Chemotherapy and radiotherapy: cryptic anticancer vaccines

In Situ Cancer Vaccines: Redefining Immune Activation in the Tumor Microenvironment

Cancer is one of the leading causes of mortality worldwide. Nanomedicines have significantly improved life expectancy and survival rates for cancer patients in current standard care. However, recurrence of cancer due to metastasis remains a significant challenge. Vaccines can provide long-term protection and are ideal for preventing bacterial and viral infections. Cancer vaccines, however, have shown limited therapeutic efficacy and raised safety concerns despite extensive research. Cancer vaccines target and stimulate responses against tumor-specific antigens and have demonstrated great potential for cancer treatment in preclinical studies. However, tumor-associated immunosuppression and immune tolerance driven by immunoediting pose significant challenges for vaccine design. In situ vaccination represents an alternative approach to traditional cancer vaccines. This strategy involves the intratumoral administration of immunostimulants to modulate the growth and differentiation of innate immune cells, such as dendritic cells, macrophages, and neutrophils, and restore T-cell activity. Currently approved in situ vaccines, such as T-VEC, have demonstrated clinical promise, while ongoing clinical trials continue to explore novel strategies for broader efficacy. Despite these advancements, failures in vaccine research highlight the need to address tumor-associated immune suppression and immune escape mechanisms. In situ vaccination strategies combine innate and adaptive immune stimulation, leveraging tumor-associated antigens to activate dendritic cells and cross-prime CD8+ T cells. Various vaccine modalities, such as nucleotide-based vaccines (e.g., RNA and DNA vaccines), peptide-based vaccines, and cell-based vaccines (including dendritic, T-cell, and B-cell approaches), show significant potential. Plant-based viral approaches, including cowpea mosaic virus and Newcastle disease virus, further expand the toolkit for in situ vaccination. Therapeutic modalities such as chemotherapy, radiation, photodynamic therapy, photothermal therapy, and Checkpoint blockade inhibitors contribute to enhanced antigen presentation and immune activation. Adjuvants like CpG-ODN and PRR agonists further enhance immune modulation and vaccine efficacy. The advantages of in situ vaccination include patient specificity, personalization, minimized antigen immune escape, and reduced logistical costs. However, significant barriers such as tumor heterogeneity, immune evasion, and logistical challenges remain. This review explores strategies for developing potent cancer vaccines, examines ongoing clinical trials, evaluates immune stimulation methods, and discusses prospects for advancing in situ cancer vaccination.

The influence of the microbiome on radiotherapy and DNA damage responses

Colorectal cancer (CRC) is one of the most prevalent cancers in terms of diagnosis and mortality. Radiotherapy (RT) remains a mainstay of CRC therapy. As RT relies on DNA damage to promote tumor cell death, the activity of cellular DNA damage repair pathways can modulate cancer sensitivity to therapy. The gut microbiome has been shown to influence intestinal health and is independently associated with CRC development, treatment responses and outcomes. The microbiome can also modulate responses to CRC RT through various mechanisms such as community structure, toxins and metabolites. In this review we explore the use of RT in the treatment of CRC and the molecular factors that influence treatment outcomes. We also discuss how the microbiome can promote radiosensitivity versus radioprotection to modulate RT outcomes in CRC. Understanding the molecular interaction between the microbiome and DNA repair pathways can assist with predicting responses to RT. Once described, these connections between the microbiome and RT response can also be used to identify actionable targets for therapeutic development.

The role of microalgal extracts and their combination with tamoxifen in the modulation of breast cancer immunotherapy (Review)

Cancer is one of the deadliest health menaces humans have ever witnessed. It is a leading cause of human mortality. Today, it remains a main leading cause of death globally primarily due to lifestyle changes and population ageing. A total of ~12.7 million cancer cases and 7.6 million cancer deaths were reported in 2008. In developing countries, cancer accounted for 56% of cases and 64% of deaths. Tamoxifen is the most reputable and recommended specific oestrogen receptor modulator drug used for the treatment of breast cancer. In the past decade, algae have demonstrated remarkable potency for advanced life applications. They can remain a focus of interest in the coming decades because they are one of the most diverse organisms in the entire ecosystem with immense bio nutritional benefits. Algae and their extracts play a pivotal role in the pharmaceutical industry as bioactive compounds and new drugs and nutraceutical industry as probiotics and antioxidants. However, a broad range of the health benefits of these organisms remains to be explored. The present review highlights the applications and co-application of microalgal crude extracts with tamoxifen for breast cancer immunotherapy. Given that recent studies have suggested that tamoxifen is an essential and primary treatment for breast cancer, the present review focused on the identification of a new treatment approach involving the co-application of tamoxifen and microalgal extracts to provide promising anticancer activity with few side effects on normal cells. The present review includes a general background and blueprint for the use of microalgal extracts as potential and affordable treatments or adjuncts for breast cancer management.

Construction and Evaluation of Nomogram for Hematological Indicators to Predict Pathological Response after Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

OBJECTIVE

A retrospective study was conducted by developing prediction models to evaluate the association between hematological indexes, their changes during neoadjuvant chemoradiotherapy (NCRT), and tumor pathological response in patients with locally advanced rectal cancer.

METHODS

The clinical data of 202 patients who received NCRT and radical surgery in Sichuan Cancer Hospital were retrospectively analyzed. Univariate and logistic multivariate regression analyses were used to identify hematological indexes with predictive significance. The independent risk factors were imported into the R software, and a nomogram prediction model was developed. The bootstrap method and ROC curve were used to evaluate the discriminative degree of the model.

RESULTS

Univariate analysis demonstrated age, tumor diameter, preoperative T, distance from tumor to the anal verge, CEA before NCRT, preoperative CEA, lymphocyte changes, platelet changes, and pathology of rectal cancer after NCRT were associated. Multivariate analysis demonstrated that age, tumor distance from the anus, preoperative CEA, lymphocyte changes, and platelet changes were independent risk factors. The independent risk factors were imported into the R software to construct a nomogram model. The area under the ROC was 0.76, and the slope of the calibration curve of the nomogram was close to 1.

CONCLUSION

A low preoperative CEA level, a young age, a high tumor from the anal verge, the maintenance of circulating lymphocyte level, and a decreased platelet level after NCRT are important factors for favorable outcomes after NCRT. Developing a nomogram prediction model with good discrimination and consistency can provide some guidance for predicting pathological responses after NCRT.

Effect of tumor-infiltrating lymphocytes depending on the presence of postmastectomy radiotherapy on the prognosis in pT1-2N1M0 breast cancer

Background

Currently, it remains unclear regarding the association between tumor-infiltrating lymphocytes (TILs) and the efficacy of postoperative radiotherapy in primary tumors. Here we attempted to investigate the effect of TILs depending on the presence of postmastectomy radiotherapy (PMRT) on the prognosis in pT1-2N1M0 breast cancer.

Methods

The clinical data of pT1-2N1M0 breast cancer patients undergoing mastectomy and axillary lymph node dissection were retrospectively analyzed. The effect of TILs on the prognosis was assessed based on the infiltration degree (low: TILs ≤10%, high: TILs >10%), and then the prognosis of patients with low and high infiltration of TILs was analyzed based on presence or absence of PMRT.

Results

Totally 213 patients were eligible for the study, including 162 cases of low infiltration and 51 of high infiltration. High-infiltration patients tended to be ER/PR-negative, HER2-positive, and have high histological grade. The infiltration in triple-negative and HER2-positive subtypes was higher compared with Luminal A subtype. Regarding local-regional recurrence-free survival, recurrence-free survival, and overall survival (OS) rates, the differences were all inapparent whether in high- and low-infiltration patients or in high-infiltration patients with/without PMRT. Compared with those without PMRT, low-infiltration patients with PMRT showed a significantly increased OS rate (92.8% vs. 80.0%, p=0.023). Multivariate analysis further confirmed PMRT as an independent predicator of OS in low-infiltration patients (HR: 0.228, 95%CI: 0.081-0.644, p=0.005).

