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Background: Low-dose CT (LDCT) screening trials have shown that lung cancer early detection saves lives. However, a better stratification of the screening population is still needed. In this respect, we generated and prospectively validated a plasma miRNA signature classifier (MSC) able to categorize screening participants according to lung cancer risk. Here, we aimed to deeply characterize the peripheral immune profile and develop a diagnostic immune signature classifier to further implement blood testing in lung cancer screening. Methods: Peripheral blood mononuclear cell (PBMC) samples collected from 20 patients with LDCT-detected lung cancer and 20 matched cancer-free screening volunteers were analyzed by flow cytometry using multiplex panels characterizing both lymphoid and myeloid immune subsets. Data were validated in PBMC from 40 patients with lung cancer and 40 matched controls and in a lung cancer specificity set including 27 subjects with suspicious lung nodules. A qPCR-based gene expression signature was generated resembling selected immune subsets. Results: Monocytic myeloid-derived suppressor cell (MDSC), polymorphonuclear MDSC, intermediate monocytes and CD8+PD-1+ T cells distinguished patients with lung cancer from controls with AUCs values of 0.94/0.72/0.88 in the training, validation, and lung cancer specificity set, respectively. AUCs raised up to 1.00/0.84/0.92 in subgroup analysis considering only MSC-negative subjects. A 14-immune genes expression signature distinguished patients from controls with AUC values of 0.76 in the validation set and 0.83 in MSC-negative subjects. Conclusions: An immune-based classifier can enhance the accuracy of blood testing, thus supporting the contribution of systemic immunity to lung carcinogenesis. Impact: Implementing LDCT screening trials with minimally invasive blood tests could help reduce unnecessary procedures and optimize cost-effectiveness.

Supplementary Methods

Supplementary Tables S1-S6_S17-S18

Supplementary Figures

In tumor-bearing mice, cyclic fasting or fasting-mimicking diets (FMD) enhance the activity of antineoplastic treatments by modulating systemic metabolism and boosting antitumor immunity. Here we conducted a clinical trial to investigate the safety and biological effects of cyclic, five-day FMD in combination with standard antitumor therapies. In 101 patients, the FMD was safe, feasible, and resulted in a consistent decrease of blood glucose and growth factor concentration, thus recapitulating metabolic changes that mediate fasting/FMD anticancer effects in preclinical experiments. Integrated transcriptomic and deep-phenotyping analyses revealed that FMD profoundly reshapes anticancer immunity by inducing the contraction of peripheral blood immunosuppressive myeloid and regulatory T-cell compartments, paralleled by enhanced intratumor Th1/cytotoxic responses and an enrichment of IFNγ and other immune signatures associated with better clinical outcomes in patients with cancer. Our findings lay the foundations for phase II/III clinical trials aimed at investigating FMD antitumor efficacy in combination with standard antineoplastic treatments.Significance:Cyclic FMD is well tolerated and causes remarkable systemic metabolic changes in patients with different tumor types and treated with concomitant antitumor therapies. In addition, the FMD reshapes systemic and intratumor immunity, finally activating several antitumor immune programs. Phase II/III clinical trials are needed to investigate FMD antitumor activity/efficacy.This article is highlighted in the In This Issue feature, p. 1

Supplementary Table S7-S16

PDF file - 85K, Supplementary Figure S2.Representation of the results of the class comparison analysis of the gene expression data. In total, 3,078 genes were differentially expressed in the PP samples compared with all other SNBs. In the analysis, 333 genes were differentially expressed between the PN and the PP tumor-positive SNB samples, 58 genes were differentially expressed between all tumor-positive SNBs and the N samples, and 18 genes were differentially expressed between the PN and N samples.

Supplementary Figure 1 from CCN3/Nephroblastoma Overexpressed Matricellular Protein Regulates Integrin Expression, Adhesion, and Dissemination in Melanoma

XLSX file - 202K, Supplementary Table S3. Results generated by GSEA comparing the PN and the PP samples.

XLSX file - 132K, Supplementary Table S5.CD30 expression in the PP.

XLSX file - 15K, Supplementary Table S1.Clinicopathological data for the SNB samples analyzed in the training and validation studies.

PDF file - 107K, Supplementary Figure S3.Comparative gene expression analysis by qRT-PCR of the genes that were differently expressed between the PP and the PN groups. A. Genes upregulated in the PP samples (DEFA1, IL17B, and CST6) (p

PDF file - 68K, Supplementary Figure S1.Expression levels of melanoma genes in the SNB samples, as indicated by the array data. The genes and SNB groups are indicated, and the intensity values (minimum to maximum) and the median are shown. The values for the PN or PP samples in comparison with the N samples are indicated (*, p

