Setting the international research agenda for sarcomas with patients and carers: results of phase II of the Sarcoma Patient Advocacy Global Network (SPAGN) priority setting partnership.

BACKGROUND: Typically, researchers and clinicians determine the agenda in sarcoma research. However, patient involvement can have a meaningful impact on research. Therefore, the Patient-Powered Research Network (PPRN) of the Sarcoma Patient Advocacy Global Network (SPAGN) set up a Priority Setting Partnership (PSP). The primary objective of this partnership is to identify priorities for research and patient advocacy topics. METHODS: In the first phase of this PSP, including 264 sarcoma patients and carers from all over the world, 23 research topics regarding sarcomas and 15 patient advocacy topics were identified using an online survey. In the second phase, participants were asked to fill in a top five and a top three of research and patient advocacy topics, respectively. Additionally, sociodemographic characteristics and sarcoma characteristics were collected. Social media channels, local national patient advocacy groups and the SPAGN website were used to distribute the survey. RESULTS: In total, 671 patients (75%) and carers (25%) participated in this survey. The five highest ranked research topics were related to causes of sarcoma (43%), prognosis and risk of recurrence (40%), specific subtypes of sarcoma (33%), the role of immunotherapy, targeted therapy and combined therapy (30%), and hereditary aspects (30%). The three highest ranked patient advocacy topics were improving the diagnostic process of sarcoma (39%), access to tumor DNA analysis (37%) and establishing an international sarcoma registry (37%). CONCLUSIONS: This sarcoma PSP has identified priorities for research and patient advocacy, offering guidance for researchers, assisting funding agencies with assessing project relevance and empowering patient advocates to represent the needs of patients and carers.

Expression of E-cadherin repressors SNAIL, ZEB1 and ZEB2 by tumour and stromal cells influences tumour-budding phenotype and suggests heterogeneity of stromal cells in pancreatic cancer.

BACKGROUND: There is evidence that tumour-stroma interactions have a major role in the neoplastic progression of pancreatic ductal adenocarcinoma (PDAC). Tumour budding is thought to reflect the process of epithelial-mesenchymal transition (EMT); however, the relationship between tumour buds and EMT remains unclear. Here we characterize the tumour-budding- and stromal cells in PDAC at protein and mRNA levels concerning factors involved in EMT. METHODS: mRNA in situ hybridisation and immunostaining for E-cadherin, ß-catenin, SNAIL1, ZEB1, ZEB2, N-cadherin and TWIST1 were assessed in the main tumour, tumour buds and tumour stroma on multipunch tissue microarrays from 120 well-characterised PDACs and associated with the clinicopathological features, including peritumoural (PTB) and intratumoural (ITB) budding. RESULTS: Tumour-budding cells showed increased levels of ZEB1 (P<0.0001) and ZEB2 (P=0.0119) and reduced E-cadherin and ß-catenin (P<0.0001, each) compared with the main tumour. Loss of membranous ß-catenin in the main tumour (P=0.0009) and tumour buds (P=0.0053), without nuclear translocation, as well as increased SNAIL1 in tumour and stromal cells (P=0.0002, each) correlated with high PTB. ZEB1 overexpression in the main tumour-budding and stromal cells was associated with high ITB (P=0.0084; 0.0250 and 0.0029, respectively) and high PTB (P=0.0005; 0.0392 and 0.0007, respectively). ZEB2 overexpression in stromal cells correlated with higher pT stage (P=0.03), lymphatic invasion (P=0.0172) and lymph node metastasis (P=0.0152). CONCLUSIONS: In the tumour microenvironment of phenotypically aggressive PDAC, tumour-budding cells express EMT hallmarks at protein and mRNA levels underlining their EMT-type character and are surrounded by stromal cells expressing high levels of the E-cadherin repressors ZEB1, ZEB2 and SNAIL1, this being strongly associated with the tumour-budding phenotype. Moreover, our findings suggest the existence of subtypes of stromal cells in PDAC with phenotypical and functional heterogeneity.

[Myositis as a post-acute sequela of COVID-19 disease? : Even in times of the pandemic, muscle biopsies can only be assessed in the context of accurate clinical information]. / Myositis als postakute Folge einer COVID-19-Erkrankung? : Auch in Zeiten der Pandemie können Muskelbiopsien oft nur im Kontext einer genauen Weitergabe klinischer Informationen beurteilt werden.

