Low-dose ionizing γ-radiation elicits the extrusion of neutrophil extracellular traps.

PURPOSE: Cancer patients frequently undergo radiotherapy in their clinical management with unintended irradiation of blood vessels and copiously irrigated organs in which polymorphonuclear leukocytes circulate. Following the observation that such low doses of ionizing radiation are able to induce neutrophils to extrude neutrophil extracellular traps (NETs), we have investigated the mechanisms, consequences and the occurrence of such phenomena in patients undergoing radiotherapy. EXPERIMENTAL DESIGN: NETosis was analyzed in cultures of neutrophils isolated from healthy donors, cancer patients and cancer-bearing mice under confocal microscopy. Cocultures of radiation-induced NETs, immune effector lymphocytes and tumor cells were used to study the effects of irradiation-induced NETs on immune cytotoxicity. Radiation-induced NETs were intravenously injected to mice assessing their effects on metastasis. Circulating NETs in irradiated cancer patients were measured by ELISA methods detecting MPO-DNA complexes and citrullinated H3. RESULTS: Very low γ-radiation doses (0.5-1 Gy) given to neutrophils elicit NET formation in a manner dependent on oxidative stress, NADPH oxidase activity and autocrine interleukin-8. Radiation-induced NETs interfere with NK- and T-cell cytotoxicity. As a consequence, pre-injection of irradiation-induced NETs increases the number of successful metastases in mouse tumor models. Increases in circulating NETs were readily detected in two prospective series of patients following the first fraction of their radiotherapy courses. CONCLUSIONS: NETosis is induced by low-dose ionizing irradiation in a neutrophil-intrinsic fashion and radiation-induced NETs are able to interfere with immune-mediated cytotoxicity. Radiation-induced NETs foster metastasis in mouse models and can be detected in the circulation of patients undergoing conventional radiotherapy treatments.

Dendritic Cells in Cancer Immunology and Immunotherapy.

Cancer immunotherapy modulates the immune system, overcomes immune escape and stimulates immune defenses against tumors. Dendritic cells (DCs) are professional promoters of immune responses against tumor antigens with the outstanding ability to coordinate the innate and adaptive immune systems. Evidence suggests that there is a decrease in both the number and function of DCs in cancer patients. Therefore, they represent a strong scaffold for therapeutic interventions. DC vaccination (DCV) is safe, and the antitumoral responses induced are well established in solid tumors. Although the addition of checkpoint inhibitors (CPIs) to chemotherapy has provided new options in the treatment of cancer, they have shown no clinical benefit in immune desert tumors or in those tumors with dysfunctional or exhausted T-cells. In this way, DC-based therapy has demonstrated the ability to modify the tumor microenvironment for immune enriched tumors and to potentiate systemic host immune responses as an active approach to treating cancer patients. Application of DCV in cancer seeks to obtain long-term antitumor responses through an improved T-cell priming by enhancing previous or generating de novo immune responses. To date, DCV has induced immune responses in the peripheral blood of patients without a significant clinical impact on outcome. Thus, improvements in vaccines formulations, selection of patients based on biomarkers and combinations with other antitumoral therapies are needed to enhance patient survival. In this work, we review the role of DCV in different solid tumors with their strengths and weaknesses, and we finally mention new trends to improve the efficacy of this immune strategy.

CD137 (4-1BB) requires physically associated cIAPs for signal transduction and antitumor effects.

CD137 (4-1BB) is a member of the TNFR family that mediates potent T cell costimulatory signals upon ligation by CD137L or agonist monoclonal antibodies (mAbs). CD137 agonists attain immunotherapeutic antitumor effects in cancer mouse models, and multiple agents of this kind are undergoing clinical trials. We show that cIAP1 and cIAP2 are physically associated with the CD137 signaling complex. Moreover, cIAPs are required for CD137 signaling toward the NF-κB and MAPK pathways and for costimulation of human and mouse T lymphocytes. Functional evidence was substantiated with SMAC mimetics that trigger cIAP degradation and by transfecting cIAP dominant-negative variants. Antitumor effects of agonist anti-CD137 mAbs are critically dependent on the integrity of cIAPs in cancer mouse models, and cIAPs are also required for signaling from CARs encompassing CD137's cytoplasmic tail.