Sentinel lymph nodes set the stance of the immune system to a localized tumor and are often the first site to be colonized by neoplastic cells that metastasize. To investigate how the presence of neoplastic cells in sentinel lymph nodes may trigger pathways associated with metastatic progression, we analyzed the transcriptional profiles of archival sentinel node biopsy specimens obtained from melanoma patients. Biopsies from positive nodes were selected for comparable tumor infiltration, presence or absence of further regional node metastases, and relapse at 5-year follow-up. Unsupervised analysis of gene expression profiles revealed immune response to be a major gene ontogeny represented. Among genes upregulated in patients with progressing disease, the TNF receptor family member CD30/TNFRSF8 was confirmed in biopsy specimens from an independent group of patients. Immunohistochemical analysis revealed higher numbers of CD30+ lymphocytes in nodes from progressing patients compared with nonprogressing patients. Phenotypic profiling demonstrated that CD30+ lymphocytes comprised a broad population of suppressive or exhausted immune cells, such as CD4+Foxp3+ or PD1+ subpopulations and CD4−CD8− T cells. CD30+ T lymphocytes were increased in peripheral blood lymphocytes of melanoma patients at advanced disease stages. Our findings reinforce the concept that sentinel nodes act as pivotal sites for determining progression patterns, revealing that the presence of CD30+ lymphocytes at those sites associate positively with melanoma progression. Cancer Res; 74(1); 130–40. ©2014 AACR.

XLSX file - 2088K, Supplementary Table S2.Differentially expressed gene lists.

CCN3/nephroblastoma overexpressed belongs to the CCN family of genes that encode secreted proteins associated with the extracellular matrix (ECM) and exert regulatory effects at the cellular level. Overexpression of CCN3 was shown in metastatic melanoma cells compared with cells of the primary tumor from the same patient. Analysis of short-term cultures from 50 primary and metastatic melanomas revealed a heterogeneous expression pattern of both the 46-kDa full-length cytoplasmic/secreted protein and the 32-kDa nuclear-truncated form. The different protein expression patterns were not associated with gene alterations or polymorphisms. Like the metastatic cells expressing high levels of the 46-kDa CCN3, cells transfected to overexpress CCN3 showed increased adhesion to ECM proteins, whereas inhibition of CCN3 expression by small interfering RNA decreased adhesion to laminin and vitronectin. CCN3 overexpression induced increased expression of laminin and vitronectin integrin receptors α7β1 and αvβ5 by increasing their mRNA production. Moreover, CCN3 secreted by melanoma cells acted as an adhesion matrix protein for melanoma cells themselves. Analysis of CCN3 protein expression with respect to melanoma progression detected the protein in all visceral metastases tested and in most nodal metastases from relapsing patients but in only a few nodal metastases from nonrelapsing patients and cutaneous metastases. Consistently, xenotransplantation in immunodeficient mice showed a higher metastatic potential of melanoma cells overexpressing CCN3. Together, these data indicate a role for CCN3 in melanoma cell interaction with the ECM by regulating integrin expression, resulting in altered cell adhesion and leading melanoma progression to aggressive disease. [Cancer Res 2008;68(3):715–23]

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XLSX file - 198K, Supplementary Table S4. Genes found to be differentially expressed between the PP and the PN samples, as confirmed by qPCR.

Supplementary Methods, Figure 1 Legend , Tables 1-2 from CCN3/Nephroblastoma Overexpressed Matricellular Protein Regulates Integrin Expression, Adhesion, and Dissemination in Melanoma

Background Outcomes of patients with metastatic melanoma discontinuing BRAF‐targeted therapy for cumulative toxicity after sustained response are unknown. Materials and Methods This retrospective case series analysis conducted at a single Cancer Center in Italy included patients with BRAF mutated metastatic melanoma treated with a BRAF inhibitor as a single agent or in combination with a MEK inhibitor between June 1, 2011 and January 1, 2020 and interrupted treatment due to cumulative toxicity after achieving complete response (CR) or long‐lasting partial response (PR; i.e. >12 months). Results We included 24 patients with a median treatment duration of 59.4 months (95% confidence interval [CI], 55.4–63.4; range, 12–88). CR and PR were achieved in 71% and 29% of patients, respectively. At a median follow‐up after treatment discontinuation of 37.8 months (95% CI, 33.7–41.9), the 12‐month progression‐free survival after discontinuation (dPFS) rate was 70.8% (95% CI 54.8–91.6) and 24‐month dPFS rate was 58.3% (95% CI, 41.6–81.8). Baseline patient and tumor characteristics as well as treatment duration and best response did not significantly impact on dPFS. Patients with CR and negative circulating tumor DNA (ctDNA) at time of discontinuation had a significantly improved dPFS compared with patients with either radiological residual disease or ctDNA positivity (p = .007). No patient in CR with undetectable ctDNA experienced progression. Conclusion The risk of progression is high even in patients with sustained sensitivity to BRAF/MEK inhibitors. Integration of liquid biopsy in clinical trials investigating the optimal management of patients with sustained sensitivity to BRAF/MEK inhibitors is warranted. Implications for Practice Outcomes of patients with metastatic melanoma discontinuing BRAF‐targeted therapy for cumulative toxicity are unknown. This study analyzed patients with sustained responses (median treatment duration 59.4 months). Twelve‐ and 24‐month progression‐free survival following discontinuation were 70.8% and 58.3%, respectively. Complete response and negative circulating tumor DNA at time of discontinuation are promising prognostic biomarkers in this setting., This article reports clinical outcomes of patients with metastatic melanoma treated with BRAF/MEK inhibitors who interrupted the treatment after achieving a long‐lasting objective response, exploring the role of circulating tumor DNA assessed at time of discontinuation as a biomarker for post‐discontinuation progression‐free survival.

