PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD-1 blockade

BACKGROUND

Uterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some 'challenging-to-treat' cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB.

METHODS

We performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient-derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single-agent and a combination of PI3K/mTOR inhibitors with PD-1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single-cell RNA/TCR sequencing of serially collected biopsies.

RESULTS

PI3K/mTOR over-activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB-resistant humanized uLMS PDX model, fostering adaptive anti-tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti-tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD-1+ T cells displaying an exhausted phenotype. When combined with anti-PD-1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single-agent anti-PD-1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper-expansion of a cytotoxic CD8+ T-cell population supported by a CD4+ Th1 niche.

CONCLUSIONS

Our findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.

An autophagy program that promotes T cell egress from the lymph node controls responses to immune checkpoint blockade

Lymphatic endothelial cells (LECs) of the lymph node (LN) parenchyma orchestrate leukocyte trafficking and peripheral T cell dynamics. T cell responses to immunotherapy largely rely on peripheral T cell recruitment in tumors. Yet, a systematic and molecular understanding of how LECs within the LNs control T cell dynamics under steady-state and tumor-bearing conditions is lacking. Intravital imaging combined with immune phenotyping shows that LEC-specific deletion of the essential autophagy gene Atg5 alters intranodal positioning of lymphocytes and accrues their persistence in the LNs by increasing the availability of the main egress signal sphingosine-1-phosphate. Single-cell RNA sequencing of tumor-draining LNs shows that loss of ATG5 remodels niche-specific LEC phenotypes involved in molecular pathways regulating lymphocyte trafficking and LEC-T cell interactions. Functionally, loss of LEC autophagy prevents recruitment of tumor-infiltrating T and natural killer cells and abrogates response to immunotherapy. Thus, an LEC-autophagy program boosts immune-checkpoint responses by guiding systemic T cell dynamics.

The Clinical Relevance of the Infiltrating Immune Cell Composition in Kidney Transplant Rejection

Key Points

Background

The link between the histology of kidney transplant rejection, especially antibody-mediated rejection, T-cell–mediated rejection, and mixed rejection, and the types of infiltrating immune cells is currently not well charted. Cost and technical complexity of single-cell analysis hinder large-scale studies of the relationship between cell infiltrate profiles and histological heterogeneity.

Methods

In this cross-sectional study, we assessed the composition of nine intragraft immune cell types by using a validated kidney transplant–specific signature matrix for deconvolution of bulk transcriptomics in three different kidney transplant biopsy datasets (N=403, N=224, N=282). The association and discrimination of the immune cell types with the Banff histology and the association with graft failure were assessed individually and with multivariable models. Unsupervised clustering algorithms were applied on the overall immune cell composition and compared with the Banff phenotypes.

Results

Banff-defined rejection was related to high presence of CD8+ effector T cells, natural killer cells, monocytes/macrophages, and, to a lesser extent, B cells, whereas CD4+ memory T cells were lower in rejection compared with no rejection. Estimated intragraft effector memory–expressing CD45RA (TEMRA) CD8+ T cells were strongly and consistently associated with graft failure. The large heterogeneity in immune cell composition across rejection types prevented supervised and unsupervised methods to accurately recover the Banff phenotypes solely on the basis of immune cell estimates. The lack of correlation between immune cell composition and Banff-defined rejection types was validated using multiplex immunohistochemistry.

Conclusions

Although some specific cell types (FCGR3A + myeloid cells, CD14 + monocytes/macrophages, and NK cells) partly discriminated between rejection phenotypes, the overall estimated immune cell composition of kidney transplants was ill related to main Banff-defined rejection categories and added to the Banff lesion scoring and evaluation of rejection severity. The estimated intragraft CD8temra cells bore strong and consistent association with graft failure and were independent of Banff-grade rejection.

Qualitative Evaluation of a Pilot Physician Training Program in Long-Term Care Facilities in Switzerland

Increasing demand for long-term care facilities (LTCFs) and increasingly complex medical needs of LTCF residents necessitate recruiting new physician graduates and developing programs which provide them with experience and specific skills in geriatric and palliative medicine. We developed an educational program for physicians in training, which combines 1 year of immersion at 20% full-time equivalent with (1) theoretical teaching, (2) clinical exposure under the supervision of a senior LTCF physician, and (3) structured case presentations and debriefing with experienced geriatricians. This article presents a preliminary qualitative evaluation of this program from the perspectives of the trainees, supervising physicians, and public health stakeholders. The program was well accepted by all parties and showed positive effects on trainees' interest in long-term care medicine. Suggestions for improving future programs and their implementation are provided.

