1,260 research outputs found

    Factors Influencing Prognosis After Initial Inadequate Excision (IIE) for Soft Tissue Sarcoma

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    Purpose. The influence of initial inadequate excision (IIE) of soft tissue sarcoma (STS) on local control and overall survival is not well established. It is generally believed that an IIE may have a negative impact on both, despite subsequent treatment by radical surgery and radiotherapy. However, data on local recurrence-free survival/overall survival are conflicting and there are no data on the effect of IIE on overall survival

    Equilibria of biological aggregations with nonlocal repulsive-attractive interactions

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    We consider the aggregation equation ρt(ρKρ)=0\rho_{t}-\nabla\cdot(\rho\nabla K\ast\rho) =0 in Rn\mathbb{R}^{n}, where the interaction potential KK incorporates short-range Newtonian repulsion and long-range power-law attraction. We study the global well-posedness of solutions and investigate analytically and numerically the equilibrium solutions. We show that there exist unique equilibria supported on a ball of Rn\mathbb{R}^n. By using the method of moving planes we prove that such equilibria are radially symmetric and monotone in the radial coordinate. We perform asymptotic studies for the limiting cases when the exponent of the power-law attraction approaches infinity and a Newtonian singularity, respectively. Numerical simulations suggest that equilibria studied here are global attractors for the dynamics of the aggregation model

    Cancer Core Europe: A translational research infrastructure for a European mission on cancer

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    Alliance; Cancer research; InfrastructureAliança; Recerca oncològica; InfraestructuraAlianza; Investigación oncológica; InfraestructuraCancer Core Europe is a European legal alliance consisting of seven leading cancer centres - most of them Comprehensive Cancer Centres (CCCs) - with a single portal system to engage in various research projects with partners. Cancer Core Europe was established to create a sustainable, high-level, shared research infrastructure platform hosting research collaborations and task forces (data sharing, clinical trials, genomics, immunotherapy, imaging, education and training, and legal and ethical issues), with a controlled expansion agenda. Translational cancer research covers the cancer research continuum from basic to preclinical to early clinical, late clinical, and outcomes research. Basic-preclinical research serves as the 'engine' for early clinical research by bridging the early translational research gap and is the primary and current focus of the consortium as exemplified by the launching of the Basket of Baskets trial, Europe's largest precision cancer medicine trial. Inspired by the creation of Cancer Core Europe, the prevention community established Cancer Prevention Europe, a consortium of ten cancer prevention centres aimed at supporting the complete prevention research continuum. Presently, Cancer Core Europe and Cancer Prevention Europe are integrating therapeutics and prevention strategies to address in partnership the widening cancer problem. By providing innovative approaches for cancer research, links to healthcare systems, development of quality-assured multidisciplinary cancer care, and assessment of long-term outcomes, the virtual infrastructure will serve as a hub to connect and interact with other centres across Europe and beyond. Together, Cancer Core Europe and Cancer Prevention Europe are prepared to function as a central engine to tackle, in collaboration with various partners, a potential 'mission on cancer' addressing the cancer burden

    Investigation of Factors Determining the Enhanced Permeability and Retention Effect in Subcutaneous Xenografts

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    Liposomal chemotherapy offers several advantages over conventional therapies, including high intratumoral drug delivery, reduced side effects, prolonged circulation time and the possibility to dose higher. The efficient delivery of liposomal chemotherapeutics relies however on the enhanced permeability and retention (EPR) effect, which refers to the ability of macromolecules to extravasate leaky tumor vessels and accumulate in the tumor tissue. Using a panel of human xenograft tumors, we evaluated the influence of the EPR effect on liposomal distribution in vivo by injection of pegylated liposomes radiolabeled with 111In. Liposomal accumulation in tumors and organs was followed over time by SPECT/CT imaging. We observed that fast growing xenografts, which may be less representative of tumor development in patients, showed higher liposomal accumulation as compared to slow growing xenografts. Additionally, several other parameters determining the EPR effect were evaluated, such as blood and lymphatic vessel density, intratumoral hypoxia, and the presence of macrophages. The investigation of various parameters showed a few correlations. Although hypoxia, proliferation and macrophage presence were associated with tumor growth, no hard conclusions or predictions could be made regarding the EPR effect or liposomal uptake. However liposomal uptake was

    Synergistic effects of TNF-alpha and melphalan in an isolated limb perfusion model of rat sarcoma: a histopathological, immunohistochemical and electron microscopical study.