PSA reactivity in extracellular microvesicles to commercial immunoassays.

AIMS: Characterization of PSA in extracellular microvesicles (EVs) and its reactivity to commercial methods. MATERIALS AND METHODS: EVs derived from serum of 47 prostate cancer (PCa) patients, 27 benign prostatic hyperplasia (BPH) patients and 42 healthy controls were analyzed. EVs isolation and quantification of PSA immunoreactive to total (ev-T-PSA) or free (ev-F-PSA) PSA immunoassays, were performed using commercial assays. PSA in CD81+ or CD63+ EVs was determined directly in serum by an immunocapture-ELISA (IC-ELISA). RESULTS: Ev-T-PSA immunoreactive to Elecsys assay was detected in all samples. Median T-PSA ev/srm ratio was 2.20 % (Q1-Q3: 0.80-4.00 %), although in some samples this ratio reached 59 %. T-PSA ev/srm ratio was higher in those samples with serum T-PSA below 4 µg/L than in those exceeding that cut-off (p < 0.001). T-PSA ev/srm ratio was lower in PCa patients compared to healthy controls and BPH patients (p < 0.001). Elecsys immunoassays detected higher concentrations of ev-T-PSA and ev-F-PSA than Immulite (p < 0.001). PSA was detected by IC-ELISA more intensely in CD81+ EVs than in CD63+ EVs, and ev-T-PSA correlated with PSA+ CD63+ (p < 0.001) but not with PSA+ CD81+. CONCLUSION: EVs-bound PSA is another form of circulating PSA whose measurement could be easily performed in clinical laboratories by automated immunoassays.

Heterogenous presence of neutrophil extracellular traps in human solid tumours is partially dependent on IL-8.

Neutrophil extracellular traps (NETs) are webs of extracellular nuclear DNA extruded by dying neutrophils infiltrating tissue. NETs constitute a defence mechanism to entrap and kill fungi and bacteria. Tumours induce the formation of NETs to the advantage of the malignancy via a variety of mechanisms shown in mouse models. Here, we investigated the presence of NETs in a variety of human solid tumours and their association with IL-8 (CXCL8) protein expression and CD8+ T-cell density in the tumour microenvironment. Multiplex immunofluorescence panels were developed to identify NETs in human cancer tissues by co-staining with the granulocyte marker CD15, the neutrophil marker myeloperoxidase and citrullinated histone H3 (H3Cit), as well as IL-8 protein and CD8+ T cells. Three ELISA methods to detect and quantify circulating NETs in serum were optimised and utilised. Whole tumour sections and tissue microarrays from patients with non-small cell lung cancer (NSCLC; n = 14), bladder cancer (n = 14), melanoma (n = 11), breast cancer (n = 31), colorectal cancer (n = 20) and mesothelioma (n = 61) were studied. Also, serum samples collected retrospectively from patients with metastatic melanoma (n = 12) and NSCLC (n = 34) were ELISA assayed to quantify circulating NETs and IL-8. NETs were detected in six different human cancer types with wide individual variation in terms of tissue density and distribution. At least in NSCLC, bladder cancer and metastatic melanoma, NET density positively correlated with IL-8 protein expression and inversely correlated with CD8+ T-cell densities. In a series of serum samples from melanoma and NSCLC patients, a positive correlation between circulating NETs and IL-8 was found. In conclusion, NETs are detectable in formalin-fixed human biopsy samples from solid tumours and in the circulation of cancer patients with a considerable degree of individual variation. NETs show a positive association with IL-8 and a trend towards a negative association with CD8+ tumour-infiltrating lymphocytes. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Five Year Survival Update From KEYNOTE-010: Pembrolizumab Versus Docetaxel for Previously Treated, Programmed Death-Ligand 1-Positive Advanced NSCLC.