A case of a patient suffering from COVID-19 with suspected associated myositis is reported, in which the initially limited information about the history and disease course led to difficulties in establishing a reasonable diagnosis. Through inquiry, further data could be collected, so that the diagnosis of an infection-associated thrombotic microangiopathy in the context of a Morganella morganii myositis could be made. This patient study shows that even in times of the omnipresent pandemic and despite the context of a positive COVID-19 test result, differential diagnoses and the integrative clinicopathologic approach in interpreting muscle biopsy findings should not be neglected.

Setting the international research agenda for sarcoma together with patients and carers: first results of the Sarcoma Patient EuroNet (SPAEN) priority setting partnership.

BACKGROUND: Research in sarcomas has historically been the domain of scientists and clinicians attempting to understand the disease to develop effective treatments. This traditional approach of placing scientific rigor before the patient's reality is changing. This evolution is reflected in the growth of patient-centered organizations and patient advocacy groups that seek to meaningfully integrate patients into the research process. The aims of this study are to identify the unanswered questions regarding sarcomas (including gastrointestinal stromal tumors and desmoid fibromatosis) from patient, carer, and clinical perspectives and examine how patients and carers want to be involved in sarcoma research. METHODS: The Patient-Powered Research Network of Sarcoma Patients EuroNet set up a Priority Setting Partnership (PSP) in collaboration with stakeholders from the sarcoma research field. This PSP is largely based on the James Lind Alliance methodology. RESULTS: In total, 264 sarcoma patients (73%) and carers (27%) from all over the world participated in the online survey and covered the full spectrum of sarcomas. The topics mentioned were labeled in accordance with the Common Scientific Outline of the International Cancer Research Partnership and lists for potential research topics, advocacy topics, and requests for information were constructed. With regard to patient and carer involvement, 64% were very willing to be actively involved and mainly in the following areas: sharing perspectives, discussing patient-clinician interactions, and attending research meetings. CONCLUSIONS: The first results of this sarcoma PSP identified important research questions, but also important topics for patient advocacy groups and further improvement of information materials. Sarcoma patients and carers have a strong wish to be involved in multiple aspects of sarcoma research. The next phase will identify the top 10 research priorities per tumor type. These priorities will provide guidance for research that will achieve greatest value and impact.

[Treatment of retroperitoneal sarcoma in Germany : Results of a survey of the German Society of General and Visceral Surgery, the German Interdisciplinary Sarcoma Study Group and the advocacy group Das Lebenshaus]. / Behandlung retroperitonealer Sarkome in Deutschland : Eine Umfrage der Deutschen Gesellschaft für Allgemein- und Viszeralchirurgie, der Deutschen Interdisziplinären Studiengruppe Sarkome und der Patientenorganisation Das Lebenshaus.

OBJECTIVE: Retroperitoneal sarcomas (RPSs) are rare cancers with some variability in clinical and histopathological presentation. In Germany, general treatment strategies of retroperitoneal sarcoma are unknown since centralized registries do not exist. The objective of this survey was to access the medical care of RPS patients in Germany. METHODS: In cooperation with the German Society of General and Visceral surgery, the German Interdisciplinary Sarcoma Study Group and the patient advocacy group Das Lebenshaus we designed an online survey assessing diagnostic and treatment strategies (e. g. performance of tumor biopsies, administration of multimodal therapies and surgical strategy). All departments for general and visceral surgery in Germany were addressed (n = 976). RESULTS: Responses were received from 191 of 976 departments. Only 11 surgical departments treat more than 10 RPS patients per year. A multidisciplinary sarcoma board exists in 19 hospitals. Staging is generally performed by cross-sectional imaging. In 54% of the departments pretreatment tumor biopsy is a standard procedure. Surgery is performed as compartment resection in 85% of the departments. A systematic lymph node dissection is done in 40%. Adjuvant radio- or chemotherapy is performed as a standard treatment in 27% and 22% departments, respectively. CONCLUSION: The survey demonstrates a large heterogeneity in RPS diagnostic and treatment strategies. Dedicated education programs and centralized treatment strategies are warranted to improve the standard of care.

VEGF-ablation therapy reduces drug delivery and therapeutic response in ECM-dense tumors.