A TCF4-dependent gene regulatory network confers resistance to immunotherapy in melanoma

To better understand intrinsic resistance to immune checkpoint blockade (ICB), we established a comprehensive view of the cellular architecture of the treatment-naive melanoma ecosystem and studied its evolution under ICB. Using single-cell, spatial multi-omics, we showed that the tumor microenvironment promotes the emergence of a complex melanoma transcriptomic landscape. Melanoma cells harboring a mesenchymal-like (MES) state, a population known to confer resistance to targeted therapy, were significantly enriched in early on-treatment biopsies from non-responders to ICB. TCF4 serves as the hub of this landscape by being a master regulator of the MES signature and a suppressor of the melanocytic and antigen presentation transcriptional programs. Targeting TCF4 genetically or pharmacologically, using a bromodomain inhibitor, increased immunogenicity and sensitivity of MES cells to ICB and targeted therapy. We thereby uncovered a TCF4-dependent regulatory network that orchestrates multiple transcriptional programs and contributes to resistance to both targeted therapy and ICB in melanoma.

Tumor endothelial cell autophagy is a key vascular-immune checkpoint in melanoma

Tumor endothelial cells (TECs) actively repress inflammatory responses and maintain an immune-excluded tumor phenotype. However, the molecular mechanisms that sustain TEC-mediated immunosuppression remain largely elusive. Here, we show that autophagy ablation in TECs boosts antitumor immunity by supporting infiltration and effector function of T-cells, thereby restricting melanoma growth. In melanoma-bearing mice, loss of TEC autophagy leads to the transcriptional expression of an immunostimulatory/inflammatory TEC phenotype driven by heightened NF-kB and STING signaling. In line, single-cell transcriptomic datasets from melanoma patients disclose an enriched InflammatoryHigh /AutophagyLow TEC phenotype in correlation with clinical responses to immunotherapy, and responders exhibit an increased presence of inflamed vessels interfacing with infiltrating CD8+ T-cells. Mechanistically, STING-dependent immunity in TECs is not critical for the immunomodulatory effects of autophagy ablation, since NF-kB-driven inflammation remains functional in STING/ATG5 double knockout TECs. Hence, our study identifies autophagy as a principal tumor vascular anti-inflammatory mechanism dampening melanoma antitumor immunity.

Transcriptional and spatial profiling of the kidney allograft unravels a central role for FcyRIII+ innate immune cells in rejection

Rejection remains the main cause of premature graft loss after kidney transplantation, despite the use of potent immunosuppression. This highlights the need to better understand the composition and the cell-to-cell interactions of the alloreactive inflammatory infiltrate. Here, we performed droplet-based single-cell RNA sequencing of 35,152 transcriptomes from 16 kidney transplant biopsies with varying phenotypes and severities of rejection and without rejection, and identified cell-type specific gene expression signatures for deconvolution of bulk tissue. A specific association was identified between recipient-derived FCGR3A+ monocytes, FCGR3A+ NK cells and the severity of intragraft inflammation. Activated FCGR3A+ monocytes overexpressed CD47 and LILR genes and increased paracrine signaling pathways promoting T cell infiltration. FCGR3A+ NK cells overexpressed FCRL3, suggesting that antibody-dependent cytotoxicity is a central mechanism of NK-cell mediated graft injury. Multiplexed immunofluorescence using 38 markers on 18 independent biopsy slides confirmed this role of FcγRIII+ NK and FcγRIII+ nonclassical monocytes in antibody-mediated rejection, with specificity to the glomerular area. These results highlight the central involvement of innate immune cells in the pathogenesis of allograft rejection and identify several potential therapeutic targets that might improve allograft longevity.

Clinical, histopathological and molecular features of dedifferentiated melanomas: An EORTC Melanoma Group Retrospective Analysis

PURPOSE

Dedifferentiated melanoma (DedM) poses significant diagnostic challenges. We aimed to investigate the clinical, histopathological and molecular features of DedM. Methylation signature (MS) and copy number profiling (CNP) were carried out in a subgroup of cases.

PATIENTS AND METHODS

A retrospective series of 78 DedM tissue samples from 61 patients retrieved from EORTC (European Organisation for Research and Treatment of Cancer) Melanoma Group centres were centrally reviewed. Clinical and histopathological features were retrieved. In a subgroup of patients, genotyping through Infinium Methylation microarray and CNP analysis was carried out.

RESULTS

Most patients (60/61) had a metastatic DedM showing most frequently an unclassified pleomorphic, spindle cell, or small round cell morphology akin to undifferentiated soft tissue sarcoma, rarely associated with heterologous elements. Overall, among 20 successfully analysed tissue samples from 16 patients, we found retained melanoma-like MS in only 7 tissue samples while a non-melanoma-like MS was observed in 13 tissue samples. In two patients from whom multiple specimens were analysed, some of the samples had a preserved cutaneous melanoma MS while other specimens exhibited an epigenetic shift towards a mesenchymal/sarcoma-like profile, matching the histological features. In these two patients, CNP was largely identical across all analysed specimens, in line with their common clonal origin, despite significant modification of their epigenome.