Conclusion

High infiltration of TILs in pT1-2N1M0 breast cancer may be associated with clinicopathological factors. Low-infiltration patients, but not high-infiltration patients, may derive survival benefits from PMRT.

Involvement of inflammasomes in tumor microenvironment and tumor therapies

Inflammasomes are macromolecular platforms formed in response to damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns, whose formation would cause maturation of interleukin-1 (IL-1) family members and gasdermin D (GSDMD), leading to IL-1 secretion and pyroptosis respectively. Several kinds of inflammasomes detecting different types of dangers have been found. The activation of inflammasomes is regulated at both transcription and posttranscription levels, which is crucial in protecting the host from infections and sterile insults. Present findings have illustrated that inflammasomes are involved in not only infection but also the pathology of tumors implying an important link between inflammation and tumor development. Generally, inflammasomes participate in tumorigenesis, cell death, metastasis, immune evasion, chemotherapy, target therapy, and radiotherapy. Inflammasome components are upregulated in some tumors, and inflammasomes can be activated in cancer cells and other stromal cells by DAMPs, chemotherapy agents, and radiation. In some cases, inflammasomes inhibit tumor progression by initiating GSDMD-mediated pyroptosis in cancer cells and stimulating IL-1 signal-mediated anti-tumor immunity. However, IL-1 signal recruits immunosuppressive cell subsets in other cases. We discuss the conflicting results and propose some possible explanations. Additionally, we also summarize interventions targeting inflammasome pathways in both preclinical and clinical stages. Interventions targeting inflammasomes are promising for immunotherapy and combination therapy.

Analysis of the Occurrence of Predicative Factors of Chronic Fatigue in Female Patients with Cancer of the Reproductive Organs with Respect to Stage of Treatment

The aim of this study was to search for mechanisms contributing to cancer-related fatigue in patients with gynecologic cancer. The study involved 51 women with advanced endometrial cancer and ovarian cancer undergoing chemotherapy. Data were gathered at four points in time. After giving consent, each of the women had their blood drawn several times (before surgery and the first, third, and sixth cycle of chemotherapy) to determine serum levels of pro- and anti-inflammatory cytokines. Empirical data were collected using the MFSI-SF and an original questionnaire. Cancer-related fatigue (CRF) was present at every stage of treatment, but the highest mean scores were noted before cytoreductive surgery (8.745 ± 4.599), and before the sixth cycle of chemotherapy (9.667 ± 4.493). Statistically significant relationships were found between IL-1α, IL-1β, IL-2, Il-6, and IL-10 and fatigue at different stages of treatment. Older age and an above-normal BMI were the major prerequisite factors for the occurrence of fatigue in female oncological patients. The analysis of changes in cytokine levels and the severity of fatigue may be used to improve our understanding of cancer-related fatigue, and to take action to alleviate the obtrusive symptoms experienced by female patients with cancer of the reproductive organs.

Local administration of large surface area microparticle docetaxel to solid carcinomas induces direct cytotoxicity and immune-mediated tumoricidal effects: preclinical and clinical studies

This report describes local administration of large surface area microparticle docetaxel (LSAM-DTX: ~ 3.5- to 7.5-µm-sized particles with high relative surface area) in preclinical oncology models and in a clinical trial in urothelial carcinoma. Reductions in tumor volumes were found following intratumoral (IT) injection of LSAM-DTX into human urologic carcinoma cell lines and syngeneic murine renal and breast cancer cell lines. Compared to IT injections of docetaxel solution typically administered intravenously, IT LSAM-DTX results in 40-fold more docetaxel retained within the tumor. The long residence time of LSAM-DTX within the tumor acts as a drug depot, allowing for continuous release of docetaxel, exposing tumor cells to high, therapeutic levels of chemotherapeutic for several weeks. Local LSAM-DTX results in tumoricidal effects at the site of deposition as well as in distant tumors, and IT LSAM-DTX in combination with immune checkpoint inhibitor therapy reduces or eliminates metastatic spread. Tumoricidal effects of local LSAM-DTX are accompanied by immunomodulation including increases in innate and adaptive immune cells in the tumor microenvironment and peripheral blood. Encouraging clinical results indicate that local administration of LSAM-DTX may provide therapeutic benefits for non-muscle invasive bladder cancer and muscle invasive bladder cancer patients; treatments were well-tolerated with few local and systemic adverse events and negligible systemic docetaxel exposure. Results of preclinical and clinical investigations summarized here indicate that local administration of LSAM-DTX may augment tumor response to systemically administered chemotherapy, targeted therapy, or immunotherapy without contributing to systemic toxicity.

Lactate in the tumor microenvironment: A rising star for targeted tumor therapy

Metabolic reprogramming is one of fourteen hallmarks of tumor cells, among which aerobic glycolysis, often known as the "Warburg effect," is essential to the fast proliferation and aggressive metastasis of tumor cells. Lactate, on the other hand, as a ubiquitous molecule in the tumor microenvironment (TME), is generated primarily by tumor cells undergoing glycolysis. To prevent intracellular acidification, malignant cells often remove lactate along with H⁺, yet the acidification of TME is inevitable. Not only does the highly concentrated lactate within the TME serve as a substrate to supply energy to the malignant cells, but it also works as a signal to activate multiple pathways that enhance tumor metastasis and invasion, intratumoral angiogenesis, as well as immune escape. In this review, we aim to discuss the latest findings on lactate metabolism in tumor cells, particularly the capacity of extracellular lactate to influence cells in the tumor microenvironment. In addition, we examine current treatment techniques employing existing medications that target and interfere with lactate generation and transport in cancer therapy. New research shows that targeting lactate metabolism, lactate-regulated cells, and lactate action pathways are viable cancer therapy strategies.

Arsenic trioxide elicits prophylactic and therapeutic immune responses against solid tumors by inducing necroptosis and ferroptosis

Boosting tumor immunosurveillance with vaccines has been proven to be a feasible and cost-effective strategy to fight cancer. Although major breakthroughs have been achieved in preventative tumor vaccines targeting oncogenic viruses, limited advances have been made in curative vaccines for virus-irrelevant malignancies. Accumulating evidence suggests that preconditioning tumor cells with certain cytotoxic drugs can generate whole-cell tumor vaccines with strong prophylactic activities. However, the immunogenicity of these vaccines is not sufficient to restrain the outgrowth of existing tumors. In this study, we identified arsenic trioxide (ATO) as a wide-spectrum cytotoxic and highly immunogenic drug through multiparameter screening. ATO preconditioning could generate whole-cell tumor vaccines with potent antineoplastic effects in both prophylactic and therapeutic settings. The tumor-preventive or tumor-suppressive benefits of these vaccines relied on CD8+ T cells and type I and II interferon signaling and could be linked to the release of immunostimulatory danger molecules. Unexpectedly, following ATO-induced oxidative stress, multiple cell death pathways were activated, including autophagy, apoptosis, necroptosis, and ferroptosis. CRISPR‒Cas9-mediated knockout of cell death executors revealed that the absence of Rip3, Mlkl, or Acsl4 largely abolished the efficacy of ATO-based prophylactic and therapeutic cancer vaccines. This therapeutic failure could be rescued by coadministration of danger molecule analogs. In addition, PD-1 blockade synergistically improved the therapeutic efficacy of ATO-based cancer vaccines by augmenting local IFN-γ production.

Radiovaccination Strategy for Cancer Treatment Integrating Photodynamic Therapy-Generated Vaccines with Radiotherapy

Therapeutic cancer vaccines have become firmly established as a reliable and proficient form of tumor immunotherapy. They represent a promising approach for substantial advancements in the successful treatment of malignant diseases. One attractive vaccine strategy is using, as the vaccine material, the whole tumor cells treated ex vivo by rapid tumor ablation therapies that instigate stress signaling responses culminating in immunogenic cell death (ICD). One such treatment is photodynamic therapy (PDT). The underlying mechanisms and critical elements responsible for the potency of these vaccines are discussed in this review. Radiotherapy has emerged as a suitable component for the combined therapy protocols with the vaccines. Arguments and prospects for optimizing tumor control using a radiovaccination strategy involving X-ray irradiation plus PDT vaccines are presented, together with the findings supporting its validity.