The inadequate transport of drugs into the tumor tissue caused by its abnormal vasculature is a major obstacle to the treatment of cancer. Anti-vascular endothelial growth factor (anti-VEGF) drugs can cause phenotypic alteration and maturation of the tumor's vasculature. However, whether this consistently improves delivery and subsequent response to therapy is still controversial. Clinical results indicate that not all patients benefit from antiangiogenic treatment, necessitating the development of criteria to predict the effect of these agents in individual tumors. We demonstrate that, in anti-VEGF-refractory murine tumors, vascular changes after VEGF ablation result in reduced delivery leading to therapeutic failure. In these tumors, the impaired response after anti-VEGF treatment is directly linked to strong deposition of fibrillar extracellular matrix (ECM) components and high expression of lysyl oxidases. The resulting condensed, highly crosslinked ECM impeded drug permeation, protecting tumor cells from exposure to small-molecule drugs. The reduced vascular density after anti-VEGF treatment further decreased delivery in these tumors, an effect not compensated by the improved vessel quality. Pharmacological inhibition of lysyl oxidases improved drug delivery in various tumor models and reversed the negative effect of VEGF ablation on drug delivery and therapeutic response in anti-VEGF-resistant tumors. In conclusion, the vascular changes after anti-VEGF therapy can have a context-dependent negative impact on overall therapeutic efficacy. A determining factor is the tumor ECM, which strongly influences the effect of anti-VEGF therapy. Our results reveal the prospect to revert a possible negative effect and to potentiate responsiveness to antiangiogenic therapy by concomitantly targeting ECM-modifying enzymes.

Embryonic stem cells: a novel tool for the study of antiangiogenesis and tumor-induced angiogenesis.

Major research initiatives in antiangiogenesis research have been undertaken to control angiogenic diseases such as polyarthritis, psoriasis, endometriosis, and diabetic retinopathy, and inhibition of tumor-induced angiogenesis has emerged as one of the most promising anti-cancer therapies currently available. Although several quantitative in vivo (i.e., animal models) as well as in vitro (i.e., pure endothelial cell cultures) angiogenesis assays have been described, the development of novel angiogenesis assays with organotypic culture systems that take into account oxygen and nutrient gradients, depth-dependent changes in intracellular pH and a redox state similar to that found in a natural tissue microenvironment are necessary to investigate blood vessel growth. Embryonic stem cells of mouse and human origin have the capacity to develop into three-dimensional tissues with functional capillaries, and this model system represents an excellent in vitro model for antiangiogenesis research. Upon confrontation of stem cells by co-culture with multicellular tumor spheroids, tumor-induced angiogenesis, i.e., the invasion of endothelial host-derived cells into a tumor tissue, can also be monitored. The current review provides an overview of embryonic stem cells as novel tools for antiangiogenesis research and outlines the use of confrontation cultures for the study of tumor-induced angiogenesis.

Similar clinical features in follicular lymphomas with and without breaks in the BCL2 locus.

Approximately 15% of follicular lymphomas (FLs) lack breaks in the BCL2 locus. The aim of this study was to better define molecular and clinical features of BCL2-breakpoint/t(14;18)-negative FLs. We studied the presence of BCL2, BCL6 and MYC breaks by fluorescence in situ hybridization and the expression of BCL2, MUM1, CD10, P53 and Ki67 in large clinical trial cohorts of 540 advanced-stage FL cases and 116 early-stage disease FL patients treated with chemotherapy regimens and radiation, respectively. A total of 86% and 53% of advanced- and early-stage FLs were BCL2-breakpoint-positive, respectively. BCL2 was expressed in almost all FLs with BCL2 break and also in 86% and 69% of BCL2-breakpoint-negative advanced- and early-stage FLs, respectively. CD10 expression was significantly reduced in BCL2-breakpoint-negative FLs of all stages and MUM1 and Ki67 expression were significantly increased in BCL2-break-negative early-stage FLs. Patient characteristics did not differ between FLs with and without BCL2 breaks and neither did survival times in advanced-stage FLs. These results suggest that the molecular profile differs to some extent between FLs with and without BCL2 breaks and support the notion that FLs with and without BCL2 breaks belong to the same lymphoma entity.

Activation of p90RSK and growth stimulation of multicellular tumor spheroids are dependent on reactive oxygen species generated after purinergic receptor stimulation by ATP.