CONCLUSIONS

Our study further highlights that DedM represents a real diagnostic challenge. While MS and genomic CNP may help pathologists to diagnose DedM, we provide proof-of-concept that dedifferentiation in melanoma is frequently associated with epigenetic modifications.

Multiomics and spatial mapping characterizes human CD8+ T cell states in cancer

Clinically relevant immunological biomarkers that discriminate between diverse hypofunctional states of tumor-associated CD8⁺ T cells remain disputed. Using multiomics analysis of CD8⁺ T cell features across multiple patient cohorts and tumor types, we identified tumor niche-dependent exhausted and other types of hypofunctional CD8⁺ T cell states. CD8⁺ T cells in "supportive" niches, like melanoma or lung cancer, exhibited features of tumor reactivity-driven exhaustion (CD8⁺ T_EX). These included a proficient effector memory phenotype, an expanded T cell receptor (TCR) repertoire linked to effector exhaustion signaling, and a cancer-relevant T cell-activating immunopeptidome composed of largely shared cancer antigens or neoantigens. In contrast, "nonsupportive" niches, like glioblastoma, were enriched for features of hypofunctionality distinct from canonical exhaustion. This included immature or insufficiently activated T cell states, high wound healing signatures, nonexpanded TCR repertoires linked to anti-inflammatory signaling, high T cell-recognizable self-epitopes, and an antiproliferative state linked to stress or prodeath responses. In situ spatial mapping of glioblastoma highlighted the prevalence of dysfunctional CD4⁺:CD8⁺ T cell interactions, whereas ex vivo single-cell secretome mapping of glioblastoma CD8⁺ T cells confirmed negligible effector functionality and a promyeloid, wound healing-like chemokine profile. Within immuno-oncology clinical trials, anti-programmed cell death protein 1 (PD-1) immunotherapy facilitated glioblastoma's tolerogenic disparities, whereas dendritic cell (DC) vaccines partly corrected them. Accordingly, recipients of a DC vaccine for glioblastoma had high effector memory CD8⁺ T cells and evidence of antigen-specific immunity. Collectively, we provide an atlas for assessing different CD8⁺ T cell hypofunctional states in immunogenic versus nonimmunogenic cancers.

Abstract 6773: Spatial dynamics of cytotoxic T lymphocyte exhaustion in reactive and tumoral tissue

Background The study of cytotoxic T-lymphocytes (Tcy) has shown increased attention from the scientific community in the last years because of their predictive role in anti-cancer therapy with specific interest in immune check point blocking therapy. However, most of these studies have used bulk or dissociation-based single-cell technologies to draw their biological insights. Lately, new spatial -omics technologies are increasing our knowledge on this population by adding the spatial location of these cells in-situ in the native structure of the tissue. In this study, we have compared the activation of Tcy in reactive and cancerous conditions at single cell level and in the micro-anatomical context of the tissue.

Experimental procedures One tissue micro array slide containing: reactive tonsil, inflammatory liver disease, breast cancer, glioblastoma and melanoma was stained using the COMET™ instrument (Lunaphore Technologies SA) for a multiplex panel of 20 markers. The derived multiplexed images were analyzed using the DISSCOVERY software platform developed by the MILAN Unit at KU Leuven (Belgium). 12/20 markers were specifically aimed at identifying the main cell populations in the tissue (CD11b, CD163, CD20, CD3, CD31, CD4, CD56, CD68, CD8, CK, FOXP3, S100) while the remaining 8 markers were aimed at adding functional information on immune cell types of interest (CD69, HLA-DR, Ki67, LAG3, OX40, PD-1, PD-L1, TIM3).

Results The general activation levels of the Tcy in the reactive conditions were higher than in the three cancer subtypes. When looking at Tcy activation as a function of the distance from the vascular structures (identified via CD31+ endothelial cells), we observed an orderly distribution of activated Tcy around CD31+ endothelial cells with a gradient of increasing exhaustion levels with increasing distance from the vessel in the reactive conditions. In the cancer samples, on the contrary, a patchy disorderly organized pattern of exhausted and activated Tcy was observed around the vessels.

Conclusion The spatial location of inflammatory cells plays a critical role to understand their functional behavior and thanks to technological progress it is now possible to start doing this at scale. The study of the dynamics of exhaustion of Tcy in the tissue will help clarify the interplay between cancer cells and immune environment. These results will be crucial to better select patients who may benefit the most of immune check point blockade.

Citation Format: Maxim De Schepper, Asier Antoranz, Nikolina Dubroja, Giuseppe Floris, Frederik De Smet, Francesca Bosisio. Spatial dynamics of cytotoxic T lymphocyte exhaustion in reactive and tumoral tissue. [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 6773.