Harnessing the Immunogenic Potential of Gold Nanoparticle-Based Platforms as a Therapeutic Strategy in Breast Cancer Immunotherapy: A Mini Review

Breast cancer remains the most common malignancy among women worldwide. Although the implementation of mammography has dramatically increased the early detection rate, conventional treatments like chemotherapy, radiation therapy, and surgery, have significantly improved the prognosis for breast cancer patients. However, about a third of treated breast cancer patients are known to suffer from disease recurrences and progression to metastasis. Immunotherapy has recently gained traction due to its ability to establish long-term immune surveillance, and response for the prevention of disease recurrence and extension of patient survival. Current research findings have revealed that gold nanoparticles can enhance the safety and efficacy of cancer immunotherapy, through their unique intrinsic properties of good biocompatibility, durability, convenient surface modification, as well as enhanced permeability and retention effect. Gold nanoparticles are also able to induce innate immune responses through the process of immunogenic cell death, which can lead to the establishment of lasting adaptive immunity. As such gold nanoparticles are considered as good candidates for next generation immunotherapeutic strategies. This mini review gives an overview of gold nanoparticles and their potential applications in breast cancer immunotherapeutic strategies.

Target-Based Radiosensitization Strategies: Concepts and Companion Animal Model Outlook

External beam radiotherapy is indicated in approximately 50-60% of human cancer patients. The prescribed dose of ionizing radiation that can be delivered to a tumor is determined by the sensitivity of the normal surrounding tissues. Despite dose intensification provided by highly conformal radiotherapy, durable locoregional tumor control remains a clinical barrier for recalcitrant tumor histologies, and contributes to cancer morbidity and mortality. Development of target-based radiosensitization strategies that selectively sensitizes tumor tissue to ionizing radiation is expected to improve radiotherapy efficacy. While exploration of radiosensitization strategies has vastly expanded with technological advances permitting the precise and conformal delivery of radiation, maximal clinical benefit derived from radiotherapy will require complementary discoveries that exploit molecularly-based vulnerabilities of tumor cells, as well as the assessment of investigational radiotherapy strategies in animal models that faithfully recapitulate radiobiologic responses of human cancers. To address these requirements, the purpose of this review is to underscore current and emerging concepts of molecularly targeted radiosensitizing strategies and highlight the utility of companion animal models for improving the predictive value of radiotherapy investigations.

Can pretreatment blood biomarkers predict pathological response to neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer?

Aims: To investigate the value of previously described pretreatment hematological and biochemical biomarkers as predictors of pathological response. Methods: The authors performed a retrospective analysis of 191 patients with locally advanced rectal cancer who underwent long-course neoadjuvant chemoradiotherapy at two Portuguese centers. The authors performed logistic regression analysis to search for predictive markers of pathological complete and good response. Results: High platelet-neutrophil index (p = 0.042) and clinical tumor stage >2 (p = 0.015) were predictive of poor response. None of the analyzed biomarkers predicted pathological complete response in this study. Conclusion: A high platelet-neutrophil index before neoadjuvant chemoradiotherapy could help predict poorer pathological response in patients with locally advanced rectal cancer. However, no other blood biomarker predicted incomplete or poor response in this study.

Abscopal Effect and Drug-Induced Xenogenization: A Strategic Alliance in Cancer Treatment?

The current state of cancer treatment is still far from being satisfactory considering the strong impairment of patients' quality of life and the high lethality of malignant diseases. Therefore, it is critical for innovative approaches to be tested in the near future. In view of the crucial role that is played by tumor immunity, the present review provides essential information on the immune-mediated effects potentially generated by the interplay between ionizing radiation and cytotoxic antitumor agents when interacting with target malignant cells. Therefore, the radiation-dependent abscopal effect (i.e., a biological effect of ionizing radiation that occurs outside the irradiated field), the influence of cancer chemotherapy on the antigenic pattern of target neoplastic cells, and the immunogenic cell death (ICD) caused by anticancer agents are the main topics of this presentation. It is widely accepted that tumor immunity plays a fundamental role in generating an abscopal effect and that anticancer drugs can profoundly influence not only the host immune responses, but also the immunogenic pattern of malignant cells. Remarkably, several anticancer drugs impact both the abscopal effect and ICD. In addition, certain classes of anticancer agents are able to amplify already expressed tumor-associated antigens (TAA). More importantly, other drugs, especially triazenes, induce the appearance of new tumor neoantigens (TNA), a phenomenon that we termed drug-induced xenogenization (DIX). The adoption of the abscopal effect is proposed as a potential therapeutic modality when properly applied concomitantly with drug-induced increase in tumor cell immunogenicity and ICD. Although little to no preclinical or clinical studies are presently available on this subject, we discuss this issue in terms of potential mechanisms and therapeutic benefits. Upcoming investigations are aimed at evaluating how chemical anticancer drugs, radiation, and immunotherapies are interacting and cooperate in evoking the abscopal effect, tumor xenogenization and ICD, paving the way for new and possibly successful approaches in cancer therapy.

Autologous Dendritic Cells in Combination With Chemotherapy Restore Responsiveness of T Cells in Breast Cancer Patients: A Single-Arm Phase I/II Trial

Introduction

Animal studies and preclinical studies in cancer patients suggest that the induction of immunogenic cell death (ICD) by neoadjuvant chemotherapy with doxorubicin and cyclophosphamide (NAC-AC) recovers the functional performance of the immune system. This could favor immunotherapy schemes such as the administration of antigen-free autologous dendritic cells (DCs) in combination with NAC-AC to profit as cryptic vaccine immunogenicity of treated tumors.

Objective

To explore the safety and immunogenicity of autologous antigen-free DCs administered to breast cancer patients (BCPs) in combination with NAC-AC.

Materials and Methods

A phase I/II cohort clinical trial was performed with 20 BCPs treated with NAC-AC [nine who received DCs and 11 who did not (control group)]. The occurrence of adverse effects and the functional performance of lymphocytes from BCPs before and after four cycles of NAC-AC receiving DCs or not were assessed using flow cytometry and compared with that from healthy donors (HDs). Flow cytometry analysis using manual and automated algorithms led us to examine functional performance and frequency of different lymphocyte compartments in response to a stimulus in vitro. This study was registered at clinicaltrials.gov (NCT03450044).

Results

No grade II or higher adverse effects were observed associated with the transfer of DCs to patients during NAC-AC. Interestingly, in response to the in vitro stimulation, deficient phosphorylation of Zap70 and AKT proteins observed before chemotherapy in most patients’ CD4 T cells significantly recovered after NAC-AC only in patients who received DCs.

Conclusions

The transfer of autologous DCs in combination with NAC-AC in BCPs is a safe procedure. That, in BCPs, the administration of DCs in combination with NAC-AC favors the recovery of the functional capacity of T cells suggests that this combination may potentiate the adjuvant effect of ICD induced by NAC-AC on T cells and, hence, potentiate the immunogenicity of tumors as cryptic vaccines.