Mitogenic stimulation by growth factors may be mediated through intracellular reactive oxygen species (ROS) acting as signaling molecules. Incubation of multicellular prostate tumor spheroids with adenosine 5' triphosphate (ATP) dose-dependently stimulated tumor growth. ATP, uridine 5'-triphosphate (UTP), adenosine 5'-diphosphate (ADP), and 2-methylthio-ATP (2-MeS-ATP) increased intracellular ROS levels significantly. ROS generation by ATP was inhibited by the P2 receptor antagonist suramin, by the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors diphenylene iodonium chloride (DPI) and 4-(2-aminoethyl) benzenesulfonylfluoride (AEBSF), as well as by the Ca2+-dependent phospholipase A2 (PLA2) inhibitors indomethacin and methyl arachidonyl fluorophosphonate (MAFP). The generation of ROS was dependent on the intracellular Ca2+ response evoked by ATP. Exogenous ATP activated the extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) pathway, which was blunted by the MAPK/ERK kinase 1/2 (MEK1/2) antagonist PD98059. The radical scavengers vitamin E, dimethyl thiourea (DMTU), and N-acetyl cysteine (NAC) failed to inhibit ERK1/2 activation but abolished p90 ribosomal S6 kinase (p90RSK) activation downstream of ERK1/2, as well as the growth stimulation of tumor spheroids. Our data indicate that p90RSK downstream of ERK1/2 is the molecular target for ROS generated through stimulation of purinergic receptors by ATP.

Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma.

Prognostically relevant risk factors in patients with diffuse large B-cell lymphoma (DLBCL) have predominantly been evaluated in elderly populations. We tested whether previously described risk factors are also valid in younger, poor-prognosis DLBCL patients. Paraffin-embedded samples from 112 patients with de novo DLBCL, enrolled in the R-MegaCHOEP trial of the German High Grade Non-Hodgkin Lymphoma Study Group (DSHNHL) were investigated using immunohistochemistry (MYC, FOXP1, LMO2, GCET1, CD5, CD10, BCL2, BCL6, IRF4/MUM1) and fluorescence in situ hybridization (MYC, BCL2, BCL6). MYC, BCL2 and BCL6 breaks occurred in 14, 21 and 31%, respectively. In the majority of cases, MYC was simultaneously rearranged with BCL2 and/or BCL6. The adverse impact of MYC rearrangements was confirmed, but the sole presence of BCL2 breaks emerged as a novel prognostic marker associated with inferior overall survival (OS) (P=0.002). Combined overexpression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin classifiers applied failed to predict survival time. DLBCL tumors with significant proportion of immunoblastic and/or immunoblastic-plasmacytoid cells had inferior OS, independently from from BCL2 break. Younger, poor-prognosis DLBCL patients, therefore, display different biological risk factors compared with an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker.

Redox-regulation of intrinsic prion expression in multicellular prostate tumor spheroids.

The cellular function of the intrinsic prion protein (PrPc) remains largely unknown. In the present study PrPc expression was investigated in multicellular prostate tumor spheroids and was correlated to the intracellular redox state as evaluated using the fluorescent dye 2'7'-dichlorodihydrofluorescein diacetate (H2DCFDA). In small tumor spheroids (diameter 100 +/- 20 microm) reactive oxygen species (ROS) levels were increased as compared with large (diameter 250 +/- 50 microm) spheroids. ROS generation was mediated by the mitochondrial respiratory chain and a NADPH oxidaselike enzyme, because carbonylcyanide-m-chlorophenylhydrazone (CCCP), rotenone, and diphenylene iodonium chloride (DPI) significantly reduced ROS levels. The elevated ROS were correlated to an increased expression of PrPc, Cu/Zn superoxide dismutase (SOD-1), and catalase in small as compared with large spheroids. In large tumor spheroids, PrPc was predominantly expressed in the peripheral cell layers and colocalized with SOD-1 and catalase. Raising intracellular ROS in large tumor spheroids by hydrogen peroxide, menadione, buthionine sulfoximine (BSO), and incubation in glutamine-reduced medium increased PrPc expression. In small spheroids PrPc was downregulated after incubation with the radical scavengers dehydroascorbate (DHA) and vitamin E. Our data indicate that PrPc expression in tumor spheroids is related to the intracellular redox state and may participate in antioxidative defense.

Role of reactive oxygen species and phosphatidylinositol 3-kinase in cardiomyocyte differentiation of embryonic stem cells.