Abstract A34: Therapeutic induction of High Endothelial Venules in cancer generates TCF1+ lymphocyte niches

The lack of T-cell infiltrates is a major obstacle to effective immunotherapy in cancer. Conversely, the formation of tumor-associated tertiary-lymphoid-like structures (TA-TLS), which are the local site of humoral and cellular immune responses against cancers, are associated with good prognosis and have recently been detected in Immune Checkpoint Blockade (ICB)-responding patients. However, how these lymphoid aggregates develop remains poorly understood. By employing scRNA sequencing, endothelial fate mapping, and multiplex immunohistochemistry, we demonstrate that antiangiogenic immune-modulating therapies evoke the transition of postcapillary venules into inflamed high endothelial venules (HEV), which predominantly generate permissive TA-TLS-like lymphocyte niches. These HEV+ immune niches entail PD1neg and PD1+TCF1+CD8+ progenitor cells that differentiate into cytotoxic TCF1neg TIM3+ PD1+ CD8 effector cells and migrate into the tumor core. Congruently, TU-HEV signatures correlate with response to ICB therapies in several human tumor types. In line with these observations, TU-HEVs require continuous CD8 and NK cell-derived lymphotoxin signals revealing that tumor-HEV maintenance is actively sculpted by the immune system through a feed-forward loop.

Citation Format: Gerlanda Vella, Yichao Hua, Florian Rambow, Elizabeth Allen, Asier Antoranz Martinez, Pascal Merchiers, Francesca Bosisio, Giuseppe Floris, Akira Takeda, Sirpa Jalkanen, Maija Hollmén, Jean-Christophe Marine, Susan Schlenner, Gabriele Bergers. Therapeutic induction of High Endothelial Venules in cancer generates TCF1+ lymphocyte niches [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A34.

A cellular hierarchy in melanoma uncouples growth and metastasis

Although melanoma is notorious for its high degree of heterogeneity and plasticity1,2, the origin and magnitude of cell-state diversity remains poorly understood. Equally, it is unclear whether growth and metastatic dissemination are supported by overlapping or distinct melanoma subpopulations. Here, by combining mouse genetics, single-cell and spatial transcriptomics, lineage tracing and quantitative modelling, we provide evidence of a hierarchical model of tumour growth that mirrors the cellular and molecular logic underlying the cell-fate specification and differentiation of the embryonic neural crest. We show that tumorigenic competence is associated with a spatially localized perivascular niche, a phenotype acquired through an intercellular communication pathway established by endothelial cells. Consistent with a model in which only a fraction of cells are fated to fuel growth, temporal single-cell tracing of a population of melanoma cells with a mesenchymal-like state revealed that these cells do not contribute to primary tumour growth but, instead, constitute a pool of metastatic initiating cells that switch cell identity while disseminating to secondary organs. Our data provide a spatially and temporally resolved map of the diversity and trajectories of melanoma cell states and suggest that the ability to support growth and metastasis are limited to distinct pools of cells. The observation that these phenotypic competencies can be dynamically acquired after exposure to specific niche signals warrant the development of therapeutic strategies that interfere with the cancer cell reprogramming activity of such microenvironmental cues.

HGG-56. Spatial mapping of the tumor micro-environment in pediatric glioma

High-grade glioma are the main cause of cancer-related death in children. The highly heterogeneous composition of the tumor cells and their interactions with the tumor micro-environment (TME), contribute substantially to the poor response to treatment and the high levels of morbidity and mortality. Here, we used high-dimensional, multiplexed immunohistochemistry to map the single-cell tissue architecture of 26 pediatric glioma samples covering 8 histologic diagnoses, allowing us to determine the spatial distribution of the various tumoral subtypes and how these interact with their local immune-microenvironment. Overall, this analysis showed that tumor grade anti-correlated with the amount of infiltrating cytotoxic T-lymphocytes (CTLs), which were typically more exhausted in the higher grade tumors. In addition, tumor associated macrophages were primarily infiltrating from the blood and presented an M2-like anti-inflammatory phenotype which became more extended with tumor grade. Using the spatial information, possible cell-cell interactions could be determined. In lower grade glioma, we observed an increased activation level of CTLs that were closely located to neighboring T-helper cells. In pediatric glioblastoma, on the other hand, CTLs, even though they were located close to a T-helper cell, could only minimally be activated, and showed more extended exhaustion when residing further away. Additionally, the activation of the CTLs was associated to the distance to the closest PD-L1 positive macrophage in pilocytic astrocytoma and desmoplastic infantile ganglioglioma. In conclusion, with the use of multiplex immunohistochemistry, we are able to study the tumor and TME of pediatric glioma in depth on a single-cell and spatial level, which allows us to further study the heterogeneous landscape of these tumors.