INTRODUCTION: In the KEYNOTE-010 study, pembrolizumab improved overall survival (OS) versus docetaxel in patients with previously treated, advanced NSCLC with programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) ≥50% and ≥1%. We report 5-year efficacy and safety follow-up for the KEYNOTE-010 study. METHODS: Patients were randomized to pembrolizumab 2 mg/kg or 10 mg/kg once every 3 weeks or docetaxel 75 mg/m2 once every 3 weeks for up to 35 cycles (2 y). Patients who completed pembrolizumab treatment and subsequently had recurrence could receive second-course pembrolizumab for up to 17 cycles (1 y). Pembrolizumab doses were pooled in this analysis. RESULTS: A total of 1034 patients were randomized (pembrolizumab, n = 691; docetaxel, n = 343). Median study follow-up was 67.4 months (range: 60.0‒77.9). The hazard ratio (95% confidence interval) for OS was 0.55 (0.44‒0.69) for patients with PD-L1 TPS ≥50% and 0.70 (0.61‒0.80) with PD-L1 TPS ≥1%. The 5-year OS rates for pembrolizumab versus docetaxel were 25.0% versus 8.2% in patients with PD-L1 TPS ≥50% and 15.6% versus 6.5% with PD-L1 TPS ≥1%. Among 79 patients who completed 35 cycles/2 years of pembrolizumab, the OS rate 3 years after completion (∼5 y from randomization) was 83.0%. A total of 21 patients received second-course pembrolizumab; 11 (52.4%) had an objective response after starting the second course and 15 (71.4%) were alive at data cutoff. Exploratory biomarker analysis revealed that higher tissue tumor mutational burden (≥175 mutations per exome) was associated with improved outcomes with pembrolizumab. CONCLUSIONS: Pembrolizumab continued to provide long-term benefit than docetaxel in patients with previously treated advanced NSCLC with PD-L1 TPS ≥50% and ≥1%. Our findings confirm pembrolizumab as a standard-of-care treatment in the second-line or later setting.

Differential Interleukin-8 thresholds for chemotaxis and netosis in human neutrophils.

In humans, IL-8 (CXCL8) is a key chemokine for chemotaxis of polymorphonuclear leukocytes and monocytes/macrophages when acting on CXCR1 and CXCR2. CXCL8 activity on neutrophils includes chemotaxis and eliciting the extrusion of neutrophil extracellular traps (NETs). In this study, we show that concentrations of IL-8 that induce NETosis surpass in at least one order of magnitude those required to elicit chemoattraction in human neutrophils. IL-8-induced NETosis was less dependent on G-proteins than migration, while extracellular Ca+2 chelation similarly inhibited both processes. Reactive oxygen species (ROS) were more important for NETosis than for chemotaxis as evidenced by neutralization with N-acetyl -cysteine. Interestingly, selective blockade with anti-CXCR1 mAb inhibited NETosis much more readily than chemotaxis, while pharmacological inhibition of both CXCR1 and CXCR2, or selective inhibition for CXCR2 alone, similarly inhibited both functions. Together, these results propose a model according to which low concentrations of IL-8 in a gradient attract neutrophils to the inflammatory foci, while high receptor-saturating concentrations of IL-8 give rise to NETosis once leukocytes reach the core of the inflammatory insult.

Paradigms on Immunotherapy Combinations with Chemotherapy.

Checkpoint inhibitors are being added to standard-of-care chemotherapy in multiple clinical trials. Success has been reported in non-small and small cell lung carcinomas and urothelial, head and neck, gastric, and esophageal cancers, and promising results are already available in triple-negative breast and pancreatic malignancies. The potential mechanisms of synergy include immunogenic tumor cell death, antiangiogenesis, selective depletion of myeloid immunosuppressive cells, and lymphopenia, which reduces regulatory T cells and makes room for proliferation of effector T cells. However, chemotherapy regimens have not been optimized for such combinations, perhaps explaining some recent clinical trial disappointments. Approaches to make the most of chemoimmunotherapy include neoadjuvant and adjuvant schemes.Significance: Immunotherapy of cancer based on PD-1/PD-L1 blockade has prompted a revolution in cancer clinical management. Evidence in phase III clinical trials already supports combinations of immunotherapy with standard-of-care chemotherapy for a number of malignant diseases. This review focuses on such evidence and provides an overview of the potential synergistic mechanisms of action and the opportunities to optimize chemoimmunotherapy regimens.

Partial Response and Stable Disease Correlate with Positive Outcomes in Atezolizumab-treated Patients with Advanced Urinary Tract Carcinoma.

