinal proteomic and metabolomic molecular responses in patients after radiotherapy for cancers. The data supports innate immune activation as a critical clinical response of patients receiving radiotherapy for prostate cancer. Furthermore, we propose that the observed IIR may be generalized to the treatment of other cancer types, potentially informing multidisciplinary therapeutic strategies for cancer treatment.

Biodegradable nanomaterials for diagnosis and therapy of tumors

Although degradable nanomaterials have been widely designed and applied for cancer bioimaging and various cancer treatments, few reviews of biodegradable nanomaterials have been reported. Herein, we have summarized the representative research advances of biodegradable nanomaterials with respect to the mechanism of degradation and their application in tumor imaging and therapy. First, four kinds of tumor microenvironment (TME) responsive degradation are presented, including pH, glutathione (GSH), hypoxia and matrix metalloproteinase (MMP) responsive degradation. Second, external stimulation degradation is summarized briefly. Next, we have outlined the applications of nanomaterials in bioimaging. Finally, we have focused on some typical examples of biodegradable nanomaterials in radiotherapy (RT), photothermal therapy (PTT), starvation therapy, photodynamic therapy (PDT), chemotherapy, chemodynamic therapy (CDT), sonodynamic therapy (SDT), gene therapy, immunotherapy and combination therapy.

On target methods to induce abscopal phenomenon for Off-Target effects: From happenstance to happenings

Although the "abscopal phenomenon" has been described several decades ago, this phenomenon lately has been obtaining momentous traction with the dawn of immune-based therapies. There has been increased cross talk among radiation oncologists, oncologists and immunologists and consequently a surge in the number of prospective clinical trials. This must be coupled with translation work from these clinical trials to aid in eventual identification of patients who may benefit. Abscopal effects may be induced by local and systemic methods, conventional radiotherapy, particle radiation, radionucleotide methods, cryoablation and brachytherapy. These approaches have all been reported to be stimulate abscopal effect. Immune induction by immune checkpoint therapy, immune adjuvants, cellular therapy including CAR and NK cell therapies may generate systemic abscopal response. With increasing recognition of this effect, there remains a lot of work to explore the modalities of inducing abscopal responses and ultimate prediction or prognostication on stratifying who may benefit. Ultimately, there is an urgent need for prospective studies and data to tease apart which one of these modalities can be applied to the appropriate candidate, to the appropriate cancer at the appropriate setting. This review seeks to elucidate readers on the different modalities of radiation, systemic therapies and other techniques rarely explored to potentiate the abscopal effect from a mere coincidence to a finite occurrence.

Current Strategies for Modulating Tumor-Associated Macrophages with Biomaterials in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related deaths in the world. However, there are currently few clinical diagnosis and treatment options available, and there is an urgent need for novel effective approaches. More research is being undertaken on immune-associated cells in the microenvironment because they play a critical role in the initiation and development of HCC. Macrophages are specialized phagocytes and antigen-presenting cells (APCs) that not only directly phagocytose and eliminate tumor cells, but also present tumor-specific antigens to T cells and initiate anticancer adaptive immunity. However, the more abundant M2-phenotype tumor-associated macrophages (TAMs) at tumor sites promote tumor evasion of immune surveillance, accelerate tumor progression, and suppress tumor-specific T-cell immune responses. Despite the great success in modulating macrophages, there are still many challenges and obstacles. Biomaterials not only target macrophages, but also modulate macrophages to enhance tumor treatment. This review systematically summarizes the regulation of tumor-associated macrophages by biomaterials, which has implications for the immunotherapy of HCC.

Nrf2 silencing amplifies DNA photooxidative damage to activate the STING pathway for synergistic tumor immunotherapy

Photodynamic therapy (PDT)-mediated antitumor immune response depends on oxidative stress intensity and subsequent immunogenic cell death (ICD) in tumor cells, yet the inherent antioxidant system restricts reactive oxygen species (ROS)-associated oxidative damage, which is highly correlated with the upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) and the downstream products, such as glutathione (GSH). Herein, to overcome this dilemma, we designed a versatile nanoadjuvant (RI@Z-P) to enhance the sensitivity of tumor cells to oxidative stress via Nrf2-specific small interfering RNA (siNrf2). The constructed RI@Z-P could significantly amplify photooxidative stress and achieve robust DNA oxidative damage, activating the stimulator of interferon genes (STING)-dependent immune-sensing to produce interferon-β (IFN-β). Additionally, RI@Z-P together with laser irradiation reinforced tumor immunogenicity by exposing or releasing damage-associated molecular patterns (DAMPs), showing the prominent adjuvant effect for promoting dendritic cell (DC) maturation and T-lymphocyte activation and even alleviating the immunosuppressive microenvironment to some extent.