Peripheral blood CD45RO+T cells is a predictor of the effectiveness of neoadjuvant chemoradiotherapy in locally advanced rectal cancer

To investigate the relationship between the changes in circulating CD45RO+T lymphocyte subsets following neoadjuvant therapy for rectal cancer in patients with locally advanced rectal cancer.The clinicopathological data of 185 patients with rectal cancer who received neoadjuvant therapy in the General Surgery Department of Beijing Chaoyang Hospital affiliated to Capital Medical University from June 2015 to June 2017 were analyzed. Venous blood samples were collected 1 week before neoadjuvant therapy and 1 week before surgery, and the expression of CD45RO+T was detected by flow cytometry. The receiver operating characteristic curve analysis was used to determine the optimal cut-off point of CD45RO+ratio. Log-rank test and multivariate Cox regression were used to analyze the overall survival rate (OS) and disease-free survival rate (DFS) associated with CD45RO+ratio.Circulating CD45RO+ratio of 1.07 was determined as the optimal cut-off point and CD45RO+ratio-high was associated with lower tumor regression grade grading (P = .031), T stage (P = .001), and tumor node metastasis (TNM) stage (P = .012). The 3-year DFS and OS rate in the CD45RO+ratio-high group was significantly higher than that in the CD45RO+ratio-low group (89.2% vs 60.1%, P<.001; 94.4% vs 73.2%, P<.001). The multivariate Cox analysis revealed that elevated CD45RO+ratio was an independent factor for better DFS (OR, 0.339; 95% CI, 0.153-0.752; P = .008) and OS (OR, 0.244; 95% CI,0.082-0.726; P = .011).Circulating CD45RO+ratio could predict the tumor regression grade of neoadjuvant therapy for rectal cancer, as well as long-term prognosis. These findings could be used to stratify patients and develop alternative strategies for adjuvant therapy.

Optimizing radiotherapy plans for cancer treatment with Tensor Networks

We present a novel application of Tensor Network methods in cancer treatment as a potential tool to solve the dose optimization problem in radiotherapy. In particular, the intensity-modulated radiation therapy technique-that allows treating irregular and inhomogeneous tumors while reducing the radiation toxicity on healthy organs-is based on the optimization problem of the beamlets intensities that shall result in a maximal delivery of the therapy dose to cancer while avoiding the organs at risk of being damaged by the radiation. The resulting optimization problem is expressed as a cost function to be optimized. Here, we map the cost function into an Ising-like Hamiltonian, describing a system of long-range interacting qubits. Finally, we solve the dose optimization problem by finding the ground-state of the Hamiltonian using a Tree Tensor Network algorithm. In particular, we present an anatomical scenario exemplifying a prostate cancer treatment. A similar approach can be applied to future hybrid classical-quantum algorithms, paving the way for the use of quantum technologies in future medical treatments.

Intracranial response after extracranial radiation in a patient with rapidly progressing metastatic melanoma

Growing literature supports the synergistic effect of radiation as a primer for renewed enhanced systemic immunological responses in patients receiving immunotherapy for metastatic melanoma. Radiographic regression of extracranial tumours after treatment of intracranial metastatic lesions has been reported and these observations point to an abscopal effect that traverses the blood-brain barrier. We describe a patient with rapidly progressing metastatic melanoma despite combined immune checkpoint blockade, who achieved a complete metabolic response of both his extracranial and intracranial disease after the commencement of palliative radiation to his axilla. This is the first published case, to our knowledge, of a sustained, complete intracranial abscopal response from extracranial radiation. We discuss potential mechanistic relations between radiation, the blood-brain barrier and the abscopal effect.

Immunotherapy in association with stereotactic radiotherapy for Non-Small Cell Lung Cancer brain metastases: results from a multicentric retrospective study on behalf of AIRO

BACKGROUND

To define efficacy and toxicity of Immunotherapy (IT) with stereotactic radiotherapy (SRT) including radiosurgery (RS) or hypofractionated SRT (HFSRT) for brain metastases (BM) from Non-Small Cell Lung Cancer (NSCLC) in a multicentric retrospective study from AIRO (Italian Association of Radiotherapy and Clinical Oncology).

METHODS

NSCLC patients with BM receiving SRT+IT and treated in 19 Italian centers were analysed and compared with a control group of patients treated with exclusive SRT.

RESULTS

One hundred patients treated with SRT+IT and 50 patients treated with SRT-alone were included. Patients receiving SRT+IT had a longer intracranial Local Progression Free Survival (iLPFS) (propensity score-adjusted p=0.007). Among patients who, at the diagnosis of BM, received IT and had also extracranial progression (n=24), IT administration after SRT was shown to be related to a better overall survival (OS) (p=0.037). At multivariate analysis, non-adenocarcinoma histology, KPS =70 and use of HFSRT were associated with a significantly worse survival (p=0.019, p=0.017 and p=0.007 respectively). Time interval between SRT and IT ≤7 days (n=90) was shown to be related to a longer OS if compared to SRT-IT interval >7 days (n=10) (propensity score-adjusted p=0.008). The combined treatment was well tolerated. No significant difference in terms of radionecrosis between SRT+IT patients and SRT-alone patients was observed. Time interval between SRT and IT had no impact on toxicity rate.

CONCLUSIONS

Combined SRT+IT was a safe approach, associated with a better iLPFS if compared to exclusive SRT.

Immune Checkpoint Inhibition as a Strategy in the Neoadjuvant Treatment of Locally Advanced Rectal Cancer

The treatment of locally advanced rectal cancer (LARC) has seen major advances over the past 3 decades, with multimodality treatment now standard of care. Combining surgical resection with radiotherapy and/or chemotherapy can reduce local recurrence from around 20% to approximately 5%. Despite improvements in local control, distant recurrence and subsequent survival rates have not changed. Immune checkpoint inhibitors have improved patient outcomes in several solid tumor types in the neoadjuvant, adjuvant, and advanced disease setting; however, in colorectal cancer, most clinical trials have been performed in the metastatic setting and the benefits confined to microsatellite instability-high tumors. In this article, we review the current preclinical and clinical evidence for using immune checkpoint inhibition in the treatment of LARC and discuss the rationale for specifically exploring the use of this therapy in the neoadjuvant setting. We summarize and discuss relevant clinical trials that are currently in setup and recruiting to test this treatment strategy and reflect on unanswered questions that still need to be addressed within future research efforts.

A narrative review of combining radiation and immunotherapy in gastroesophageal cancers

Despite advances in chemotherapy, radiation, and surgery, prognosis in gastroesophageal cancers (GEC) remains poor. Recent studies have demonstrated that immune checkpoint inhibitors specific to the PD-1/PD-L1 axis can improve survival with dramatic durability for a subset of patients with GEC. Radiation therapy (RT) has been shown to enhance priming and anti-tumor immunogenicity. The combination of these two treatments has shown promising results acting synergistically in pre-clinical and clinical models. Much of this synergy appears linked to in-field radiation responses, but also the abscopal response where out-of-field tumors demonstrate regression. In this review, we summarize the current role of immunotherapy and radiation in GEC. We also highlight progress from preclinical studies and translational biomarker analyses that provide rationale for ongoing efforts combining immune checkpoint inhibition and radiotherapy specifically in GECs. Questions that remain unanswered in the clinic are the optimal radiation dosing, timing, and fractionation strategies to augment abscopal immune responses. Increasing recognition of the heterogeneity of immunosuppressive mechanisms that can arise in response to radiation indicates the need for novel immune checkpoint inhibitors that target beyond the PD-1/PD-L1 axis. Smartly designed prospective trials incorporating these two approaches with ongoing translational analyses will be critical in increasing the success of combinatorial radiation and immunotherapy strategies in this disease.

Research and application of hydrostatic high pressure in tumor vaccines (Review)

It is well known that hydrostatic pressure (HP) is a physical parameter that is now regarded as an important variable for life. High hydrostatic pressure (HHP) technology has influenced biological systems for more than 100 years. Food and bioscience researchers have shown great interest in HHP technology over the past few decades. The development of knowledge related to this area can better facilitate the application of HHP in the life sciences. Furthermore, new applications for HHP may come from these current studies, particularly in tumor vaccines. Currently, cancer recurrence and metastasis continue to pose a serious threat to human health. The limited efficacy of conventional treatments has led to the need for breakthroughs in immunotherapy and other related areas. Research into tumor vaccines is providing new insights for cancer treatment. The purpose of this review is to present the main findings reported thus far in the relevant scientific literature, focusing on knowledge related to HHP technology and tumor vaccines, and to demonstrate the potential of applying HHP technology to tumor vaccine development.