This study aimed at unravelling whether WDLPS undergo a progressive evolution to DDLPS through analyzing the transcriptomic profile of retroperitoneal liposarcoma. In a contemporary retrospective series of primary retroperitoneal DDLPS and WDLPS (N=107), we sampled paired DD/WD/normal fat (NF) components of DDLPS and paired WD/NF components of WDLPS. RNA-Seq data was normalized using the trimmed mean of M-value (TMM) algorithm, heteroscedasticity was removed, and differential expression analysis (DEA) performed. Gene sets enrichment analysis (GSEA) evaluated enrichment in biological hallmarks and was performed to overcome FDR correction of DEA and evaluate the ensemble. FDR threshold 0.05 was considered for significance. Marked transcriptional changes exist among paired components of DDLPS (DD, WD, NF) or WDLPS (WD, NF). Although DEA did not show significant changes between WD and NF components of DDLPS and WDLPS, GSEA analysis highlighted deregulation in hallmarks. An upregulation of G2M checkpoint and mitotic spindle gene sets was observed when WD components of DDLPS was compared to WDLPS and progressively increase in the DD component. Some targetable genes from the leading edge of these pathways (PLK1, AURKA, and EZH2) as well as the primary oncogenic drivers (MDM2, CDK4, and HMGA2) of liposarcoma were functionally validated with targeted agents in cell lines of DDLPS and WDLPS, supporting findings of transcriptomic analysis. We also observed that adipogenesis, fatty acid metabolism, cholesterol homeostasis, oxidative phosphorylation, and peroxisome gene sets were down-regulated in the DD component, while glycolysis was upregulated compared to WD components. When NF were compared with their paired tumor components, G2M checkpoint and mitotic spindle gene sets did not differ between DDLPS and WDLPS, suggesting these two hallmarks as tumor-specific. NF of patients with DDLPS demonstrated higher expression of adipogenesis, and other pathways related to metabolism suggesting its metabolic activation compared to NF of patients with WDLPS. In conclusion, changes distinguishing WDLPS/DDLPS early at the WD stage and progressively increasing in the DD component of DDLPS supported the hypothesis of an orderly progression from WDLPS to DDLPS and represent a source of additional therapeutic targets. Citation Format: Sandro Pasquali, Stefano Percio, Dario Callegaro, Silvia Martini, Alessia Beretta, Alessia Bertolotti, Silvia Brich, Paola Collini, Marta Barisella, Loris De Cecco, Viviana Vallacchi, Silvia Stacchiotti, Matteo Benelli, Alessandro Gronchi, Nadia Zaffaroni. The transcriptomic profile of retroperitoneal primary well differentiated liposarcoma (WDLPS) and well differentiated (WD)/dedifferentiated (DD) components of DD liposarcoma (DDLPS) reveals the progression from WDLPS to DDLPS [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2245.

TPS754 Background: Collecting duct carcinoma (CDC) is a rare type of non-clear cell renal cell carcinoma with an aggressive course and poor prognosis. The treatment of metastatic disease remains unsatisfactory as no standard-of-care has been established yet. The gap in the clinical management is certainly linked to the poor molecular characterization. To date, a comprehensive biological characterization of CDC and the identification of predictive biomarker is still lacking. Our previous studies proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signalling, metabolic and immune-related alterations and featured by a prognostic signature associating T cell immunity and angiogenesis with good clinical outcome and sensitivity to cabozantinib (Gargiuli et al, Cancers 2021 Jun 10;13(12):2903; Todoerti et al, J Clin Oncol 40, no. 16_suppl (June 01, 2022) e16507-e16507; Verzoni et al, Ann Oncol 33:S1218-S121). The aim of CICERONE trial is to change the paradigm of CDC management providing therapies in a biologically informed manner starting from our previous findings. Methods: First, we will define a molecular taxonomy of CDC through comprehensive transcriptomic profiling of 100 CDC samples retrospectively collected within 12 months from the Italian Group of Uropathology Network and the European Union Hub Center. Pathologic review by genitourinary pathologist was required. RNA-Seq will be performed. Results will be merged to that already obtained by the same methodology from the BONSAI dataset (NCT03354884) and evaluated by unsupervised clustering analysis. We will identify differentially expressed genes and pathways. The immune and angiogenic signatures will be searched validating our preliminary results to identify predictive signatures for the subsequent prospective phase II trial. RNA-seq data will be also explored to detect fusion transcripts, as potential source of novel CDC oncogenic drivers, and study immune tumor content through Cybersort deconvolution. RT-qPCR on RNA derived from tumor and normal tissue will be performed to determine tumor specific origin of the fusion transcripts. Immune infiltrate will be also characterized by IHC, together with PDL-1 scoring. Subsequently we will conduct a prospective phase II trial in order to optimize treatment choice and validate prospectively the biological data. In this phase, previously untreated patients with metastatic CDC will be treated according to baseline tumor signature. Moreover, we will assess whether a new concept of immune liquid biopsy that includes the assessment of immunosuppressive vs antitumor immune cells may represent an accessible and compliant tool to test systemic immunity and its implications in response to treatment. This study was supported by the Italian Ministry of health (RF-2019-12369602). Clinical trial information: NCT05372302 .