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    Isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan has shown impressive results in patients with irresectable soft tissue sarcomas and stage III melanoma of the extremities. The mechanisms of the reported in vivo synergistic anti-tumour effects of TNF-alpha and melphalan are not precisely understood. We have developed an ILP model in the rat using a non-immunogenic sarcoma in which similar in vivo synergy is observed. The aim of this present study was to analyse the morphological substrate for this synergistic response of TNF-alpha in combination with melphalan to shed more light on the pathomechanisms involved. Histology of the tumours from saline- (n = 14) and melphalan-treated (n = 11) rats revealed apparently vital tumour cells in over 80% of the cross-sections. Interstitial oedema and coagulation necrosis were observed in the remaining part of the tumour. Haemorrhage was virtually absent. TNF-alpha (n = 22) induced marked oedema, hyperaemia, vascular congestion, extravasation of erythrocytes and haemorrhagic necrosis (20-60% of the cross-sections). Oedema and haemorrhage suggested drastic alterations of permeability and integrity of the microvasculature. Using light and electron-microscopy, we observed that haemorrhage preceded generalised platelet aggregation. Therefore, we suggest that the observed platelet aggregation was the result of the microvascular damage rather than its initiator. Remarkably, these events hardly influenced tumour growth. However, perfusion with the combination of TNF-alpha and melphalan (n = 24) showed more extensive haemorrhagic necrosis (80-90% of the cross-sections) and revealed a prolonged remission (mean 11 days) in comparison with the other groups of rats. Electron microscopical analysis revealed similar findings as described after TNF-alpha alone, although the effects were more prominent at all time points after perfusion. In conclusion, our findings suggest that the enhanced anti-tumour effect after the combination of TNF-alpha with melphalan results from potentiation of the TNF-alpha-induced vascular changes accompanied by increased vascular permeability and platelet aggregation. This may result in additive cytotoxicity or inhibition of growth of residual tumour cells

    Small molecules and targeted therapies in distant metastatic disease

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    Chemotherapy, biological agents or combinations of both have had little impact on survival of patients with metastatic melanoma. Advances in understanding the genetic changes associated with the development of melanoma resulted in availability of promising new agents that inhibit specific proteins up-regulated in signal cell pathways or inhibit anti-apoptotic proteins. Sorafenib, a multikinase inhibitor of the RAF/RAS/MEK pathway, elesclomol (STA-4783) and oblimersen (G3139), an antisense oligonucleotide targeting anti-apoptotic BCl-2, are in phase III clinical studies in combination with chemotherapy. Agents targeting mutant B-Raf (RAF265 and PLX4032), MEK (PD0325901, AZD6244), heat-shock protein 90 (tanespimycin), mTOR (everolimus, deforolimus, temsirolimus) and VEGFR (axitinib) showed some promise in earlier stages of clinical development. Receptor tyrosine-kinase inhibitors (imatinib, dasatinib, sunitinib) may have a role in treatment of patients with melanoma harbouring c-Kit mutations. Although often studied as single agents with disappointing results, new targeted drugs should be more thoroughly evaluated in combination therapies. The future of rational use of new targeted agents also depends on successful application of analytical techniques enabling molecular profiling of patients and leading to selection of likely therapy responder

    Tumour necrosis factor alpha increases melphalan concentration in tumour tissue after isolated limb perfusion

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    Several possible mechanisms for the synergistic anti-tumour effects between tumour necrosis factor alpha (TNF-α) and melphalan after isolated limb perfusion (ILP) have been presented. We found a significant sixfold increase in melphalan tumour tissue concentration after ILP when TNF-α was added to the perfusate, which provides a straightforward explanation for the observed synergism between melphalan and TNF-α in ILP. © 2000 Cancer Research Campaig
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