A case of Vaccine-Induced Thrombotic Thrombocytopenia (VITT) with thrombosis of the superior mesenteric artery after ChAdOx1 nCov-19 COVID-19 Vaccine

We describe the case of a 64 years-old woman admitted to the Emergency Department of the ASST-Spedali Civili of Brescia with fever and gastrointestinal symptoms 10 days after the first dose of ChAdOx1 nCov-19 vaccine. Laboratory investigations showed severe thrombocytopenia and high D-dimer, while an abdominal CT scan reported a partially occluding thrombosis of the superior mesenteric artery. Following treatment with fondaparinux, immunoglobulins and high dosage steroid therapy, we observed a rapid improvement of patient’s conditions. An ELISA assay showed the presence of antibodies against heparin PF4-complex. Subsequent abdominal CT-scan showed the superior mesenteric artery thrombosis resolution, and the patient was finally discharged after 12 days of hospitalization. Several reports pointed to the venous system as the main district affected by Vaccine-Induced Thrombotic Thrombocytopenia (VITT), while a peculiar feature of this report is the involvement of the mesenteric arterial system. Further investigation of VITT’s pathophysiological mechanisms is mandatory to develop preventive strategies and effective treatments.

Implementing advance care planning in early dementia care: results and insights from a pilot interventional trial

BACKGROUND

Advance care planning (ACP) is particularly appropriate for persons with early dementia (PWED) since it promotes conversations about dementia-specific illness scenarios, addresses inconsistencies between advance directives and patients' observed behavior, emphasizes prospective and relational autonomy, and may be generally consistent with older persons' decision-making needs. However, despite evidence of its benefits, ACP is yet to become widely used among PWED. In this paper, we present a dementia-specific tool developed in Western Switzerland, discuss results of a pilot trial designed to promote ACP among PWED and their relatives, and discuss the feasibility and acceptability of the intervention and the study protocol in prevision of a large scale trial.

METHODS

This one-arm pre-post pilot trial consisted of four visits, with visits 2 and 3 being the ACP intervention. Quantitative outcome measures during visit 1 and 4 assessed the aptitude of the intervention to support PWED autonomy and relatives' knowledge of PWED's preferences. Feasibility was explored according to how the recruitment procedure unfurled and based on the necessary revisions to the study protocol and healthcare providers' reason for excluding a PWED from the study. Acceptability was assessed according to pre-post evaluations, difficulties regarding the intervention or trial participation, and pre-post qualitative interviews regarding participants' reasons to participate to the study, satisfaction with the tool and difficulties perceived.

RESULTS

The ACP intervention itself was well received by PWED and their relatives that expressed satisfaction with the procedure, especially regarding the opportunity to discuss a sensitive topic with the help of a facilitator. Five main challenges in terms of feasibility were 1) to locate eligible patients, 2) to tailor recruitment procedures to recruitment locations, 3) to adapt inclusion criteria to clinical routines, 4) to engage PWED and their relatives in ACP, and 5) to design a trial that does not burden PWED. Despite these challenges, the intervention increased the number of advance directives, the concordance between PWED's preferences and relatives' decision on their behalf, and relatives' perceived control over healthcare decisions.

CONCLUSION

Misconceptions about dementia and ACP, in the patient, relatives, and healthcare providers, combined with structural and institutional challenges, have the power to impede research and implementation of ACP in dementia care. For this reason, we conclude that a large scale trial to test a dementia-specific tool of ACP is currently not feasible in Western Switzerland and should be endorsed in a systemic approach of ACP.

TRIAL REGISTRATION

This trial was registered in the database clinicaltrial.gov with the number NCT03615027 .

Evolutionary predictability of genetic versus nongenetic resistance to anticancer drugs in melanoma

Therapy resistance arises from heterogeneous drug-tolerant persister cells or minimal residual disease (MRD) through genetic and nongenetic mechanisms. A key question is whether specific molecular features of the MRD ecosystem determine which of these two distinct trajectories will eventually prevail. We show that, in melanoma exposed to mitogen-activated protein kinase therapeutics, emergence of a transient neural crest stem cell (NCSC) population in MRD concurs with the development of nongenetic resistance. This increase relies on a glial cell line-derived neurotrophic factor-dependent signaling cascade, which activates the AKT survival pathway in a focal adhesion kinase (FAK)-dependent manner. Ablation of the NCSC population through FAK inhibition delays relapse in patient-derived tumor xenografts. Strikingly, all tumors that ultimately escape this treatment exhibit resistance-conferring genetic alterations and increased sensitivity to extracellular signal-regulated kinase inhibition. These findings identify an approach that abrogates the nongenetic resistance trajectory in melanoma and demonstrate that the cellular composition of MRD deterministically imposes distinct drug resistance evolutionary paths.

Citizen Responses to Government Restrictions in Switzerland During the COVID-19 Pandemic: Cross-Sectional Survey

Background

The success of government-recommended mitigation measures during the COVID-19 pandemic depends largely on information uptake and implementation by individual citizens.

Objective

Our aim was to assess citizens’ knowledge and perceptions about COVID-19 recommendations in the Canton of Vaud, Switzerland.