The MITF-E318K variant has been implicated in genetic predisposition to cutaneous melanoma. We addressed the occurrence of MITF-E318K and its association with germline status of CDKN2A and MC1R genes in a hospital-based series of 248 melanoma patients including cohorts of multiple, familial, pediatric, sporadic and melanoma associated with other tumors. Seven MITF-E318K carriers were identified, spanning every group except the pediatric patients. Three carriers showed mutated CDKN2A, five displayed MC1R variants, while the sporadic carrier revealed no variants. Germline/tumor whole exome sequencing for this carrier revealed germline variants of unknown significance in ATM and FANCI genes and, in four BRAF-V600E metastases, somatic loss of the MITF wild-type allele, amplification of MITF-E318K and deletion of a 9p21.3 chromosomal region including CDKN2A and MTAP. In silico analysis of tumors from MITF-E318K melanoma carriers in the TCGA Pan-Cancer-Atlas dataset confirmed the association with BRAF mutation and 9p21.3 deletion revealing a common genetic pattern. MTAP was the gene deleted at homozygous level in the highest number of patients. These results support the utility of both germline and tumor genome analysis to define tumor groups providing enhanced information for clinical strategies and highlight the importance of melanoma prevention programs for MITF-E318K patients.

The genetic landscape of melanoma resistance to targeted therapy with small molecules inhibiting BRAF and MEK kinases is still largely undefined. In this study, we portrayed in detail the somatic alterations of resistant melanoma and explored the associated biological processes and their integration with transcriptional profiles. By targeted next-generation sequencing and whole-exome sequencing analyses, a list of 101 genes showing imbalance in metastatic tumors from patients with a complete/durable response or disease progression during therapy with vemurafenib or with dabrafenib and trametinib was defined. Classification of altered genes in functional categories indicated that the mutational pattern of both resistant tumors and melanoma cell lines was enriched in gene families involved in oncogenic signaling pathways and in DNA repair. Integration of genomic and transcriptomic features showed that the enrichment of mutations in gene sets associated with anabolic processes, chromatin alterations, and IFN-α response determined a significant positive modulation of the same gene signatures at the transcriptional level. In particular, MTORC1 signaling was enriched in tumors from poorly responsive patients and in resistant tumors excised from treated patients. Results indicate that genetic patterns are associated with melanoma resistance to targeted therapy and disclose the underlying key molecular pathways to define drug combinations for improved personalized therapies.

To what extent extracellular vesicles (EVs) can impact anti-tumor immune responses has only started to get unraveled. Their nanometer dimensions, their growing number of subtypes together with the difficulties in defining their origin hampers their investigation. The existence of tumor cell lines facilitated advance in cancer EV understanding, while capturing information about phenotypes and functions of immune cell EVs in this context is more complex. The advent of immunotherapy with immune checkpoint inhibitors has further deepened the need to dissect the impact of EVs during immune activation and response, not least to contribute unraveling and preventing the generation of resistance occurring in the majority of patients. Here we discuss the factors that influence/drive the immune response in cancer patients in the context of cancer therapeutics and the roles or possible functions EVs can have in this scenario. With immune cell-derived EVs as leitmotiv we will journey from EV discovery and subtypes through their physiological and pathological non-cancer functions to their similarities with cancer EVs and on how to revert their detrimental consequences on immune responses to cancer.

Soft tissue sarcomas (STSs) are a family of rare malignant tumors encompassing more than 80 histologies. Current therapies for metastatic STS, a condition that affects roughly half of patients, have limited efficacy, making innovative therapeutic strategies urgently needed. From a molecular point of view, STSs can be classified as translocation-related and those with a heavily rearranged genotype. Although only the latter display an increased mutational burden, molecular profiles suggestive of an “immune hot” tumor microenvironment are observed across STS histologies, and response to immunotherapy has been reported in both translocation-related and genetic complex STSs. These data reinforce the notion that immunity in STSs is multifaceted and influenced by both genetic and epigenetic determinants. Cumulative evidence indicates that a fine characterization of STSs at different levels is required to identify biomarkers predictive of immunotherapy response and to discover targetable pathways to switch on the immune sensitivity of “immune cold” tumors. In this review, we will summarize recent findings on the interplay between genetic landscape, molecular profiling and immunity in STSs. Immunological and molecular features will be discussed for their prognostic value in selected STS histologies. Finally, the local and systemic immunomodulatory effects of the targeted drugs imatinib and sunitinib will be discussed.

