Search results for "sarcoma"
showing 10 items of 566 documents
Cytogenetic and molecular findings related to rhabdomyosarcoma. An analysis of seven cases.
2003
Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood. Histologically, it is subdivided histologically into two main subtypes: alveolar (ARMS) and embryonal (ERMS). ARMS is characterized by t(2;13)(q35;q14) or its variant t(1;13)(p36;q14), which fuse PAX3 and PAX7, respectively, with FKHR to produce chimeric genes. ERMS is frequently associated with loss of heterozygosity of 11p15.5. We investigated seven RMS (three ARMS and four ERMS) by means of cytogenetic, fluorescence in situ hybridization, and molecular analyses, including the study of the main genes implicated in the G1- to S-phase cell cycle transition, and correlated these studies with pathologic findings and c…
pH distributions in spontaneous and isotransplanted rat tumours.
1988
Spontaneous mammary tumours of the rat with various degrees of malignancy exhibit similar tissue pH distributions. The mean pH (+/- s.d.) of dysplasia is 7.05 +/- 0.20. In benign tumours the mean pH is 6.95 +/- 0.19 and in malignant tumours it is 6.94 +/- 0.19. In contrast, tumours with the same degree of malignancy but different histologies show different pH distributions. Benign tumours with a higher percentage of fibrous tissue exhibit less acidic pH values than those with larger portions of epithelial cells (delta pH = 0.38 pH units). The pH distribution in the benign tumours is independent of the tumour wet weight up to stages of very advanced growth. In the malignant tumours, a trend …
Quantitative changes of metabolic and bioenergetic parameters in experimental tumors during fractionated irradiation.
1999
Abstract Purpose: Previous studies with rat rhabdomyosarcomas indicate that during fractionated irradiation profound alterations of the tumor microvasculature and the oxygenation status occur when the total dose exceeds 45 Gy. At this dose a destruction which included all structures of the vessels and a significant worsening in tumor oxygenation were found. The aim of the present study was to analyze whether these effects of fractionated irradiation on the microvasculature and on tumor oxygenation also induce changes in the bioenergetic and metabolic status in the tumors during radiation treatment. Methods and Materials: R1H rhabdomyosarcomas of the rat implanted into the flank were irradia…
Incidence and time trends of soft tissue sarcomas in German children 1985-2004 - a report from the population-based German Childhood Cancer Registry.
2008
Abstract The incidence of soft tissue sarcoma (STS) in Europe is increasing, but it is unclear whether this increase can also be seen in Germany. We analysed the heterogeneous group of STS recorded to the German Childhood Cancer Registry (GCCR) between 1985 and 2004 with respect to incidence data. Age-specific, age-standardised and cumulative incidence rates were calculated. Additionally, the average annual percent change (AAPC), derived from a Poisson regression model, was estimated, using time in years as the explanatory, continuous variable. Two thousand sixty-one children were diagnosed at a median age of 72 months. Most common are rhabdomyosarcomas (RMS) (n = 1202) and fibrosarcomas (n…
Expression of insulin-like growth factor system components in Ewing's sarcoma and their association with survival.
2010
Abstract Aims The role of IGF system in the pathogenesis of Ewing’s sarcoma (EWS) is well-documented. However, still little information is available about the value of IGF system components as indicators of prognosis. Understanding the clinical role for IGF system in EWS patients may be important because different subtypes of patients have distinct outcome and may require different treatment protocol. We evaluated the expression of insulin-like growth factor (IGF)-receptor (IGF-IR), insulin receptor (IR), IGF-I and some major intracellular mediators (IRS1, p-ERK) in specimens from EWS patients with primary localised untreated tumours. Patients and methods 290 samples were used for immunohis…
Enhanced radiosensitivity in experimental tumours following erythropoietin treatment of chemotherapy-induced anaemia.
1998
The radiosensitivity of solid tumours in anaemic rats treated with recombinant human erythropoietin (rhEPO, epoetin beta) was studied. Anaemia was induced by a single dose of carboplatin (45 mg kg(-1) i.v.), resulting in a reduction in the haemoglobin concentration by 30%. In a second group, the development of anaemia was prevented by rhEPO (1000 IU kg(-1)) administered s.c. three times per week starting 6 days before the carboplatin application. Three days after carboplatin treatment, DS-sarcomas were implanted subcutaneously onto the hind foot dorsum. Neither carboplatin nor rhEPO treatment influenced tumour growth rate. Five days after implantation, tumours were irradiated with a single …
Postoperative Radiation Therapy in Patients with Extracranial Chondrosarcoma: A Joint Study of the French Sarcoma Group and Rare Cancer Network
2020
International audience; PurposePostoperative radiation therapy (poRT) of intracranial/skull base chondrosarcomas (CHSs) is standard treatment. However, consensus is lacking for poRT in extracranial CHS (eCHS) owing to their easier resectability and intrinsic radioresistance. We assessed the practice and efficacy of poRT in eCHS.Methods and MaterialsThis multicentric retrospective study of the French Sarcoma Group/Rare Cancer Network included patients with eCHS who were operated on between 1985 and 2015. Inverse propensity score weighting (IPTW) was used to minimize poRT allocation biases.ResultsOf 182 patients, 60.4% had bone and 39.6% had soft-tissue eCHS. eCHS were of conventional (31.9%)…
l-glutamine: a major substrate for tumor cells in vivo?
1987
From 65 human breast cancer xenografts investigated, a net glutamine uptake was found in 13 tumors (mean +/- SE: 15.7 +/- 4.5 nmol/g per min) whereas a net release (22.5 +/- 3.3 nmol/g per min) was observed in 40 tumors. In 12 tumors neither a significant net uptake nor a net release was obvious. There is experimental evidence that glutamine is taken up by cancer cells only at arterial concentrations greater than 0.5 mM. Another parameter determining glutamine utilization by tumor cells may be the tissue oxygenation. In hypoxic or anoxic tumor areas, glutamine oxidation is unlikely since oxygen is required for the reoxidation of coenzymes which are reduced in the course of this metabolic pa…
Blood flow, oxygenation, metabolic and energetic status in different clonal subpopulations of a rat rhabdomyosarcoma.
1998
Differentiation of a tumor plays an important role in terms of biological aggressiveness. The question arises as to whether this is reflected in differences in the metabolic and energetic status of solid tumors. The aim of this study was to analyze the influence of clonal tumor cell differentiation on the microenvironment of rat rhabdomyosarcomas. Two distinct lines of a rhabdomyosarcoma (BA-HAN-1) with different histomorphological properties were used (line F1, co-existence of mononuclear stellate cells and multinuclear myotube-like giant tumor cells; G8, polygonal, mononuclear tumor cells). Solid tumors were grown s.c. on the hind food dorsum of Lewis rats. Tumor oxygenation was measured …
Localized hypothermia: impact on oxygenation, microregional perfusion, metabolic and bioenergetic status of subcutaneous rat tumours.
1998
The effect of localized hypothermia on microcirculatory and metabolic parameters in s.c. DS sarcomas on the hind foot dorsum of Sprague-Dawley rats was investigated. Tumours were cooled by superfusion of the tumour surface with cooled saline solution to 25 degrees C or 15 degrees C. Control tumours remained at 35 degrees C. These temperatures were maintained for 30 min. In tumour oxygenation measurements, hypothermia at 25 degrees C and 15 degrees C caused progressive decreases in the size of the fraction of pO2 measurements between 0 and 2.5 mmHg together with a reduction in pO2 variability. No significant changes in median or mean pO2 or in the fraction of pO2 measurements between 0 and 5…