Methods

A cross-sectional electronic survey with open and closed questions was disseminated by community-based partners prior to the relaxation of government restrictions. Outcomes included citizen knowledge (9-question measure) and worry about the virus, perception of government measures, and recommendations for improvements. Comparisons used linear regression, controlling for age, sex, education, and health literacy. Free-text answers were analyzed thematically.

Results

Of 807 people who accessed the survey, 684 (85%) completed all questions and 479 (60%) gave free-text recommendations. Overall, 75% were female, the mean age was 48 years, and 93% had high health literacy. Knowledge scores were high, with a median score of 8 out of 9. Mean levels of worry about the COVID-19 pandemic were higher in women than men (55/100 versus 44/100, P<.001), and in respondents with lower health literacy (57/100 versus 52/100, P=.03). Self-reported adherence to recommendations was high (85%) and increased with age and worry (both P<.001). Respondents rated their own adherence higher than others (85% versus 61%, P<.001). Moreover, 34% of respondents reported having self-quarantined; this rose to 52% for those aged ≥75 years. Those who had self-quarantined reported higher levels of fear. Nearly half (49%) of respondents felt the government response had been adequate, though younger age and higher levels of worry were associated with considering the response to be insufficient (both P<.001). Analysis of open-text answers revealed 4 major themes: access to and use of masks, gloves, and hand sanitizer; government messaging; lockdown and lockdown exit plan communication; and testing for COVID-19.

Conclusions

Knowledge, adherence, and satisfaction regarding government recommendations and response were high in this sample, but many desired greater access to personal protective equipment. Those with lower health literacy and those who have been in self-isolation reported greater concerns about the pandemic.

SOX10 is as specific as S100 protein in detecting metastases of melanoma in lymph nodes and is recommended for sentinel lymph node assessment

BACKGROUND

Sentinel lymph node (SLN) biopsy remains crucial for melanoma staging. The European Organisation for Research and Treatment of Cancer Melanoma Group recommends performing immunohistochemical stainings for reproducible identification of melanoma metastases. S100 protein (pS100) is a commonly used melanocytic antigen because of its high sensitivity in spite of relatively low specificity. SRY-related HMG-box 10 protein (SOX10) is a transcription factor characterising neural crest-derived cells. It is uniformly expressed mostly in the nuclei of melanocytes, neural, and myoepithelial cells. Pathologists sometimes prefer SOX10 as a melanoma marker, but it has not yet been investigated on a large-scale to confirm that it is reliable and recommendable for routine SLN evaluation.

METHODS

Four hundred one treatment-naïve lymph node (LN) metastatic melanomas were included in high-density tissue microarrays and were assessed for the presence of SOX10 and pS100 by immunohistochemistry. The slides were digitalised, shared and evaluated by a panel of experienced melanoma pathologists.

RESULTS

The vast majority of melanomas were double-positive for pS100 and SOX10 (93.2%); a small percentage of the cases (3.9%) were double-negative melanomas. Discordance between the two markers was observed: 1.9% pS100(-)/SOX10(+) and 0.75% pS100(+)/SOX10(-). SOX10 was not expressed by immune cell types in the LN, resulting in a less controversial interpretation of the staining.

CONCLUSIONS

SOX10 is as equally specific as pS100 for the detection of melanoma metastases in LNs. The interpretation of SOX10 staining is highly reproducible among different centres and different pathologists because of the absence of staining of immune cells.

Computerised scoring protocol for identification and quantification of different immune cell populations in breast tumour regions by the use of QuPath software

AIMS

As important prognostic and predictive information can be obtained from the composition, functionality and spatial arrangement of different immune cell subtypes, this study aims at characterizing the immune infiltrate in breast tumours.

METHODS AND RESULTS

Tumour-infiltrating lymphocytes (TILs) in 62 patients with luminal B-like breast cancer were characterised by immunohistochemical staining with standard markers, and were subsequently classified and quantified by the use of QuPath software. In different delineated tumour regions, the proportion and density of CD3⁺ , CD4⁺ , CD5⁺ , CD8⁺ , CD20⁺ and FOXP3⁺ cells were assessed. The results of the software analysis were compared with those of manual counting for CD8 and CD20 staining. The QuPath scoring protocol slightly overestimated positive, negative and total lymphocyte counts and density, while minimally underestimating the proportion of positively stained lymphocytes. However, for density and proportion, no real differences from manual counting were observed. For all markers, the density of positively stained immune cells was higher in the invasive front than in the tumour centre, pointing to an accumulation of immune cells near the tumour boundaries. When we looked at the proportion of immunohistochemically positive immune cells, we observed enrichment of CD5 (P = 0.025) and CD20 (P < 0.001) at the periphery, and FOXP3 enrichment in the centre (P < 0.001).

CONCLUSION

The QuPath scoring protocol can adequately identify positively stained immune cells in breast tumours, and allows the evaluation of differences in immune cell proportion and density within different tumour regions. The entire tumour section can be quantitatively assessed quite rapidly, which is a major advantage over manual counting.