Cardiotypic development in embryonic stem cell-derived embryoid bodies may be regulated by reactive oxygen species (ROS). ROS were generated by a NADPH oxidase-like enzyme which was transiently expressed during the time course of embryoid body development. Incubation with either H(2)O(2) or menadione enhanced cardiomyogenesis, whereas the radical scavengers trolox, pyrrolidinedithiocarbamate and N-acetylcysteine exerted inhibitory effects. The phosphatidylinositol 3-kinase (PI-3-kinase) inhibitors LY294002 and wortmannin abolished cardiac commitment and downregulated ROS in embryoid bodies. Coadministration of LY294002 with prooxidants resumed cardiomyocyte differentiation, indicating a role for PI-3-kinase in the regulation of the intracellular redox state.

Calcium-dependence of hydrogen peroxide-induced c-fos expression and growth stimulation of multicellular prostate tumor spheroids.

Hydrogen peroxide (H2O2) in nanomolar concentrations (20-100 nM) stimulated the growth of small (diameter 100 +/- 30 microm) multicellular prostate cancer spheroids and increased c-fos expression. H2O2 transiently raised [Ca2+]i by Ca2+ release from intracellular stores as the transient persisted in low (10 nM) Ca2+ solution but was abolished when intracellular Ca2+ stores were depleted by thapsigargin or chelation of [Ca2+]i with BAPTA. The H2O2-induced [Ca2+]i transient was furthermore inhibited by the P2-purinoreceptor antagonists suramin and basilen blue, indicating that H2O2 may act via purinergic receptor stimulation. Treatment of spheroids with either suramin, basilen blue or BAPTA inhibited the H2O2-induced growth stimulation and c-fos expression, indicating that the H2O2-mediated growth stimulation of multicellular spheroids is mediated via a Ca2+-dependent pathway.

Induction of cell death by Doxorubicin in multicellular spheroids as studied by confocal laser scanning microscopy.

In the present study the effects of the anticancer drug Doxorubicin (Dox) on necrosis development and cell lethality of multicellular DU-145 spheroids (MCS) were examined. Multicellular spheroids consist of a peripheral rim of proliferating cells, a inner shell of nonproliferating, quiescent cells and a central core of dead cells. After the application of Dox for different time periods dead cell areas and single dead cells in MCS of different size classes were identified using a set of lethal fluorescence dyes, and a confocal laser scanning microscope (CLSM). The distribution of Dox within MCS was examined by determining Dox fluorescence in single cells and cell areas. Outgrowth experiments were performed to show the effects of Dox on cancer cell migration and cell proliferation. The application of low (400 nM) concentrations of Dox over a time period of 2hours resulted in distinct Dox fluorescence staining of the most peripheral cell layers of the MCS. After long term incubation (48hours) cell lethality was most prominent in large spheroids (diameter between 350 and 800 micron) which possess a dead cell core and single dead cells at the periphery. These MCS showed an approximately 120 microm +/- 30 microm increased dead cell core as compared to control MCS. The cytotoxic effect of Dox was lower in MCS of a diameter between 150-350 microm and nearly no cytotoxic effects were found in spheroids smaller than 150 microm in diameter. Dox fluorescence persisted in dead cells for at least three days. During this time the cytotoxic agent leaked slowly from dead cells and penetrated into the layers of quiescent cells and proliferating cells mediating a prolonged cytotoxicity. In conclusion, the most efficient cytotoxic effect on MCS larger than 150 microm in diameter, can be achieved using a Dox concentration of 400 nM, and applying the drug for long incubation periods to allow its accumulation and storage in the dead cell core and in the single dead cells within vital cell layers. Dox is gradually delivered from these storage sites and kills proliferating and quiescent cells when no Dox is present in the external medium.

Implication of therapeutic cloning for organ transplantation.

Replacement of damaged myocardium with electrically functional, contracting syncytium with a balanced blood supply remains a key goal for the treatment of hearts damaged by coronary heart disease or other disorders. Stem cell therapy offers a potential solution. This paper describes the value of in vitro stem cell research to unravel the roles of key regulatory molecules in embryogenesis of myocardium and blood vessels. Studies have shown that functioning myocytes can be derived from stem cells in vitro and engrafted into infarcted areas of heart where they develop into functional adult like cardiomyocytes with action potentials and capacity for beta adrenergic and muscarinic regulation. Further studies have identified specific roles for platelet endothelial cell adhesion molecule (PECAM), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) in the sequential differentiation of blood vessels and capillaries.

