Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Br J Cancer ; 95(7): 801-10, 2006 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-17016484

RESUMO

Contrast enhanced magnetic resonance imaging (CE MRI) is the most sensitive tool for screening women who are at high familial risk of breast cancer. Our aim in this study was to assess the cost-effectiveness of X-ray mammography (XRM), CE MRI or both strategies combined. In total, 649 women were enrolled in the MARIBS study and screened with both CE MRI and mammography resulting in 1881 screens and 1-7 individual annual screening events. Women aged 35-49 years at high risk of breast cancer, either because they have a strong family history of breast cancer or are tested carriers of a BRCA1, BRCA2 or TP53 mutation or are at a 50% risk of having inherited such a mutation, were recruited from 22 centres and offered annual MRI and XRM for between 2 and 7 years. Information on the number and type of further investigations was collected and specifically calculated unit costs were used to calculate the incremental cost per cancer detected. The numbers of cancer detected was 13 for mammography, 27 for CE MRI and 33 for mammography and CE MRI combined. In the subgroup of BRCA1 (BRCA2) mutation carriers or of women having a first degree relative with a mutation in BRCA1 (BRCA2) corresponding numbers were 3 (6), 12 (7) and 12 (11), respectively. For all women, the incremental cost per cancer detected with CE MRI and mammography combined was pound28 284 compared to mammography. When only BRCA1 or the BRCA2 groups were considered, this cost would be reduced to pound11 731 (CE MRI vs mammography) and pound15 302 (CE MRI and mammography vs mammography). Results were most sensitive to the unit cost estimate for a CE MRI screening test. Contrast-enhanced MRI might be a cost-effective screening modality for women at high risk, particularly for the BRCA1 and BRCA2 subgroups. Further work is needed to assess the impact of screening on mortality and health-related quality of life.


Assuntos
Neoplasias da Mama/diagnóstico , Imageamento por Ressonância Magnética/economia , Mamografia/economia , Programas de Rastreamento/economia , Intensificação de Imagem Radiográfica/economia , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Análise Custo-Benefício , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Mutação , Fatores de Risco , Raios X
2.
Lancet ; 365(9473): 1769-78, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15910949

RESUMO

BACKGROUND: Women genetically predisposed to breast cancer often develop the disease at a young age when dense breast tissue reduces the sensitivity of X-ray mammography. Our aim was, therefore, to compare contrast enhanced magnetic resonance imaging (CE MRI) with mammography for screening. METHODS: We did a prospective multicentre cohort study in 649 women aged 35-49 years with a strong family history of breast cancer or a high probability of a BRCA1, BRCA2, or TP53 mutation. We recruited participants from 22 centres in the UK, and offered the women annual screening with CE MRI and mammography for 2-7 years. FINDINGS: We diagnosed 35 cancers in the 649 women screened with both mammography and CE MRI (1881 screens): 19 by CE MRI only, six by mammography only, and eight by both, with two interval cases. Sensitivity was significantly higher for CE MRI (77%, 95% CI 60-90) than for mammography (40%, 24-58; p=0.01), and was 94% (81-99) when both methods were used. Specificity was 93% (92-95) for mammography, 81% (80-83) for CE MRI (p<0.0001), and 77% (75-79) with both methods. The difference between CE MRI and mammography sensitivities was particularly pronounced in BRCA1 carriers (13 cancers; 92%vs 23%, p=0.004). INTERPRETATION: Our findings indicate that CE MRI is more sensitive than mammography for cancer detection. Specificity for both procedures was acceptable. Despite a high proportion of grade 3 cancers, tumours were small and few women were node positive. Annual screening, combining CE MRI and mammography, would detect most tumours in this risk group.


Assuntos
Neoplasias da Mama/diagnóstico , Predisposição Genética para Doença , Imageamento por Ressonância Magnética , Mamografia , Adulto , Neoplasias da Mama/genética , Carcinoma Intraductal não Infiltrante/diagnóstico , Carcinoma Intraductal não Infiltrante/genética , Estudos de Coortes , Meios de Contraste , Feminino , Gadolínio DTPA , Genes BRCA1 , Genes BRCA2 , Genes p53 , Humanos , Pessoa de Meia-Idade , Mutação , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade
3.
Clin Radiol ; 57(9): 807-14, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12384106

RESUMO

PURPOSE: To compare the histological grades of screen detected and non-screen detected ductal carcinoma in situ (DCIS) and to identify any differences that might support the contention that DCIS found by breast screening represents an over-diagnosis. The aim was also to establish whether any particular mammographic features of DCIS can be used to predict tumour grade reliably. MATERIALS AND METHODS: Biopsy proven cases of DCIS (n=153) were reviewed with respect to grade and subdivided into high, intermediate and low grades using the Van Nuys classification. A more aggressive subset of DCIS (microinvasive and interval cancers) were similarly analysed. Mammograms were reviewed with regard to abnormal features and distribution, and the appearances correlated with grade. RESULTS: Fifty-four percent (53/98) of screen detected and 62% (34/52) of non-screen detected DCIS were high grade. The rest were equally intermediate and low grade, with no statistical difference between the two groups. Eighty-four percent of the aggressive subset of tumours were high grade. Micro-calcification was present in 90% and in 10% there were soft tissue changes alone. Seventy-six percent of linear branching calcification was associated with high grade DCIS. Only 13% of high grade DCIS demonstrated punctate micro-calcification; however, 38% of cases of punctate micro-calfication were associated with high grade tumours and there was a great deal of overlap between the groups. CONCLUSION: Most cases of DCIS in both screen and non-screen detected groups were high grade. Only one in five was low grade. Analysis of the aggressive subgroup underlines the significance of high grade DCIS. Mammographic patterns are not always reliable in the prediction of tumour grade. The detection of DCIS in screening programmes is important and should not be regarded as over-diagnosis.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Programas de Rastreamento , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Mamárias/diagnóstico por imagem , Neoplasias da Mama/patologia , Calcinose/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Humanos , Mamografia , Pessoa de Meia-Idade , Invasividade Neoplásica
4.
J Exp Clin Cancer Res ; 21(3 Suppl): 107-14, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12585664

RESUMO

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.