Planning ahead with dementia: what role can advance care planning play? A review on opportunities and challenges

Advance directives emerged in the 1960s with the goal of empowering people to exert control over their future medical decisions. However, it has become apparent, over recent years, that advance directives do not sufficiently capture the temporal and relational aspects of planning treatment and care. Advance care planning (ACP) has been suggested as a way to emphasise communication between the patient, their surrogate decision maker and healthcare professional(s) in order to anticipate healthcare decisions in the event that the patient loses decision-making capacity, either temporarily or permanently. In more and more countries, ACP has become common practice in planning the treatment of terminal diseases such as cancer or amyotrophic lateral sclerosis. However, even though neurodegenerative dementia results in the gradual loss of decision-making capacity, ACP is still extremely rare. There are several reasons for this. Firstly, some people have difficulties talking about illness and death, especially when this involves anticipation. Secondly, lay people and professionals alike struggle to consider Alzheimer&rsquo;s disease and similar forms of dementia as terminal diseases. Thirdly, although patient decision-making capacity gradually decreases with the progression of dementia, the patient retains the ability to communicate and interact with surrogates and professionals until the later stages of the disease. Therefore, surrogates and professionals may feel unsure or even ambivalent when enforcing advance directives, in particular when those decisions may shorten a patient&rsquo;s life expectancy. Finally, to be effective, existing ACP interventions should be adapted to patient&rsquo;s cognitive impairments and lay out dementia-specific scenarios. Current WHO estimates indicate that by 2050 one out of four people will potentially have to take care of a relative with cognitive and communication impairments for several years. In Switzerland, the Federal Office of Public Health and the regional states have established national strategies on dementia and palliative care. These strategies emphasise the need for ACP as a means to prepare patients and their relatives for future decisions, as soon as someone is diagnosed with dementia. This moment is thus especially conducive to develop appropriate processes to prompt the elderly and people diagnosed with dementia to engage in ACP. Therefore, the aim of the present paper is to identify the benefits and challenges of ACP in dementia care, outline strategies to design appropriate procedures and tools, and provide professionals, patients and their relatives with opportunities to engage in ACP.

[Dementia from a palliative care perspective: why a disease-specific advance care planning is necessary]

Dementia from a palliative care perspective: why a disease-specific advance care planning is necessary Abstract. Palliative Care has to transform profoundly in the context of population aging in many countries around the globe. It has to collaborate increasingly with geriatric medicine and incorporate geriatric expertise. One of the pivotal challenges of geriatric palliative care is ethically appropriate decision making for patients who have lost decision-making capacity. While the traditional approach to advance directives (living wills) has demonstrably proven ineffective, the new approach that is currently being embraced, including in German-speaking countries, is the systemic process of advance care planning (ACP). In this article, ACP is first presented with its general aims, elements and effects. Second, it is shown why we need an adapted ACP program for people with dementia and what such a dementia-specific ACP must entail.

[Sarcoma centres : a necessary tool in the management of patients and for research.]

Sarcomas are rare diseases, the treatment of which requires an appropriate technical plateform and a broad spectrum of multidisciplinary specialists. Many are initially treated by unplanned excision, and then referred to specialized centres. Secondary treatments may lead to higher complication rates and local recurrence, with lower functional outcome, life quality and possibly overall survival. In order to improve the accessibility for referral to a specialist centre, the coordination of clinical and research activities, and the quality of the management of sarcomas in general, Lausanne University Hospital (CHUV) has opened a Sarcoma centre on October 1st 2016. The objective of the present paper is to illustrate the concept and provide useful clinical recommendations.

Is trauma in Switzerland any different? epidemiology and patterns of injury in major trauma - a 5-year review from a Swiss trauma centre

Switzerland, the country with the highest health expenditure per capita, is lacking data on trauma care and system planning. Recently, 12 trauma centres were designated to be reassessed through a future national trauma registry by 2015. Lausanne University Hospital launched the first Swiss trauma registry in 2008, which contains the largest database on trauma activity nationwide.

METHODS

Prospective analysis of data from consecutively admitted shock room patients from 1 January 2008 to 31 December 2012. Shock room admission is based on physiology and mechanism of injury, assessed by prehospital physicians. Management follows a surgeon-led multidisciplinary approach. Injuries are coded by Association for the Advancement of Automotive Medicine (AAAM) certified coders.

RESULTS

Over the 5 years, 1,599 trauma patients were admitted, predominantly males with a median age of 41.4 years and median injury severity score (ISS) of 13. Rate of ISS >15 was 42%. Principal mechanisms of injury were road traffic (40.4%) and falls (34.4%), with 91.5% blunt trauma. Principal patterns were brain (64.4%), chest (59.8%) and extremity/pelvic girdle (52.9%) injuries. Severe (abbreviated injury scale [AIS] score ≥ 3) orthopaedic injuries, defined as extremity and spine injuries together, accounted for 67.1%. Overall, 29.1% underwent immediate intervention, mainly by orthopaedics (27.3%), neurosurgeons (26.3 %) and visceral surgeons (13.9%); 43.8% underwent a surgical intervention within the first 24 hours and 59.1% during their hospitalisation. In-hospital mortality for patients with ISS >15 was 26.2%.