Differentiating embryonic stem cells as an in vitro model of early erythropoiesis.

Extended studies on mouse embryos during the earliest stages of development are limited owing to both the large number of preimplantation embryos usually required and the difficulties in manipulating embryos after implantation; an in vitro model for embryogenesis would therefore be useful. Recently, blastocyst-derived mouse embryonic stem (ES) cells have been reported to differentiate in vitro to generate embryoid bodies (EBs) which form endoderm, mesoderm and ectoderm, thereby partially mimicking early stages of murine development. After 7 days of differentiation, EBs consisted of 6-10 x 10(3) cells. Confocal laser scanning microscopy of EBs after 13-14 days of differentiation (diameter 650-800 mum) revealed that they were vital, whereas similar-sized human malignant glioma (U 343 MG) cell spheroids showed cell death in the core region. To evaluate the potential of this system as an in vitro model of embryonic erythropoiesis, the EBs were analysed for the presence of erythropoietin (EPO) mRNA by reverse transcriptase-mediated polymerase chain reaction (RT-PCR) and we adapted a 2,7-diaminofluorene (DAF)-based staining method to detect haemoglobin in situ. DAF-positive cells appeared at day 5-6 of differentiation, whereas EPO mRNA was found in undifferentiated ES cells and in EBs at all stages of differentiation. Early expression of EPO mRNA prior to the onset of erythropoiesis implies that EPO may have a yet unknown role during early development. Apart from its potential to investigate embryonic erythropoiesis, this in vitro model may be useful for pharmacological and toxicological studies focused on early stages of development.

Quantitative recording of vitality patterns in living multicellular spheroids by confocal microscopy.

Fluorescent dyes were used in conjunction with confocal microscopy to record the vitality status of cells in multicellular glioma spheroids. Multicellular spheroids are in vitro models for micrometastases or intravascular microregions of large tumors. With progressing growth three distinct concentric annular shells develop. A rim of proliferating cells in the periphery is followed towards the center by layers of quiescent cells and at a defined spheroid diameter cell death occurs in the central core. Fluorescein diacetate (FDA) and Calcein/AM were used as vital stains and Lucifer Yellow/VS (LYVS) was used as a marker for dead cells. For loading multicellular spheroids with the esterase substrate dyes we used a two step cold incubation technique to avoid dye accumulation in the most peripheral cell layers. Homogenously stained tissue allowed to describe the fluorescence attenuation in depth as a monoexponential decay. An attenuation coefficient C was calculated from calibration experiments to be 12.5 x 10(-3) in vital stained tissue and 17.9 x 10(-3) in lethal stained tissue. Using the respective attenuation coefficient the raw data were corrected for light absorption and scattering in depth. In radial recordings of the vitality status of multicellular glioma spheroids using CLSM-technique we showed that spheroids up to a diameter of 250 microns were homogenously stained with Calcein/AM and FDA. Spheroids larger than 250 microns consist of vital stained cells and unstained cells. They do not show dead cell staining until they reach a diameter of about 400 microns. The thickness of the rim of vital stained cells decreased with increasing diameter of the spheroids to 64 +/- 7 microns in spheroids of a diameter of 550 +/- 25 microns. Thereafter the thickness of the Calcein/AM or FDA stained rim augmented again, reaching 93 +/- 9 microns in spheroids of 700 microns in diameter. The first signs of dead cell staining in the central core occurred at a diameter of 400 +/- 25 microns. The radius of the core increased in an exponential way. The cell layer which was stained neither by vital nor by lethal dyes showed a thickness of 150 microns in spheroids of 550 +/- 25 microns in diameter. Our staining technique and the radial recording of mean field fluorescence signals in living multicellular spheroids will be a valuable tool for experimental cancer research providing a non invasive quantification of cell vitality in living multicellular spheroids.

Spontaneous liver rupture after treatment with drug-eluting beads.

Spontaneous rupture of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is a rare and life-threatening complication. Pathophysiologic mechanisms are not yet fully known; it is suggested that rupture is preceded by reactive tissue edema and intratumerous bleeding, leading to a rapid expansion of tumour mass with risk of extrahepatic bleeding in the case of subcapsular localisation. This case report discusses a sudden, unexpected lethal complication in a 74 year-old male patient treated with TACE using DC Bead loaded with doxorubicin (DEBDOX) in a progressive multifocal HCC.