The oncogenic and clinical implications of lactate induced immunosuppression in the tumour microenvironment

The tumour microenvironment is of critical importance in cancer development and progression and includes the surrounding stromal and immune cells, extracellular matrix, and the milieu of metabolites and signalling molecules in the intercellular space. To support sustained mitotic activity cancer cells must reconfigure their metabolic phenotype. Lactate is the major by-product of such metabolic alterations and consequently, accumulates in the tumour. Lactate actively contributes to immune evasion, a hallmark of cancer, by directly inhibiting immune cell cytotoxicity and proliferation. Furthermore, lactate can recruit and induce immunosuppressive cell types, such as regulatory T cells, tumour-associated macrophages, and myeloid-derived suppressor cells which further suppress anti-tumour immune responses. Given its roles in oncogenesis, measuring intratumoural and systemic lactate levels has shown promise as a both predictive and prognostic biomarker in several cancer types. The efficacies of many anti-cancer therapies are limited by an immunosuppressive TME in which lactate is a major contributor, therefore, targeting lactate metabolism is a priority. Developing inhibitors of key proteins in lactate metabolism such as GLUT1, hexokinase, LDH, MCT and HIF have shown promise in preclinical studies, however there is a corresponding lack of success in human trials so far. This may be explained by a weakness of preclinical models that fail to reproduce the complexities of metabolic interactions in natura. The future of these therapies may be as an adjunct to more conventional treatments.

Immunosuppression in Gliomas via PD-1/PD-L1 Axis and Adenosine Pathway

Glioblastoma is the most malignant and lethal subtype of glioma. Despite progress in therapeutic approaches, issues with the tumor immune landscape persist. Multiple immunosuppression pathways coexist in the tumor microenvironment, which can determine tumor progression and therapy outcomes. Research in immune checkpoints, such as the PD-1/PD-L1 axis, has renewed the interest in immune-based cancer therapies due to their ability to prevent immunosuppression against tumors. However, PD-1/PD-L1 blockage is not completely effective, as some patients remain unresponsive to such treatment. The production of adenosine is a major obstacle for the efficacy of immune therapies and is a key source of innate or adaptive resistance. In general, adenosine promotes the pro-tumor immune response, dictates the profile of suppressive immune cells, modulates the release of anti-inflammatory cytokines, and induces the expression of alternative immune checkpoint molecules, such as PD-1, thus maintaining a loop of immunosuppression. In this context, this review aims to depict the complexity of the immunosuppression in glioma microenvironment. We primarily consider the PD-1/PD-L1 axis and adenosine pathway, which may be critical points of resistance and potential targets for tumor treatment strategies.

Therapeutic enhancement of radiation and immunomodulation by gold nanoparticles in triple negative breast cancer

Gold nanoparticles (AuNPs) have been shown to enhance cancer radiotherapy (RT) gain by localizing the absorption of radiation energy in the tumor while sparing surrounding normal tissue from radiation toxicity. Previously, we showed that AuNPs enhanced RT induced DNA damage and cytotoxicity in MCF7 breast cancer cells. Interestingly, we found that cancer cells exhibited a size-dependent AuNPs intracellular localization (4 nm preferentially in the cytoplasm and 14 nm in the nucleus). We extended those studies to an in vivo model and examined the AuNPs effects on RT cytotoxicity, survival and immunomodulation of tumor microenvironment (TME) in human triple negative breast cancer (TNBC) xenograft mouse model. We also explored the significance of nanoparticle size in these AuNPs’ effects. Mice treated with RT and RT plus 4 nm or 14 nm AuNPs showed a significant tumor growth delay, compared to untreated animals, while dual RT plus AuNPs treatment exhibited additive effect compared to either RT or AuNPs treatment alone. Survival log-rank test showed significant RT enhancement with 14 nm AuNP alone; however, 4 nm AuNPs did not exhibit RT enhancement. Both sizes of AuNPs enhanced RT induced immunogenic cell death (ICD) that was coupled with significant macrophage infiltration in mice pretreated with 14 nm AuNPs. These results showing significant AuNP size-dependent RT enhancement, as evident by both tumor growth delay and overall survival, reveal additional underlying immunological mechanisms and provide a platform for studying RT multimodal approaches for TNBC that may be combined with immunotherapies, enhancing their effect.

A Prospective Trial Evaluating the Safety and Systemic Response From the Concurrent Use of Radiation Therapy with Checkpoint Inhibitor Immunotherapy in Metastatic Non-Small Cell Lung Cancer

INTRODUCTION/BACKGROUND

This study assessed the safety and systemic (abscopal) response from the addition of local stereotactic body radiation therapy (SBRT) to checkpoint inhibitor (CPI) immunotherapy in patients with metastatic non-small cell lung cancer.

PATIENTS/METHODS

Thirty-five patients with at least 2 sites of measurable disease on PET/CT received standard-of-care CPI immunotherapy alone (n = 19), or in combination with 4 cycles doublet carboplatin/pemetrexed chemotherapy (n = 16), and 3 to 5 fractions SBRT to a single extracranial target lesion between cycles 1 to 2 of the systemic therapy. Adverse events were assessed using CTCAE version 5.0. Best systemic objective response rate (ORR) was assessed using iRECIST criteria, excluding any irradiated lesion(s). Additional SBRT to a different target lesion was offered to patients who continued on immunotherapy with unconfirmed progressive disease or mixed response.

RESULTS

Fifteen patients (44%) experienced 22 grade 1 to 2 toxicities potentially attributable to radiation, most commonly pneumonitis (n = 9) and fatigue (n = 6), and no grade 3 to 5 radiation-induced toxicities. Patients undergoing combined CPI-chemotherapy received a lower median biologically effective dose of SBRT than those undergoing CPI monotherapy (43.2 vs. 60Gy), but had a higher rate of radiation-induced toxicity (56% vs. 32%, P < .01). The best systemic ORR was 53%, with 20.5% stable disease and 26.5% progressive disease. Fifteen patients underwent a subsequent course of SBRT based on their response, among which 3 (20%) had progression-free intervals of 12, 16, and 10 months thereafter.

CONCLUSIONS

Addition of SBRT to CPI immunotherapy (with/without chemotherapy) is safe. The favorable systemic response observed warrants further assessment with a randomized trial.

Optimizing the Combination of Immunotherapy and Trans-Arterial Locoregional Therapy for Stages B and C Hepatocellular Cancer

Hepatocellular carcinoma (HCC), the most common primary hepatic malignancy worldwide, is the second leading cause of cancer-related death. Underlying liver dysfunction and advanced stage of disease require treatments to be optimally timed and implemented to minimize hepatic parenchymal damage while maximizing disease response and quality of life. Locoregional therapies (LRTs) such as trans-arterial chemo- and radio-embolization remain effective for intermediate liver-only and advanced HCC disease (i.e., Barcelona-Clinic liver cancer stages B and C) not amendable to primary resection or ablation. Additionally, these minimally invasive interventions have been shown to augment the immune system. This and the recent success of immune-oncologic treatments for HCC have generated interest in applying these therapies in combination with such locoregional interventions to improve patient outcomes and response rates. This report reviews the use of trans-arterial LRTs with immunotherapy for stages B and C HCC, potential biomarkers, and imaging methods for assessing the response and safety of such combinations.

Therapeutic vaccines for aggressive B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive B-cell lymphoma and highly heterogeneous disease. With the standard immunochemotherapy, anti-CD20 antibody rituximab (R-) plus CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy, 30-40% of DLBCLs are refractory to initial immunochemotherapy or experience relapse post-therapy with poor clinical outcomes despite salvage therapies. Mechanisms underlying chemoresistance and relapse are heterogeneous across DLBCL and within individual patients, representing hurdles for targeted therapies targeting a specific oncogenic signaling pathway. In recent years, paradigm-shifting immunotherapies have shown impressive efficacy in various cancer types regardless of underlying oncogenic mechanisms. Vaccines are being developed for DLBCL to build protective immunity against relapse after first complete remission and to promote antitumor immune responses synergizing with immune checkpoint inhibitors to treat refractory/relapsed patients. This article provides a brief review of current progress in vaccine development in DLBCL and discussion on immunologic mechanisms underlying the therapeutic effectiveness and resistance.