BACKGROUND: The value of a complete response to immune checkpoint inhibitor treatment for urothelial cancer is well recognised, but less is known about long-term outcomes in patients with a partial response or the benefit of achieving disease stabilisation. OBJECTIVE: To determine clinical outcomes in patients with a partial response or stable disease on atezolizumab therapy for advanced urinary tract carcinoma (UTC). DESIGN, SETTING, AND PARTICIPANTS: Data were extracted from three prospective trials (IMvigor210 cohort 2, SAUL, and IMvigor211) evaluating single-agent atezolizumab therapy for platinum-pretreated advanced UTC. The analysis population included 604 atezolizumab-treated and 208 chemotherapy-treated patients (229 achieving a partial response and 583 achieving stable disease). INTERVENTION: Atezolizumab 1200 mg every 3 wk until progression or unacceptable toxicity or single-agent chemotherapy for patients in the control arm of IMvigor211. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline characteristics, treatment exposure, overall survival, duration of disease control. Partial response and stable disease populations were analysed separately. RESULTS AND LIMITATIONS: The population of patients with a partial response included more patients with programmed cell death ligand 1 (PD-L1) expression on ≥5% of tumour-infiltrating immune cells than the stable disease population. The median time to best response was 2.1 mo across trials and treatments, regardless of the type of response. Atezolizumab-treated patients with a partial response had sustained disease control (median overall survival not reached); durations of disease control and overall survival were longer with atezolizumab than with chemotherapy. In patients with stable disease, median overall survival was numerically longer with atezolizumab (exceeding 1 yr) than with chemotherapy. Irrespective of treatment, durations of disease control and survival were shorter in patients with stable disease than in those achieving a partial response. These analyses are limited by their post hoc exploratory nature and relatively short follow-up. CONCLUSIONS: Stable disease and partial response are meaningful clinical outcomes in atezolizumab-treated patients with advanced UTC. PATIENT SUMMARY: In this report, we looked at the outcomes in patients whose tumours responded to treatment to some extent, but the tumour did not disappear completely. We aimed to understand whether a modest response to treatment was associated with meaningful long-term outcomes for patients. We found that on average, life expectancy was >1 yr in patients whose disease was stabilised and even longer in those whose tumours showed some shrinkage in response to treatment.

Performance comparison of two next-generation sequencing panels to detect actionable mutations in cell-free DNA in cancer patients.

Background Genomic alterations studies in cell-free DNA (cfDNA) have increasing clinical use in oncology. Next-generation sequencing (NGS) technology provides the most complete mutational analysis, but nowadays limited data are available related to the comparison of results reported by different platforms. Here we compare two NGS panels for cfDNA: Oncomine™ Pan-Cancer Cell-Free Assay (Thermo Fisher Scientific), suitable for clinical laboratories, and Guardant360® (GuardantHealth), with more genes targeted but only available in an outsourcing laboratory. Methods Peripheral blood was obtained from 16 advanced cancer patients in which Guardant360® (G360) was requested as part of their clinical assistance. Blood samples were sent to be analyzed with G360 panel, and an additional blood sample was drawn to obtain and analyze cfDNA with Oncomine™ Pan-Cancer (OM) panel in an Ion GeneStudio S5™ System. Results cfDNA analysis globally rendered 101 mutations. Regarding the 55/101 mutations claimed to be included by manufacturers in both panels, 17 mutations were reported only by G360, 10 only by OM and 28 by both. In those coincident cases, there was a high correlation between the variant allele fractions (VAFs) calculated with each panel (r = 0.979, p < 0.01). Regarding the six actionable mutations with an FDA-approved therapy reported by G360, one was missed with OM. Also, 12 mutations with clinical trials available were reported by G360 but not by OM. Conclusions In summary, G360 and OM can produce different mutational profile in the same sample, even in genes included in both panels, which is especially important if these mutations are potentially druggable.

CXCR1 and CXCR2 Chemokine Receptor Agonists Produced by Tumors Induce Neutrophil Extracellular Traps that Interfere with Immune Cytotoxicity.