In tumor-bearing mice, cyclic fasting or fasting-mimicking diets (FMD) enhance the activity of antineoplastic treatments by modulating systemic metabolism and boosting antitumor immunity. Here we conducted a clinical trial to investigate the safety and biological effects of cyclic, five-day FMD in combination with standard antitumor therapies. In 101 patients, the FMD was safe, feasible, and resulted in a consistent decrease of blood glucose and growth factor concentration, thus recapitulating metabolic changes that mediate fasting/FMD anticancer effects in preclinical experiments. Integrated transcriptomic and deep-phenotyping analyses revealed that FMD profoundly reshapes anticancer immunity by inducing the contraction of peripheral blood immunosuppressive myeloid and regulatory T-cell compartments, paralleled by enhanced intratumor Th1/cytotoxic responses and an enrichment of IFNγ and other immune signatures associated with better clinical outcomes in patients with cancer. Our findings lay the foundations for phase II/III clinical trials aimed at investigating FMD antitumor efficacy in combination with standard antineoplastic treatments. Significance: Cyclic FMD is well tolerated and causes remarkable systemic metabolic changes in patients with different tumor types and treated with concomitant antitumor therapies. In addition, the FMD reshapes systemic and intratumor immunity, finally activating several antitumor immune programs. Phase II/III clinical trials are needed to investigate FMD antitumor activity/efficacy. This article is highlighted in the In This Issue feature, p. 1

Immunotherapy with immune checkpoint inhibitors can achieve long-term tumor control in subsets of patients. However, its effect can be blunted by myeloid-induced resistance mechanisms. Myeloid cells are highly plastic and physiologically devoted to wound healing and to immune homeostasis maintenance. In cancer, their physiological activities can be modulated, leading to an expansion of pro-inflammatory and immunosuppressive cells, the myeloid-derived suppressor cells (MDSCs), with detrimental consequences. The involvement of MDSCs in tumor development and progression has been widely investigated and MDSC-induced immunosuppression is acknowledged as a mechanism hindering effective immune checkpoint blockade. Small non-coding RNA molecules, the microRNAs (miRs), contribute to myeloid cell regulation at different levels, comprising metabolism and function, as well as their skewing to a MDSC phenotype. miR expression can be indirectly induced by cancer-derived factors or through direct miR import via extracellular vesicles. Due to their structural stability and their presence in body fluids miRs represent promising predictive biomarkers of resistance, as we recently found by investigating plasma samples of melanoma patients undergoing immune checkpoint blockade. Dissection of the miR-driven involved mechanisms would pave the way for the identification of new druggable targets. Here, we discuss the role of these miRs in shaping myeloid resistance to immunotherapy with a special focus on immunosuppression and immune escape.

BackgroundRescue of exhausted T cell immunity through the inhibition of PD-1/PD-L1 interaction is a pillar of immunotherapeutic anti-PD-1 monoclonal antibodies (mAbs), as Nivolumab and Pembrolizumab. Despite the IgG4 subclass, anti-PD-1 mAbs can bind different FcγRs and trigger immunosuppressive activity in FcR-expressing myeloid cells. This effect is evident when anti-PD-1 mAbs engage soluble PD-1 (sPD-1) forming a stable sPD-1-antiPD-1mAb immune complex (PD-1 IC). In the present study we dissect the process by investigating which of the FcγRs displays the highest affinity for monomeric or complexed Nivolumab. In addition, methods for detecting and quantifying PD-1 ICs in plasma of patients treated with PD-1 blockers mAbs are under development for clinical application.MethodsBy surface plasmon resonance (SRP) (BiacoreTM T200, Cytiva), the interaction of FcγRI/CD64, FcγRIIa/CD32a, FcγRIIb/CD32b, FcγRIIIa/CD16a and FcγRIIIb/CD16b with anti-PD1 Nivolumab and the corresponding PD-1-IC has been evaluated, and their cellular localization has been assessed by confocal microscopy. Further, sPD-1 and PD-1 IC has been determined by customized ELISAs and western blot approaches in plasma of anti-PD-1 mAb-treated patients.ResultsThe binding of anti-PD1 and PD-1-IC occurred with all the FcγRs tested, albeit sensorgrams revealed diverse degrees of affinity. No major difference in the overall affinity of the monomeric anti-PD-1 versus PD-1 IC is observed for FcγRI/CD64, FcγRIIa/CD32a, FcγRIIb/CD32b. Instead, the dissociation phase was clearly slowest for PD-1 IC with respect to the monomeric mAb in FcγRIIIa/CD16a and FcγRIIIb/CD16b binding studies. Nevertheless, only PD-1 IC undergoes internalization when interacting with human FcγR+ myeloid cells in vitro, through pathways that does not appear to lead to lysosomal co-localization. Customized ELISA for PD-1 IC quantification has been developed to detect the complex after enrichment of plasma IgG4 by specific matrix. Data concerning the evaluation of PD-1 IC concentration in plasma of cancer patients treated with Nivolumab, will be presented.ConclusionsDespite the IgG4 subclass is expected to display the lowest binding affinity to Fcγs, we report here that anti-PD-1 therapeutic antibodies bind significantly to CD16, CD32 and CD64, particularly if stabilized in the IC form by engaging soluble PD-1. This evidence, if occurring in vivo, could introduce novel functional properties to these therapeutic agents, with potential detrimental effects on their clinical efficacy. Our findings imply that tools to antagonize PD-1-related exhaustion by Fc-null mAbs or non-mAb-based strategies could be preferred to engage full-fledged antitumor immune responses without unwanted effects related to FcR triggering.