Are antiangiogenics a good 'partner' for immunotherapy in ovarian cancer?

Ovarian cancer (OC) is associated with poor survival because there are a limited number of effective therapies. Two processes key to OC progression, angiogenesis and immune evasion, act synergistically to promote tumor progression. Tumor-associated angiogenesis promotes immune evasion, and tumor-related immune responses in the peritoneal cavity and tumor microenvironment (TME) affect neovascular formation. Therefore, suppressing the angiogenic pathways could facilitate the arrival of immune effector cells and reduce the presence of myeloid cells involved in immune suppression. To date, clinical studies have shown significant benefits with antiangiogenic therapy as first-line therapy in OC, as well as in recurrent disease, and the vascular endothelial growth factor (VEGF) inhibitor bevacizumab is now an established therapy. Clinical data with immunomodulators in OC are more limited, but suggest that they could benefit some patients with recurrent disease. The preliminary results of two phase III trials have shown that the addition of immunomodulators to chemotherapy does not improve progression-free survival. For this reason, it could be interesting to look for synergistic effects between immunomodulators and other active drugs in OC. Since bevacizumab is approved for use in OC, and is tolerable when used in combination with immunotherapy in other indications, a number of clinical studies are underway to investigate the use of bevacizumab in combination with immunotherapeutic agents in OC. This strategy seeks to normalize the TME via the anti-VEGF actions of bevacizumab, while simultaneously stimulating the immune response via the immunotherapy. Results of these studies are awaited with interest.

Converging focal radiation and immunotherapy in a preclinical model of triple negative breast cancer: contribution of VISTA blockade

Antibodies targeting the co-inhibitory receptor programmed cell death 1 (PDCD1, best known as PD-1) or its main ligand CD274 (best known as PD-L1) have shown some activity in patients with metastatic triple-negative breast cancer (TNBC), especially in a recent Phase III clinical trial combining PD-L1 blockade with taxane-based chemotherapy. Despite these encouraging findings, however, most patients with TNBC fail to derive significant benefits from PD-L1 blockade, calling for the identification of novel therapeutic approaches. Here, we used the 4T1 murine mammary cancer model of metastatic and immune-resistant TNBC to test whether focal radiation therapy (RT), a powerful inducer of immunogenic cell death, in combination with various immunotherapeutic strategies can overcome resistance to immune checkpoint blockade. Our results suggest that focal RT enhances the therapeutic effects of PD-1 blockade against primary 4T1 tumors and their metastases. Similarly, the efficacy of an antibody specific for V-set immunoregulatory receptor (VSIR, another co-inhibitory receptor best known as VISTA) was enhanced by focal RT. Administration of cyclophosphamide plus RT and dual PD-1/VISTA blockade had superior therapeutic effects, which were associated with activation of tumor-infiltrating CD8⁺ T cells and depletion of intratumoral granulocytic myeloid-derived suppressor cells (MDSCs). Overall, these results demonstrate that RT can sensitize immunorefractory tumors to VISTA or PD-1 blockade, that this effect is enhanced by the addition of cyclophosphamide and suggest that a multipronged immunotherapeutic approach may also be required to increase the incidence of durable responses in patients with TNBC.

Patterns of disease progression to checkpoint inhibitor immunotherapy in patients with stage IV non-small cell lung cancer

INTRODUCTION

The purpose of this study was to assess patterns of disease progression for patients with metastatic non-small cell lung cancer (NSCLC) on checkpoint inhibitor immunotherapy.

METHODS

This single centre, retrospective study included all patients diagnosed with Stage IV NSCLC from 2015 to 2019 who received at least 2 cycles of immunotherapy, with or without concurrent chemotherapy. Immune RECIST criteria were used to assess patterns of disease progression, and progression-free survival (PFS), excluding irradiated tumours. The chi-square and log-rank tests assessed for associations between baseline clinical characteristics and progressive disease in initial sites only (vs. new or combined sites), and PFS, respectively.

RESULTS

Among 143 eligible patients with a median follow-up of 11 months, 97 (68%) developed disease progression. Of these, 67 patients (69.1%) progressed only at initial disease site(s), 10 patients (10.3%) progressed only at new disease site(s), and 20 patients (20.6%) progressed in both initial and new sites. Rates of disease progression based on tumour location were higher for liver (64%) and lung metastases (61%) than for other metastatic sites (33-36%) or the primary tumour (24%). Only higher PD-L1 expression (P = 0.002) and absence of lung metastasis (P = 0.048) at baseline were associated with improved PFS. No baseline characteristics significantly impacted the probability of initial disease site-only progression, though a trend was observed for untreated primary tumour (72% vs. 56%, P = 0.169).

CONCLUSIONS

The dominant pattern of disease progression is in the initial sites of disease alone, suggesting a potential role for local radiation therapy as a complementary treatment modality to immunotherapy.

Emerging technologies for local cancer treatment

The fundamental limitations of systemic therapeutic administration have prompted the development of local drug delivery platforms as a solution to increase effectiveness and reduce side effects. By confining therapeutics to the site of disease, local delivery technologies can enhance therapeutic index. This review highlights recent advances and opportunities in local drug delivery strategies for cancer treatment in addition to challenges that need to be addressed to facilitate clinical translation. The benefits of local cancer treatment combined with technological advancements and increased understanding of the tumor microenvironment, present a prime breakthrough opportunity for safer and more effective therapies.

Modulation of Immuno-biome during Radio-sensitization of Tumors by Glycolytic Inhibitors

The Tumor Microenvironment (TME) comprising stromal cells, fibroblasts and various components of the immune system forms a pro-tumorigenic cocoon around the tumor cells with the reprogramming of the metabolism in the form of Warburg phenotype (enhanced aerobic glycolysis) in tumor as well as non-tumor cells. This reprogramming plays a significant role in suppressing the immune response leading to the survival and proliferation of tumor cells and resistance to therapies. Therefore, there is a considerable interest in developing strategies involving metabolic modifiers to improve the therapeutic efficacy that restores immune competence, besides enhancing the direct effects on tumor cells. Inhibitors of glycolysis like 2-deoxy-D-glucose (2-DG; a hexokinase inhibitor), dichloroacetate and small molecule inhibitors of lactate transport (MCT-1) are some of the metabolic modifiers investigated for their therapeutic as well as adjuvant potential. Among these, 2-DG has been widely investigated and established as an ideal adjuvant in the radio- and chemotherapy of tumors. Modulation of the immuno-biome in the form of cytokine shifts, differential transcriptional regulation, abrogation of immunosuppressive network and reduced accumulation of lactate are some of the contributing factors for immune stimulation linked to the radio- and chemosensitization by glycolytic inhibitors.

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.

Dendritic Cell Maturation Defines Immunological Responsiveness of Tumors to Radiation Therapy

Radiation therapy is capable of directing adaptive immune responses against tumors by stimulating the release of endogenous adjuvants and tumor-associated Ags. Within the tumor, conventional type 1 dendritic cells (cDC1s) are uniquely positioned to respond to these signals, uptake exogenous tumor Ags, and migrate to the tumor draining lymph node to initiate cross-priming of tumor-reactive cytotoxic CD8⁺ T cells. In this study, we report that radiation therapy promotes the activation of intratumoral cDC1s in radioimmunogenic murine tumors, and this process fails to occur in poorly radioimmunogenic murine tumors. In poorly radioimmunogenic tumors, the adjuvant polyinosinic-polycytidylic acid overcomes this failure following radiation and successfully drives intratumoral cDC1 maturation, ultimately resulting in durable tumor cures. Depletion studies revealed that both cDC1 and CD8⁺ T cells are required for tumor regression following combination therapy. We further demonstrate that treatment with radiation and polyinosinic-polycytidylic acid significantly expands the proportion of proliferating CD8⁺ T cells in the tumor with enhanced cytolytic potential and requires T cell migration from lymph nodes for therapeutic efficacy. Thus, we conclude that lack of endogenous adjuvant release or active suppression following radiation therapy may limit its efficacy in poorly radioimmunogenic tumors, and coadministration of exogenous adjuvants that promote cDC1 maturation and migration can overcome this limitation to improve tumor control following radiation therapy.