Neutrophils are expanded and abundant in cancer-bearing hosts. Under the influence of CXCR1 and CXCR2 chemokine receptor agonists and other chemotactic factors produced by tumors, neutrophils, and granulocytic myeloid-derived suppressor cells (MDSCs) from cancer patients extrude their neutrophil extracellular traps (NETs). In our hands, CXCR1 and CXCR2 agonists proved to be the major mediators of cancer-promoted NETosis. NETs wrap and coat tumor cells and shield them from cytotoxicity, as mediated by CD8+ T cells and natural killer (NK) cells, by obstructing contact between immune cells and the surrounding target cells. Tumor cells protected from cytotoxicity by NETs underlie successful cancer metastases in mice and the immunotherapeutic synergy of protein arginine deiminase 4 (PAD4) inhibitors, which curtail NETosis with immune checkpoint inhibitors. Intravital microscopy provides evidence of neutrophil NETs interfering cytolytic cytotoxic T lymphocytes (CTLs) and NK cell contacts with tumor cells.

Long-Term Outcomes and Retreatment Among Patients With Previously Treated, Programmed Death-Ligand 1‒Positive, Advanced Non‒Small-Cell Lung Cancer in the KEYNOTE-010 Study.

PURPOSE: In the KEYNOTE-010 study, pembrolizumab improved overall survival (OS) versus docetaxel in previously treated, programmed death-ligand 1 (PD-L1)‒expressing advanced non‒small-cell lung cancer (NSCLC) in patients with a tumor proportion score (TPS) ≥ 50% and ≥ 1%. We report KEYNOTE-010 long-term outcomes, including after 35 cycles/2 years or second-course pembrolizumab. METHODS: Of 1,033 patients randomly assigned (intention to treat), 690 received up to 35 cycles/2 years of pembrolizumab 2 mg/kg (n = 344) or 10 mg/kg (n = 346) every 3 weeks, and 343 received docetaxel 75 mg/m2 every 3 weeks. Eligible patients with disease progression after 35 cycles/2 years of pembrolizumab could receive second-course treatment (up to 17 cycles). Pembrolizumab doses were pooled because no between-dose difference was observed at primary analysis. RESULTS: Pembrolizumab continued to improve OS over docetaxel in the PD-L1 TPS ≥ 50% and ≥ 1% groups (hazard ratio [HR], 0.53; 95% CI, 0.42 to 0.66; P < .00001; and HR, 0.69; 95% CI, 0.60 to 0.80; P < .00001, respectively) after a 42.6-month (range, 35.2-53.2 months) median follow-up. Estimated 36-month OS rates were 34.5% versus 12.7% and 22.9% versus 11.0%, respectively. Grade 3-5 treatment-related adverse events occurred in 16% versus 37% of patients, respectively. Seventy-nine of 690 patients completed 35 cycles/2 years of pembrolizumab; 12-month OS and progression-free survival rates after completing treatment were 98.7% (95% CI, 91.1% to 99.8%) and 72.5% (95% CI, 59.9% to 81.8%), respectively. Seventy-five patients (95%) had objective response (RECIST v1.1, blinded independent central review) and 48 (64%) had ongoing response. Grade 3-5 treatment-related adverse events occurred in 17.7% of patients. Fourteen patients received second-course pembrolizumab: 5 completed 17 cycles, 6 (43%) had partial response, and 5 (36%) had stable disease. CONCLUSION: Pembrolizumab provided long-term OS benefit over docetaxel, with manageable safety, durable responses among patients receiving 2 years of treatment, and disease control with second-course treatment, further supporting pembrolizumab for previously treated, PD-L1‒expressing advanced NSCLC.

Short-term starvation reduces IGF-1 levels to sensitize lung tumors to PD-1 immune checkpoint blockade.

Harnessing the immune system by blocking the programmed cell death protein 1 (PD-1) pathway has been a major breakthrough in non-small-cell lung cancer treatment. Nonetheless, many patients fail to respond to PD-1 inhibition. Using three syngeneic models, we demonstrate that short-term starvation synergizes with PD-1 blockade to inhibit lung cancer progression and metastasis. This antitumor activity was linked to a reduction in circulating insulin-like growth factor 1 (IGF-1) and a downregulation of IGF-1 receptor (IGF-1R) signaling in tumor cells. A combined inhibition of IGF-1R and PD-1 synergistically reduced tumor growth in mice. This effect required CD8 cells, boosted the intratumoral CD8/Treg ratio and led to the development of tumor-specific immunity. In patients with non-small-cell lung cancer, high plasma levels of IGF-1 or high IGF-1R expression in tumors was associated with resistance to anti-PD-1-programmed death-ligand 1 immunotherapy. In conclusion, our data strongly support the clinical evaluation of IGF-1 modulators in combination with PD-1 blockade.