BackgroundDesmoid fibromatosis (DF) is a locally aggressive rare tumor with high recurrence rate after surgery and unpredictable clinical course. Standard of care for DF patients is active surveillance; however, 30% of patients will progress and need active treatments. Biomarkers discriminating aggressive forms of DF are not available and prediction of progressing patients remains challenging. DF harbors mutations in β-catenin and a transcriptional ‘inflammatory phenotype’. Cancer-associated inflammation is fostered by systemic factors and detectable in circulating immune cells. Blood leukocytes thus represent a promising source of prognostic biomarkers for DF patients. In this study we investigate phenotypic and functional features of peripheral blood immune cells and molecular profile of DF biopsies to identify DF patients at risk of progression and guide tailored therapeutic approaches.MethodsThis is a prospective observational study enrolling patients with primary sporadic desmoid fibromatosis under active surveillance (n=80). Tumor and blood samples collected at diagnosis and during active surveillance will be studied by 1. transcriptomic analysis of DF biopsies; 2. multiparametric flowcytometry and functional profiling of blood cells; 3. RNA profiling of whole blood; 4. evaluation of plasma levels of cyto/chemokine and ctDNA of β-catenin variants. Levels of blood analytes will be correlated with patients‘ clinical outcome and integrated with immunological parameters.ResultsPeripheral blood immune profile of 42 cases and 17 healthy donors (HD) shows that DF patients display at baseline an altered myeloid profile compared to HD, which is maintained in a subset of patients during the first year of active surveillance. An increase in immunosuppressive activated granulocytes and granulocytic myeloid-derived suppressor cells, defined by differential co-expression of CD15, CD11b, CD16 and LOX1, is observed, concomitantly, with a boost of monocyte subsets, defined by co-expression of CD33, CD11b, CD14, CD16, HLA-DR and PDL1. Immunosuppressive low density granulocytes are increased in progressing patients compared to HD and regressors. Of note, a significant up-regulation of immunosuppressive PMN-MDSC (defined as CD15+LOX-1+) is observed in DF harboring T41A mutation, but not in S45 mutated DF.Transcriptomic data of DF biopsies and of plasma analytes are ongoing.ConclusionsSystemic alterations of immunosuppressive and inflammatory myeloid cell subsets in peripheral blood of DF patients indicate that the inflammatory status detected at tumor site is reflected at systemic level. The altered myeloid profile supports the involvement of the immune system in DF onset and may represent a marker of disease aggressiveness.AcknowledgementsSupported by Italian Ministry of Health (RF-2016-02362609).Trial RegistrationNot applicable.ReferencesNot applicable.Ethics ApprovalThe study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Ethics Committee of Fondazione IRCCS Istituto Nazionale dei Tumori di Milano (protocol code INT85/10).ConsentWritten informed consent was obtained from the patient for publication of this abstract. A copy of the written consent is available for review by the Editor of this journal.

Methods for phenotype and outcome prediction are largely based on inductive supervised models that use selected biomarkers to make predictions, without explicitly considering the functional relationships between individuals. We introduce a novel network-based approach named Patient-Net (P-Net) in which biomolecular profiles of patients are modeled in a graph-structured space that represents gene expression relationships between patients. Then a kernel-based semi-supervised transductive algorithm is applied to the graph to explore the overall topology of the graph and to predict the phenotype/clinical outcome of patients. Experimental tests involving several publicly available datasets of patients afflicted with pancreatic, breast, colon and colorectal cancer show that our proposed method is competitive with state-of-the-art supervised and semi-supervised predictive systems. Importantly, P-Net also provides interpretable models that can be easily visualized to gain clues about the relationships between patients, and to formulate hypotheses about their stratification.

It has been for long conceived that hallmarks of cancer were intrinsic genetic features driving tumor development, proliferation, and progression, and that targeting such cell-autonomous pathways could be sufficient to achieve therapeutic cancer control. Clinical ex vivo data demonstrated that treatment efficacy often relied on the contribution of host immune responses, hence introducing the concept of tumor microenvironment (TME), namely the existence, along with tumor cells, of non-tumor components that could significantly influence tumor growth and survival. Among the complex network of TME-driving forces, immunity plays a key role and the balance between antitumor and protumor immune responses is a major driver in contrasting or promoting cancer spreading. TME is usually a very immunosuppressed milieu because of a vast array of local alterations contrasting antitumor adaptive immunity, where metabolic changes contribute to cancer dissemination by impairing T cell infiltration and favoring the accrual and activation of regulatory cells. Subcellular structures known as extracellular vesicles then help spreading immunosuppression at systemic levels by distributing genetic and protein tumor repertoire in distant tissues. A major improvement in the knowledge of TME is now pointing the attention back to tumor cells; indeed, recent findings are showing how oncogenic pathways and specific mutations in tumor cells can actually dictate the nature and the function of immune infiltrate. As our information on the reciprocal interactions regulating TME increases, finding a strategy to interfere with TME crosstalk becomes more complex and challenging. Nevertheless, TME interactions represent a promising field for the discovery of novel biomarkers and therapeutic targets for improving treatment efficacy in cancer.