Rationale of combination of anti-PD-1/PD-L1 antibody therapy and radiotherapy for cancer treatment

Significant technological advances in radiotherapy have been made in the past few decades. High-precision radiotherapy has recently become popular and is contributing to improvements in the local control of the irradiated target lesions and the reduction of adverse effects. Accordingly, for long-term survival, the importance of systemic cancer control, including at non-irradiated sites, is growing. Toward this challenge, the treatment methods in which anti-PD-1/PD-L1 antibodies that exert systemic effects by restoring anti-tumour immunity are combined with radiotherapy has attracted attention in recent years. Previous studies have reported the activation of anti-tumour immunity by radiotherapy, which simultaneously elevates PD-L1 expression, suggesting a potential for combination therapy. Radiotherapy induces so-called ‘immunogenic cell death’, which involves cell surface translocation of calreticulin and extracellular release of high-mobility group protein box 1 (HMGB-1) and adenosine-5′-triphosphate (ATP). Furthermore, radiotherapy causes immune activation via MHC class I upregulation and cGAS–STING pathway. In contrast, induction of immunosuppressive lymphocytes and the release of immunosuppressive cytokines and chemokines by radiotherapy contribute to immunosuppressive reactions. In this article, we review immune responses induced by radiotherapy as well as previous reports to support the rationale of combination of radiotherapy and anti-PD-1/PD-L1 antibodies. A number of preclinical and clinical studies have shown the efficacy of radiotherapy combined with immune checkpoint inhibition, hence combination therapy is considered to be an important future strategy for cancer treatment.

Molecular Mechanisms of Radiation-Induced Cancer Cell Death: A Primer

Radiation therapy (RT) is responsible for at least 40% of cancer cures, however treatment resistance remains a clinical problem. There have been recent advances in understanding the molecular mechanisms of radiation-induced cell death. The type of cell death after radiation depends on a number of factors including cell type, radiation dose and quality, oxygen tension, TP53 status, DNA repair capacity, cell cycle phase at time of radiation exposure, and the microenvironment. Mitotic catastrophe (a pathway preceding cell death that happens in mitosis or as a consequence of aberrant mitotic progression) is the primary context of radiation-induced cell death in solid cancers, although in a small subset of cancers such as haematopoietic malignancies, radiation results in immediate interphase apoptosis, occurring within hours after exposure. There is intense therapeutic interest in using stereotactic ablative body radiotherapy (SABR), a precise, high-dose form of RT given in a small number of fractions, to prime the immune system for cancer cell killing, but the optimal radiation dose and fractionation remain unclear. Additionally, promising novel radiosensitisers targeting the cell cycle and DNA repair pathways are being trialled. In the context of the increasing use of SABR and such novel agents in the clinic, we provide an updated primer on the major types of radiation-induced cell death, focussing on their molecular mechanisms, factors affecting their initiation, and their implications on immunogenicity.

Assessing the Magnitude of Immunogenic Cell Death Following Chemotherapy and Irradiation Reveals a New Strategy to Treat Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) continues to have a dismal prognosis, in part, due to ineffective treatment strategies. The efficacy of some chemotherapies and especially radiotherapy is mediated partially by the immune system. Therefore, we hypothesized that profiling the immune response following chemotherapy and/or irradiation can be used as a readout for treatment efficacy but also to help identify optimal therapeutic schedules for PDAC. Using murine models of PDAC, we demonstrated that concurrent administration of stereotactic body radiotherapy (SBRT) and a modified dose of FOLFIRINOX (mFX) resulted in superior tumor control when compared with single or sequential treatment groups. Importantly, this combined treatment schedule enhanced the magnitude of immunogenic cell death, which in turn amplified tumor antigen presentation by dendritic cells and intratumoral CD8+ T-cell infiltration. Concurrent therapy also resulted in systemic immunity contributing to the control of established metastases. These findings provide a rationale for pursuing concurrent treatment schedules of SBRT with mFX in PDAC.

Construction of Nucleus-Targeting Iridium Nanocrystals for Photonic Hyperthermia-Synergized Cancer Radiotherapy

Prominent tumor-cell nucleus targeting of radiosensitizer substantially affects the therapeutic consequence of advanced tumor radiotherapy via lethal nucleus DNA damage. Herein, ultrasmall iridium nanocrystals (Ir NCs, <5 nm) are constructed for efficient tumor-specific photonic hyperthermia-synergized radiotherapy. To endow the NCs with qualified cell nucleus-targeting performance, polyethylene glycol (PEG)-modified Ir NCs are decorated with αv β3 integrin-targeting cyclic arginine-glycine-aspartic (c(RGDyC)), designated as RGD, peptides and human immunodeficiency virus-1 transactivator of transcription protein(TAT), respectively, facilitating the tumor-cell-membrane (with overexpressed αv β3 integrin) and cell-nucleus targeting. The formulated Ir-RGD-TAT (Ir-R/T) NCs are demonstrated to accumulate inside the nucleus of tumor cells and generate effective DNA lesions upon X-ray irradiation. Further in vivo evaluations verify the satisfactory carcinoma destruction performance against 4T1 tumor xenografts. Importantly, the intriguing photonic NIR adsorption of Ir-R/T NCs has enabled the hyperthermia therapeutics accompanied with photoacoustic imaging modalities, achieving clinically promising biocompatible multifunctional radiosensitized nanoplatforms for effective tumor therapeutics.

Adenosine Blockage in Tumor Microenvironment and Improvement of Cancer Immunotherapy

Immunotherapy has been introduced into cancer treatment methods, but different problems have restricted the efficacy of these protocols in clinical trials such as the presence of various immunomodulatory factors in the tumor microenvironment. Adenosine is an immunosuppressive metabolite produced by the tumor to promote growth, invasion, metastasis, and immune evasion. Many studies about adenosine and its metabolism in cancer have heightened interest in pursuing this treatment approach. It seems that targeting the adenosine pathway in combination with immunotherapy may lead to efficient antitumor response. In this review, we provide information on the roles of both adenosine and CD73 in the immune system and tumor development. We also describe recent studies about combination therapy with both purinergic inhibitors and other immunotherapeutic methods.

Imaging of Activated T Cells as an Early Predictor of Immune Response to Anti-PD-1 Therapy

Compelling evidence points to immune cell infiltration as a critical component of successful immunotherapy. However, there are currently no clinically available, noninvasive methods capable of evaluating immune contexture prior to or during immunotherapy. In this study, we evaluate a T-cell-specific PET agent, [18F]F-AraG, as an imaging biomarker predictive of response to checkpoint inhibitor therapy. We determined the specificity of the tracer for activated T cells in vitro and in a virally induced model of rhabdomyosarcoma. Of all immune cells tested, activated human CD8⁺ effector cells showed the highest accumulation of [18F]F-AraG. Isolation of lymphocytes from the rhabdomyosarcoma tumors showed that more than 80% of the intratumoral signal came from accumulation of [18F]F-AraG in immune cells, primarily CD8⁺ and CD4⁺. Longitudinal monitoring of MC38 tumor-bearing mice undergoing anti-PD-1 treatment revealed differences in signal between PD-1 and isotype antibody-treated mice early into treatment. The differences in [18F]F-AraG signal were also apparent between responders and nonresponders to anti-PD-1 therapy. Importantly, we found that the signal in the tumor-draining lymph nodes provides key information about response to anti-PD-1 therapy. Overall, [18F]F-AraG has potential to serve as a much needed immunomonitoring clinical tool for timely evaluation of immunotherapy. SIGNIFICANCE: These findings reveal differences in T-cell activation between responders and nonresponders early into anti-PD-1 treatment, which may impact many facets of immuno-oncology, including patient selection, management, and development of novel combinatorial approaches.