Design of a Tumor Binding GMCSF as Intratumoral Immunotherapy of Solid Tumors

Next-generation cancer immunotherapies may utilize immunostimulants to selectively activate the host immune system against tumor cells. Checkpoint inhibitors (CPIs) like anti-PD1/PDL-1 that inhibit immunosuppression have shown unprecedented success but are only effective in the 20-30% of patients that possess an already "hot" (immunogenic) tumor. In this regard, intratumoral (IT) injection of immunostimulants is a promising approach since they can work synergistically with CPIs to overcome the resistance to immunotherapies by inducing immune stimulation in the tumor. One such immunostimulant is granulocyte macrophage-colony-stimulating factor (GMCSF) that functions by recruiting and activating antigen-presenting cells (dendritic cells) in the tumor, thereby initiating anti-tumor immune responses. However, key problems with GMCSF are lack of efficacy and the risk of systemic toxicity caused by the leakage of GMCSF from the tumor tissue. We have designed tumor-retentive versions of GMCSF that are safe yet potent immunostimulants for the local treatment of solid tumors. The engineered GMCSFs (eGMCSF) were synthesized by recombinantly fusing tumor-ECM (extracellular matrix) binding peptides to GMCSF. The eGMCSFs exhibited enhanced tumor binding and potent immunological activity in vitro and in vivo. Upon IT administration, the tumor-retentive eGMCSFs persisted in the tumor, thereby alleviating systemic toxicity, and elicited localized immune activation to effectively turn an unresponsive immunologically "cold" tumor "hot".

The optimization of postoperative radiotherapy in de novo stage IV breast cancer: evidence from real-world data to personalize treatment decisions

Prolonged survival of patients with stage IV breast cancer could change the role of radiotherapy for local control of breast primary, but its survival benefit remains unclear. Our aim is to investigate the survival benefit of radiotherapy in de novo stage IV breast cancer. Stage IV breast cancer patients who received breast surgery and have survived 12 months after diagnosis (landmark analysis) were included in the study from 2010 to 2015 of the National Cancer DataBase. Multivariable Cox models and a propensity score matching were used to control for confounding effects. Of 11,850 patients, 3629 (30.6%) underwent postoperative radiotherapy to breast or chest wall and 8221 (69.4%) did not. In multivariable analysis adjusting for multiple prognostic variables, postoperative radiotherapy was significantly associated with better survival (hazard ratio [HR] 0.74, 95% confidence interval [95%CI] 0.69-0.80; P < 0.001). Radiotherapy was associated with improved survival in patients with bone (P < 0.001) or lung metastasis (P = 0.014), but not in patients with liver (P = 0.549) or brain metastasis (P = 0.407). Radiotherapy was also associated with improved survival in patients with one (P < 0.001) or two metastatic sites (P = 0.028), but not in patients with three or more metastatic sites (P = 0.916). The survival impact of radiotherapy did not differ among subtypes. The results of survival analysis in the propensity score-matched sub-cohort were precisely consistent with those of multivariable analysis. These real-world data show that postoperative radiotherapy might improve overall survival for de novo Stage IV breast cancer with bone or lung metastasis, regardless of subtypes.

Novel strategies for tumor radiosensitization mediated by multifunctional gold-based nanomaterials

Radiotherapy (RT) is one of the most effective and commonly used cancer treatments for malignant tumors. However, the existing radiosensitizers have a lot of side effects and poor efficacy, which limits the curative effect and further application of radiotherapy. In recent years, emerging nanomaterials have shown unique advantages in enhancing radiosensitization. In particular, gold-based nanomaterials, with high X-ray attenuation capacity, good biocompatibility, and promising chemical, electronic and optical properties, have become a new type of radiotherapy sensitizer. In addition, gold-based nanomaterials can be used as a carrier to load a variety of drugs and immunosuppressants; in particular, its photothermal therapy, photodynamic therapy and multi-mode imaging functions aid in providing excellent therapeutic effect in coordination with RT. Recently, many novel strategies of radiosensitization mediated by multifunctional gold-based nanomaterials have been reported, which provides a new idea for improving the efficacy and reducing the side effects of RT. In this review, we systematically summarize the recent progress of various new gold-based nanomaterials that mediate radiosensitization and describe the mechanism. We further discuss the challenges and prospects in the field. It is hoped that this review will help researchers understand the latest progress of gold-based nanomaterials for radiosensitization, and encourage people to optimize the existing methods or explore novel approaches for radiotherapy.

Exploring new frontiers in prostate cancer research: Report from the 2022 Coffey-Holden prostate cancer academy meeting

INTRODUCTION

The 2022 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Exploring New Frontiers in Prostate Cancer Research," was held from June 23 to 26, 2022, at the University of California, Los Angeles, Luskin Conference Center, in Los Angeles, CA.

METHODS

The CHPCA Meeting is an annual discussion-oriented scientific conference organized by the Prostate Cancer Foundation, that focuses on emerging and next-step topics deemed critical for making the next major advances in prostate cancer research and clinical care. The 2022 CHPCA Meeting included 35 talks over 10 sessions and was attended by 73 academic investigators.

RESULTS

Major topic areas discussed at the meeting included: prostate cancer diversity and disparities, the impact of social determinants on research and patient outcomes, leveraging real-world and retrospective data, development of artificial intelligence biomarkers, androgen receptor (AR) signaling biology and new strategies for targeting AR, features of homologous recombination deficient prostate cancer, and future directions in immunotherapy and nuclear theranostics.

DISCUSSION

This article summarizes the scientific presentations from the 2022 CHPCA Meeting, with the goal that dissemination of this knowledge will contribute to furthering global prostate cancer research efforts.