[Background] Extraskeletal myxoid chondrosarcoma is a rare sarcoma with low sensitivity to cytotoxic chemotherapy. Retrospective evidence suggests that antiangiogenic drugs could be a treatment option. We aimed to investigate the activity of pazopanib, an antiangiogenic drug, in patients with advanced extraskeletal myxoid chondrosarcoma., [Methods] In this single-arm, open-label phase 2 trial, three parallel independent cohorts of different histotypes of advanced sarcomas were recruited (extraskeletal myxoid chondrosarcoma, typical solitary fibrous tumour, and malignant-dedifferentiated solitary fibrous tumour). In each cohort, patients received pazopanib. In this Article, we report the results of the cohort of patients with advanced extraskeletal myxoid chondrosarcoma. Separate reporting of the three cohorts was prespecified in the study protocol. In this cohort, adult patients (aged ≥18 years) with a diagnosis of NR4A3-translocated, metastatic, or unresectable extraskeletal myxoid chondrosarcoma, who had Response Evaluation Criteria in Solid Tumors (RECIST) progression in the previous 6 months, and had an Eastern Cooperative Oncology Group performance status of 0–2, were enrolled at 11 study sites of the Spanish, Italian, and French sarcoma groups. Patients received oral pazopanib (800 mg/day) continuously, until disease progression, unacceptable toxicity, death, non-compliance, patient refusal, or investigator's decision. The primary endpoint was the proportion of patients achieving an objective response according to RECIST 1·1 in the modified intention-to-treat population (patients who provided consent and had a central molecularly confirmed diagnosis of extraskeletal myxoid chondrosarcoma). The safety analysis included all patients who received at least one dose of pazopanib. This study is registered with ClinicalTrials.gov, number NCT02066285., [Findings] Between June 24, 2014, and Jan 17, 2017, 26 patients entered the study and started pazopanib. Of these, 23 met the eligibility criteria for the modified intention-to-treat analysis. Median follow-up was 27 months (IQR 18–30). 22 patients (one patient died before the primary analysis) were evaluable for the primary endpoint: four (18% [95% CI 1–36]) had a RECIST objective response. No deaths or grade 4 adverse events occurred. The most frequent grade 3 adverse events were hypertension (nine [35%] of 26 patients), increased concentration of alanine aminotransferase (six [23%]), and increased aspartate aminotransferase (five [19%])., [Interpretation] Pazopanib had clinically meaningful antitumour activity in patients with progressive and advanced extraskeletal myxoid chondrosarcoma, and could be considered a suitable option after failure to respond to first-line anthracycline-based chemotherapy in these patients., Funding: Spanish Group for Research on Sarcomas, Italian Sarcoma Group, French Sarcoma Group, GlaxoSmithKline, and Novartis.

The accrual of myeloid-derived suppressor cells (MDSCs) represents a major obstacle to effective immunotherapy in cancer patients, but the mechanisms underlying this process in the human setting remain elusive. Here, we describe a set of microRNAs (miR-146a, miR-155, miR-125b, miR-100, let-7e, miR-125a, miR-146b, miR-99b) that are associated with MDSCs and resistance to treatment with immune checkpoint inhibitors in melanoma patients. The miRs were identified by transcriptional analyses as being responsible for the conversion of monocytes into MDSCs (CD14(+)HLA-DR(neg) cells) mediated by melanoma extracellular vesicles (EVs) and were shown to recreate MDSC features upon transfection. In melanoma patients, these miRs were increased in circulating CD14(+) monocytes, plasma, and tumor samples, where they correlated with the myeloid cell infiltrate. In plasma, their baseline levels clustered with the clinical efficacy of CTLA-4 or programmed cell death protein 1 (PD-1) blockade. Hence, MDSC-related miRs represent an indicator of MDSC activity in cancer patients and a potential blood marker of a poor immunotherapy outcome.

719 Background: Patients (pts) displaying a full-fledged immune response show high levels of circulating extracellular vesicles (EVs) containing immune transcripts that might be transferred to neighboring cells to amplify immune responses, as in autoimmunity and transplantation. We hypothesized EV immune transcripts could reflect immune activation in cancer pts receiving immunotherapy with immune checkpoint inhibitors (ICI). These RNA-containing EVs may surrogate immune functionality and represent a plasma transcriptional signature of adaptive immunity that can be readily detected by liquid biopsy. Methods: Blood samples from metastatic renal cell cancer pts,treated with ICI nivolumab (n=8) or tyrosine kinase inhibitor cabozantinib (n=9) were collected at baseline, week 4 and 12. EV-RNA was isolated from plasma with membrane affinity spin columns and evaluated for CD274(PD-L1), IFNG, PDCD1 (PD-1), CD3 and GZMB (granzyme B) transcripts by qRT-PCR. Results: All pts showed a statistically significant increase of CD3, IFNG, GZMB, PD-1 and PD-L1 immune transcripts in plasma EVs, evidenced at 4 and 12 weeks of therapy. Treatment subgroup analysis revealed an upregulation of CD3, IFNG, GZMB and PD-1 transcripts only in plasma EVs of patients receiving nivolumab that was more evident in those showing clinical benefit (4/8), while PD-L1 increased significantly during cabozantinib treatment. Upon comparing transcripts with soluble proteins, PD-L1 displayed similar kinetics, while PD-1 increased only as transcript but not as protein, given its potential sequestration by the anti-PD-1 antibody. This effect was detectable only in nivolumab but not in cabozantinib treated pts. Conclusions: Monitoring immune transcripts carried by plasma EVs holds promise as potential tool to assess the entity of the ongoing immune activation during immunotherapy. Plasma EVs may be exploited as indicators of immune response and help to predict clinical efficacy at early on-treatment time points. This approach based on plasma EVs might represent a starting point for the development of a novel strategy to study immune responses in clinical setting.