Nanomedicine and macroscale materials in immuno-oncology

Immunotherapy is revolutionizing the treatment of cancer. It can achieve unprecedented responses in advanced-stage patients, including complete cures and long-term survival. However, immunotherapy also has limitations, such as its relatively low response rates and the development of severe side effects. These drawbacks are gradually being overcome by improving our understanding of the immune system, as well as by establishing combination regimens in which immunotherapy is combined with other treatment modalities. In addition to this, in recent years, progress made in chemistry, nanotechnology and materials science has started to impact immuno-oncology, resulting in more effective and less toxic immunotherapy interventions. In this context, multiple different nanomedicine formulations and macroscale materials have been shown to be able to boost anti-cancer immunity and the efficacy of immunomodulatory drugs. We here review nanotechnological and materials chemistry efforts related to endogenous and exogenous vaccination, to the engineering of antigen-presenting cells and T cells, and to the modulation of the tumor microenvironment. We also discuss limitations, current trends and future directions. Together, the insights provided and the evidence obtained indicate that there is a bright future ahead for engineering nanomedicines and macroscale materials for immuno-oncology applications.

Local biomaterials-assisted cancer immunotherapy to trigger systemic antitumor responses

Cancer immunotherapy by educating or stimulating patients’ own immune systems to attack cancer cells has demonstrated promising therapeutic responses in the clinic.

Prostate cancer: updates on current strategies for screening, diagnosis and clinical implications of treatment modalities

Prostate cancer is the most common cancer in men by way of diagnosis and a leading cause of cancer-related deaths. Early detection and intervention remains key to its optimum clinical management. This review provides the most updated information on the recent methods of prostate cancer screening, imaging and treatment modalities. Wherever possible, clinical trial data has been supplemented to provide a comprehensive overview of current prostate cancer research and development. Considering the recent success of immunotherapy in prostate cancer, we discuss cell, DNA and viruses based, as well as combinatorial immunotherapeutic strategies in detail. Furthermore, the potential of nanotechnology is increasingly being realized, especially in prostate cancer research, and we provide an overview of nanotechnology-based strategies, with special emphasis on nanotheranostics and multifunctional nanoconstructs. Understanding these recent developments is critical to the design of future therapeutic strategies to counter prostate cancer.

Reduction of circulating lymphocyte count is a predictor of good tumor response after neoadjuvant treatment for rectal cancer

Systemic inflammatory indices are correlated with poor prognosis in cancer patients. The presence of lymphocytes in and around the tumor tissue is a predictor in rectal cancer. We aimed to explore the mechanism underlying the changes in circulating lymphocyte during neoadjuvant therapy and the way in which the count correlates with tumor response.Around 307 patients from FOWARC trial and 64 patients from FORTUNE trial were included in the training and validation group. Circulating lymphocyte count was recorded before neoadjuvant therapy and before rectal surgery. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off value of the reduction of lymphocytes. A logistic regression model was obtained in multivariate analysis.The blood absolute number of lymphocyte before and after therapy had no correlation with tumor response. However, total lymphocyte count (TLC) reduction was significantly higher in good response group (39.81% vs 33.31% P = .032) in the FOWARC cohort. The optimal cut-off value for TLC was 24.96%. Age, tumor length, and TLC reduction (P = .005, OR = 2.009, 95%CI 1.240-3.254) were significant factors for tumor regression in multivariate analysis. In the FORTUNE cohort, TLC reduction was the only significant factor for tumor regression in both univariate (P = .032, OR = 3.434, 95%CI 1.111-10.614) and multivariate analysis (P = .046, OR = 3.361, 95%CI 1.024-11.035).Circulating lymphocyte count decreases during neoadjuvant therapy for locally advanced rectal cancer, and it is associated with better tumor regression. It may be involved in the immune response provoked by radiotherapy and chemotherapy.

Nanoscale metal-organic frameworks enhance radiotherapy to potentiate checkpoint blockade immunotherapy

Checkpoint blockade immunotherapy enhances systemic antitumor immune response by targeting T cell inhibitory pathways; however, inadequate T cell infiltration has limited its anticancer efficacy. Radiotherapy (RT) has local immunomodulatory effects that can alter the microenvironment of irradiated tumors to synergize with immune checkpoint blockade. However, even with high doses of radiation, RT has rarely elicited systemic immune responses. Herein, we report the design of two porous Hf-based nanoscale metal-organic frameworks (nMOFs) as highly effective radioenhancers that significantly outperform HfO2, a clinically investigated radioenhancer in vitro and in vivo. Importantly, the combination of nMOF-mediated low-dose RT with an anti-programmed death-ligand 1 antibody effectively extends the local therapeutic effects of RT to distant tumors via abscopal effects. Our work establishes the feasibility of combining nMOF-mediated RT with immune checkpoint blockade to elicit systemic antitumor immunity in non-T cell-inflamed tumor phenotypes without normal tissue toxicity, promising to broaden the application of checkpoint blockade immunotherapy.

Radiation therapy and PD-1/PD-L1 blockade: the clinical development of an evolving anticancer combination

Several inhibitors of programmed cell death-1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved as a form of immunotherapy for multiple cancers. Ionizing radiation therapy (RT) has been shown to enhance the priming and effector phases of the antitumor T-cell response rendering it an attractive therapy to combine with PD-1/PD-L1 inhibitors. Preclinical data support the rational combination of the 2 modalities and has paved way for the clinical development of the combination across a spectrum of cancers. In this review, we highlight the preclinical and clinical development of combined RT and PD-1/PD-L1 blockade to date. In addition to a comprehensive evaluation of available safety and efficacy data, we discuss important points of consideration in clinical trial design for this promising combination.

Abscopal, immunological effects of radiotherapy: Narrowing the gap between clinical and preclinical experiences

Radiotherapy-despite being a local therapy that meanwhile is characterized by an impressively high degree of spatial accuracy-can stimulate systemic phenomena which occasionally lead to regression and rejection of non-irradiated, distant tumor lesions. These abscopal effects of local irradiation have been observed in sporadic clinical case reports since the beginning of the 20th century, and extensive preclinical work has contributed to identify systemic anti-tumor immune responses as the underlying driving forces. Although abscopal tumor regression still remains a rare event in the radiotherapeutic routine, increasing numbers of cases are being reported, particularly since the clinical implementation of immune checkpoint inhibiting agents. Accordingly, interests to systematically exploit the therapeutic potential of radiotherapy-stimulated systemic responses are constantly growing. The present review briefly delineates the history of radiotherapy-induced abscopal effects and the activation of systemic anti-tumor immune responses by local irradiation. We discuss preclinical and clinical reports with specific focus on the corresponding controversies, and we propose issues that should be addressed in the future in order to narrow the gap between preclinical knowledge and clinical experiences.

The importance of the vascular endothelial barrier in the immune-inflammatory response induced by radiotherapy

Altered by ionising radiation, the vascular network is considered as a prime target to limit normal tissue damage and improve tumour control in radiotherapy (RT). Irradiation damages and/or activates endothelial cells, which then participate in the recruitment of circulating cells, especially by overexpressing cell adhesion molecules, but also by other as yet unknown mechanisms. Radiation-induced lesions are associated with infiltration of immune-inflammatory cells from the blood and/or the lymph circulation. Damaged cells from the tissues and immune-inflammatory resident cells release factors that attract cells from the circulation, leading to the restoration of tissue balance by fighting against infection, elimination of damaged cells and healing of the injured area. In normal tissues that surround the tumours, the development of an immune-inflammatory reaction in response to radiation-induced tissue injury can turn out to be chronic and deleterious for the organ concerned, potentially leading to fibrosis and/or necrosis of the irradiated area. Similarly, tumours can elicit an immune-inflammation reaction, which can be initialised and amplified by cancer therapy such as radiotherapy, although immune checkpoints often allow many cancers to be protected by inhibiting the T-cell signal. Herein, we have explored the involvement of vascular endothelium in the fate of healthy tissues and tumours undergoing radiotherapy. This review also covers current investigations that take advantage of the radiation-induced response of the vasculature to spare healthy tissue and/or target tumours better.