Immunotherapeutic effects of intratumoral nanoplexed poly I:C.

Poly I:C is a powerful immune adjuvant as a result of its agonist activities on TLR-3, MDA5 and RIG-I. BO-112 is a nanoplexed formulation of Poly I:C complexed with polyethylenimine that causes tumor cell apoptosis showing immunogenic cell death features and which upon intratumoral release results in more prominent tumor infiltration by T lymphocytes. Intratumoral treatment with BO-112 of subcutaneous tumors derived from MC38, 4 T1 and B16-F10 leads to remarkable local disease control dependent on type-1 interferon and gamma-interferon. Some degree of control of non-injected tumor lesions following BO-112 intratumoral treatment was found in mice bearing bilateral B16-OVA melanomas, an activity which was enhanced with co-treatment with systemic anti-CD137 and anti-PD-L1 mAbs. More abundant CD8+ T lymphocytes were found in B16-OVA tumor-draining lymph nodes and in the tumor microenvironment following intratumoral BO-112 treatment, with enhanced numbers of tumor antigen-specific cytotoxic T lymphocytes. Genome-wide transcriptome analyses of injected tumor lesions were consistent with a marked upregulation of the type-I interferon pathway. Inspired by these data, intratumorally delivered BO-112 is being tested in cancer patients (NCT02828098).

The Dynamic Use of EGFR Mutation Analysis in Cell-Free DNA as a Follow-Up Biomarker during Different Treatment Lines in Non-Small-Cell Lung Cancer Patients.

Epidermal growth factor receptor (EGFR) mutational testing in advanced non-small-cell lung cancer (NSCLC) is usually performed in tumor tissue, although cfDNA (cell-free DNA) could be an alternative. We evaluated EGFR mutations in cfDNA as a complementary tool in patients, who had already known EGFR mutations in tumor tissue and were treated with either EGFR-tyrosine kinase inhibitors (TKIs) or chemotherapy. We obtained plasma samples from 21 advanced NSCLC patients with known EGFR tumor mutations, before and during therapy with EGFR-TKIs and/or chemotherapy. cfDNA was isolated and EGFR mutations were analyzed with the multiple targeted cobas EGFR Mutation Test v2. EGFR mutations were detected at baseline in cfDNA from 57% of patients. The semiquantitative index (SQI) significantly decreased from the baseline (median = 11, IQR = 9.5-13) to the best response (median = 0, IQR = 0-0, p < 0.01), followed by a significant increase at progression (median = 11, IQR = 11-15, p < 0.01) in patients treated with either EGFR-TKIs or chemotherapy. The SQI obtained with the cobas EGFR Mutation Test v2 did not correlate with the concentration in copies/mL determined by droplet digital PCR. Resistance mutation p.T790M was observed at progression in patients with either type of treatment. In conclusion, cfDNA multiple targeted EGFR mutation analysis is useful for treatment monitoring in tissue of EGFR-positive NSCLC patients independently of the drug received.

Neoadjuvant nivolumab modifies the tumor immune microenvironment in resectable glioblastoma.

Glioblastoma is the most common primary central nervous system malignancy and has a poor prognosis. Standard first-line treatment, which includes surgery followed by adjuvant radio-chemotherapy, produces only modest benefits to survival1,2. Here, to explore the feasibility, safety and immunobiological effects of PD-1 blockade in patients undergoing surgery for glioblastoma, we conducted a single-arm phase II clinical trial (NCT02550249) in which we tested a presurgical dose of nivolumab followed by postsurgical nivolumab until disease progression or unacceptable toxicity in 30 patients (27 salvage surgeries for recurrent cases and 3 cases of primary surgery for newly diagnosed patients). Availability of tumor tissue pre- and post-nivolumab dosing and from additional patients who did not receive nivolumab allowed the evaluation of changes in the tumor immune microenvironment using multiple molecular and cellular analyses. Neoadjuvant nivolumab resulted in enhanced expression of chemokine transcripts, higher immune cell infiltration and augmented TCR clonal diversity among tumor-infiltrating T lymphocytes, supporting a local immunomodulatory effect of treatment. Although no obvious clinical benefit was substantiated following salvage surgery, two of the three patients treated with nivolumab before and after primary surgery remain alive 33 and 28 months later.