CONCLUSION

This is the first 5-year report on trauma in Switzerland. Trauma workload was similar to other European countries. Despite high levels of healthcare, mortality exceeds published rates by >50%. Regardless of the importance of a multidisciplinary approach, trauma remains a surgical disease and needs dedicated surgical resources.

Financial incentives to improve organ donation: what is the opinion of the Vaud French-speaking population?

BACKGROUND

With the increase of the organ shortage, several authors assume that financial incentives would improve organ donation rates and fill the unbalance between the demand and the organs available for transplant medicine. This line of argument has been criticised with people arguing that an exchange of money for organs would violate the legal and the ethical principle of gratuity, decrease voluntarism and increase the body parts commodification phenomena.

PURPOSE

Switzerland is often highlighted as having under-average organ donation rates compared to other European countries. In this paper we investigate the opinions of the Vaud French-speaking population concerning direct, indirect and non financial incentives in order to assess their opinions and anticipate the further debate.

METHODS

As part of a broad survey about the organ donation decision-making process, questions about incentives for both living and deceased organ donation were addressed to Vaud inhabitants and physicians.

RESULTS

The data collected showed that respondents were opposed to rewarding both living and deceased organ donation. The analysis of positive answers showed that indirect and non financial incentives were the most likely choice to acknowledge the donor's act. People in critical financial situations preferred direct financial incentives.

CONCLUSIONS

These results showed that altruism and gratuity were key-values in the organ donation and transplantation social perceptions of the respondents. Thus, we assume that introducing financial incentives could tarnish the image of transplant medicine. Nevertheless, further studies are needed to evaluate if their introduction would improve the organ donation rates or decrease voluntarism.

Visuospatial working memory deficits and visual pursuit impairments are not directly related in schizophrenia

OBJECTIVE

Patients with schizophrenia show deficits in visuospatial working memory and visual pursuit processes. It is currently unclear, however, whether both impairments are related to a common neuropathological origin. The purpose of the present study was therefore to examine the possible relations between the encoding and the discrimination of dynamic visuospatial stimuli in schizophrenia.

METHOD

Sixteen outpatients with schizophrenia and 16 control subjects were asked to encode complex disc displacements presented on a screen. After a delay, participants had to identify the previously presented disc trajectory from a choice of six static linear paths, among which were five incorrect paths. The precision of visual pursuit eye movements during the initial presentation of the dynamic stimulus was assessed. The fixations and scanning time in definite regions of the six paths presented during the discrimination phase were investigated.

RESULTS

In comparison with controls, patients showed poorer task performance, reduced pursuit accuracy during incorrect trials and less time scanning the correct stimulus or the incorrect paths approximating its global structure. Patients also spent less time scanning the leftmost portion of the correct path even when making a correct choice. The accuracy of visual pursuit and head movements, however, was not correlated with task performance.

CONCLUSIONS

The present study provides direct support for the hypothesis that active integration of visuospatial information within working memory is deficient in schizophrenia. In contrast, a general impairment of oculomotor mechanisms involved in smooth pursuit did not appear to be directly related to lower visuospatial working memory performance in schizophrenia.

Visuospatial encoding deficits and compensatory strategies in schizophrenia revealed by eye movement analysis during a working memory task

OBJECTIVE

To investigate scanpath abnormalities during the encoding of static stimuli in schizophrenia and their interaction with visuospatial working memory (VSWM) dysfunction.

METHODS

Outpatients with schizophrenia and control subjects were asked to encode a static pattern for subsequent recognition after a short delay. We measured the number of correct and incorrect choices. We also assessed the number and the distribution of fixations, the scanning time in specific regions of interest (ROIs) and the head movements during the encoding of the stimuli. The distributions of fixations and scanning time in definite ROIs during the discrimination of the correct pattern from the foils were also measured.

RESULTS

Patients recognised fewer correct patterns than controls. Correct trials in patients were characterised by a specific exploration of the central part of the stimulus during its presentation, whereas this feature was absent in incorrect trials. However, the scanning time and the numbers of fixations and head movements during encoding were similar in both groups and unrelated to recognition accuracy. In both groups, correct trials were associated with a selective exploration of the correct pattern amongst the six possibilities during recognition. Furthermore, patients gave more attention to incorrect patterns with a leftmost element identical to that of the correct response and also those approximating its global structure.

CONCLUSION

Patients showed a VSWM deficit independent of oculomotor dysfunctions and head movements during encoding. Patients' correct trials were related to specific scanning during encoding and discrimination phases. Analysis of these patterns suggests that patients try to compensate for reduced VSWM ability by using specific encoding strategies.