Sentinel lymph nodes set the stance of the immune system to a localized tumor and are often the first site to be colonized by neoplastic cells that metastasize. To investigate how the presence of neoplastic cells in sentinel lymph nodes may trigger pathways associated with metastatic progression, we analyzed the transcriptional profiles of archival sentinel node biopsy specimens obtained from melanoma patients. Biopsies from positive nodes were selected for comparable tumor infiltration, presence or absence of further regional node metastases, and relapse at 5-year follow-up. Unsupervised analysis of gene expression profiles revealed immune response to be a major gene ontogeny represented. Among genes upregulated in patients with progressing disease, the TNF receptor family member CD30/TNFRSF8 was confirmed in biopsy specimens from an independent group of patients. Immunohistochemical analysis revealed higher numbers of CD30+ lymphocytes in nodes from progressing patients compared with nonprogressing patients. Phenotypic profiling demonstrated that CD30+ lymphocytes comprised a broad population of suppressive or exhausted immune cells, such as CD4+Foxp3+ or PD1+ subpopulations and CD4−CD8− T cells. CD30+ T lymphocytes were increased in peripheral blood lymphocytes of melanoma patients at advanced disease stages. Our findings reinforce the concept that sentinel nodes act as pivotal sites for determining progression patterns, revealing that the presence of CD30+ lymphocytes at those sites associate positively with melanoma progression. Cancer Res; 74(1); 130–40. ©2014 AACR.

Sentinel node biopsy (SNB) is a main staging biomarker in melanoma and is the first lymph node to drain the tumor, thus representing the immunological site where anti-tumor immune dysfunction is established and where potential prognostic immune markers can be identified. Here we analyzed microRNA (miR) profiles in archival tumor-positive SNBs derived from melanoma patients with different outcomes and performed an integrated analysis of transcriptional data to identify deregulated immune signaling networks. Twenty-six miRs were differentially expressed in melanoma-positive SNB samples between patients with disease progression and non-progressing patients, the majority being previously reported in the regulation of immune responses. A significant variation in miR expression levels was confirmed in an independent set of SNB samples. Integrated information from genome-wide transcriptional profiles and in vitro assessment in immune cells led to the identification of miRs associated with the regulation of the TNF receptor superfamily member 8 (TNFRSF8) gene encoding the CD30 receptor, a marker increased in lymphocytes of melanoma patients with progressive disease. These findings indicate that miRs are involved in the regulation of pathways leading to immune dysfunction in the sentinel node and may provide valuable markers for developing prognostic molecular signatures for the identification of stage III melanoma patients at risk of recurrence.

PLX4032/vemurafenib is a first-in-class small-molecule BRAFV600E inhibitor with clinical activity in patients with BRAF mutant melanoma. Nevertheless, drug resistance develops in treated patients, and strategies to overcome primary and acquired resistance are required. To explore the molecular mechanisms involved in primary resistance to PLX4032, we investigated its effects on cell proliferation and signaling in a panel of 27 genetically characterized patient-derived melanoma cell lines. Cell sensitivity to PLX4032 was dependent on BRAFV600E and independent from other gene alterations that commonly occur in melanoma such as PTEN loss, BRAF, and MITF gene amplification. Two cell lines lacking sensitivity to PLX4032 and harboring a different set of genetic alterations were studied as models of primary resistance. Treatment with the MEK inhibitor UO126 but not with PLX4032 inhibited cell growth and ERK activation. Resistance to PLX4032 was maintained after CRAF down-regulation by siRNA indicating alternative activation of MEK-ERK signaling. Genetic characterization by multiplex ligation-dependent probe amplification and analysis of phosphotyrosine signaling by MALDI-TOF mass spectrometry analysis revealed the activation of MET and SRC signaling, associated with the amplification of MET and of CTNNB1 and CCND1 genes, respectively. The combination of PLX4032 with drugs or siRNA targeting MET was effective in inhibiting cell growth and reducing cell invasion and migration in melanoma cells with MET amplification; similar effects were observed after targeting SRC in the other cell line, indicating a role for MET and SRC signaling in primary resistance to PLX4032. Our results support the development of classification of melanoma in molecular subtypes for more effective therapies.

It is increasingly clear that melanoma cells modify their environment not only through the release of growth factors (GFs) and cytokines that have autocrine or paracrine effects and strongly modulate the immune response, but also by secreting proteins that become structural or transient components of the extracellular matrix (ECM). Melanoma cell secreted proteins play a significant role in cell-ECM interactions, helping tumor cells to invade neighbouring stroma, disseminate and survive in other tissue contexts. CCN3/NOV (nephroblastoma overexpressed) is a matricellular protein that belongs to the CCN family of proteins containing six members in humans. Its structure consists of modules related to functional domains previously identified in major regulatory proteins: insulin-like growth factor-binding protein (IGFBP), von Willebrand factor type C repeats (VWC), thrombospondin type 1 repeats, and secreted regulatory factors containing cysteine knot motifs. Extensive studies have indicated that the biological properties of CCN3 are dependent upon the cellular context, and its role in melanoma seems to recapitulate cell context functions.