TGFß Blockade Enhances Radiotherapy Abscopal Efficacy Effects in Combination with Anti-PD1 and Anti-CD137 Immunostimulatory Monoclonal Antibodies.

Radiotherapy can be synergistically combined with immunotherapy in mouse models, extending its efficacious effects outside of the irradiated field (abscopal effects). We previously reported that a regimen encompassing local radiotherapy in combination with anti-CD137 plus anti-PD-1 mAbs achieves potent abscopal effects against syngeneic transplanted murine tumors up to a certain tumor size. Knowing that TGFß expression or activation increases in irradiated tissues, we tested whether TGFß blockade may further enhance abscopal effects in conjunction with the anti-PD-1 plus anti-CD137 mAb combination. Indeed, TGFß blockade with 1D11, a TGFß-neutralizing mAb, markedly enhanced abscopal effects and overall treatment efficacy against subcutaneous tumors of either 4T1 breast cancer cells or large MC38 colorectal tumors. Increases in CD8 T cells infiltrating the nonirradiated lesion were documented upon combined treatment, which intensely expressed Granzyme-B as an indicator of cytotoxic effector capability. Interestingly, tumor tissue but not healthy tissue irradiation results in the presence of higher concentrations of TGFß in the nonirradiated contralateral tumor that showed smad2/3 phosphorylation increases in infiltrating CD8 T cells. In conclusion, radiotherapy-induced TGFß hampers abscopal efficacy even upon combination with a potent immunotherapy regimen. Therefore, TGFß blockade in combination with radioimmunotherapy results in greater efficacy.

Liquid Biopsy: From Basic Research to Clinical Practice.

Liquid biopsy refers to the molecular analysis in biological fluids of nucleic acids, subcellular structures, especially exosomes, and, in the context of cancer, circulating tumor cells. In the last 10 years, there has been an intensive research in liquid biopsy to achieve a less invasive and more precise personalized medicine. Molecular assessment of these circulating biomarkers can complement or even surrogate tissue biopsy. Because of this research, liquid biopsy has been introduced in clinical practice, especially in oncology, prenatal screening, and transplantation. Here we review the biology, methodological approaches, and clinical applications of the main biomarkers involved in liquid biopsy.

Radium-223 international early access program: results from the Spanish subset.

AIM: To report results from the Spanish subset included in the radium-223 international early access program (iEAP). PATIENTS & METHODS: Ninety patients with castration-resistant prostate cancer and bone metastases received radium-223 55 kBq/kg every 4 weeks for six cycles. RESULTS: The median time to disease progression was 8 months and to prostate-specific antigen progression was 4 months. The percentage of patients with ≥50% confirmed declines in prostate-specific antigen was 9%. The median overall survival was 14 months. Grade 3 or 4 treatment emergent adverse events (TEAEs) occurred in 34% of patients (serious TEAEs 28%, TEAEs leading to discontinuation 27%). CONCLUSION: Outcomes of the Spanish subset are consistent with the iEAP. Radium-223 was generally well tolerated with no safety concerns.

Interleukin-8 in cancer pathogenesis, treatment and follow-up.

Interleukin-8 (CXCL8) was originally described asa chemokine whose main function is the attraction of a polymorphonuclear inflammatory leukocyte infiltrate acting on CXCR1/2. Recently, it has been found that tumors very frequently coopt the production of this chemokine, which in this malignant context exerts different pro-tumoral functions. Reportedly, these include angiogenesis, survival signaling for cancer stem cells and attraction of myeloid cells endowed with the ability to immunosuppress and locally provide growth factors. Given the fact that in cancer patients IL-8 is mainly produced by tumor cells themselves, its serum concentration has been shown to correlate with tumor burden. Thus, IL-8 serum concentrations have been shown to be useful asa pharmacodynamic biomarker to early detect response to immunotherapy. Finally, because of the roles that IL-8 plays in favoring tumor progression, several therapeutic strategies are being developed to interfere with its functions. Such interventions hold promise, especially for therapeutic combinations in the field of cancer immunotherapy.