Assuntos
Neoplasias da Mama/diagnóstico , Imageamento por Ressonância Magnética , Programas de Rastreamento , Adulto , Neoplasias da Mama/genética , Estudos de Coortes , Feminino , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Mamografia , Pessoa de Meia-Idade , Mutação , Seleção de Pacientes , Controle de Qualidade , Sensibilidade e Especificidade
5.
Br J Radiol ; 74(882): 548-51, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11459734

RESUMO

Breast lesions may be identified on MRI that are not shown on mammography or ultrasound owing to the high sensitivity and relatively poor specificity of contrast enhanced MRI. Techniques for diagnostic biopsy of such lesions are not widely available. A method is described that uses standard mammographic localization methods to place an MR compatible cerebral coil at the site of the suspect lesion. Confirmatory MRI can then be obtained before the lesion is surgically removed using a mammographic hook wire. This method is described and illustrated in detail for one case, and in summary for three further cases, to show the potential flexibility of application. The method is commended because it is simple and cheap, uses standard breast procedures and can be undertaken outside the MRI suite. The procedure will make full use of breast MRI possible to those who do not have dedicated localization equipment.


Assuntos
Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Adulto , Idoso , Biópsia/métodos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/diagnóstico por imagem , Carcinoma in Situ/diagnóstico , Carcinoma in Situ/diagnóstico por imagem , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Mamografia , Programas de Rastreamento , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia
6.
Am J Surg ; 181(2): 91-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11425066

RESUMO

BACKGROUND: This study aimed to examine the association between clinicopathologic parameters and positive margins in women with ductal carcinoma in situ (DCIS) treated by breast-conserving surgery (BCS). METHODS: We retrospectively reviewed the clinical, radiologic, and pathologic data of 100 women who had undergone BCS for DCIS in our center. RESULTS: Sixty-seven percent of patients presented via breast screening and 55% of all cases were diagnosed preoperatively on fine needle aspiration cytology ([FNAC] ie, C5). Overall, 45% of patients had clear margins after initial local excision. Positive margins showed a nonsignificant trend of association with distribution of microcalcifications (MCC), nonconsultant operating surgeon, inconclusive preoperative FNAC, presence of necrosis, and low specimen weight. There was a highly significant association between low grade DCIS (P = 0.003) and incomplete excision. There was no significant association with age, associated invasive focus, morphology of MCC, or with mode of presentation. CONCLUSION: Positive margins after local excision of DCIS are significantly associated with low nuclear grade, and preoperative determination of nuclear grade by core biopsy may have surgical implications.


Assuntos
Neoplasias da Mama/cirurgia , Mama/patologia , Carcinoma in Situ/cirurgia , Carcinoma Ductal de Mama/cirurgia , Biópsia por Agulha , Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Mastectomia Segmentar , Pessoa de Meia-Idade , Estudos Retrospectivos
7.
J Magn Reson Imaging ; 11(4): 343-50, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10767062

RESUMO

This study was undertaken to assess the utility of whole-body turbo short tau inversion recovery (STIR) magnetic resonance imaging (MRI) to detect metastases to liver, brain, and bone as a single examination in women with breast cancer. Seventeen patients with biopsy-proven breast cancer and suspected metastatic disease attending over a 12-month period referred for both conventional imaging and whole-body MRI were included in the study. Three patients were found to be free of metastases at both conventional and MR imaging. Appendicular or axial skeletal metastases were identified in 11 of 17 patients, with correlation between findings at whole-body MRI and scintigraphy in 15 of the 17 patients. Five patients had evidence of hepatic metastases on whole-body MRI, of which metastases were identified in only three patients at CT despite contrast enhancement. Four patients had brain abnormalities (metastases in three patients, meningioma in one patient) detected on both whole-body and dedicated brain MRI. Preliminary clinical experience suggests that turbo STIR whole-body MRI may represent a convenient and cost-effective method of total body screening for metastases in patients with breast carcinoma.


Assuntos
Neoplasias Ósseas/secundário , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Neoplasias Ósseas/diagnóstico , Neoplasias Encefálicas/diagnóstico , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Metástase Linfática , Imageamento por Ressonância Magnética/economia , Programas de Rastreamento/métodos , Meningioma/diagnóstico , Meningioma/secundário , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X , Contagem Corporal Total
8.
Eur Radiol ; 9(4): 693-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10354886

RESUMO

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade lymphoma that differs from high-grade non-Hodgkin lymphoma both clinically and histologically. The CT appearances of MALT lymphoma are described. Of 40 patients referred with biopsy-proven MALT lymphoma, only seven had not had gastrectomy or chemotherapy prior to CT examination. The CT scans of these seven cases were analysed for the degree and extent of gastric wall thickening, enlargement of abdominal and extra-abdominal lymph nodes, and presence of extra-nodal disease. In all patients the stomach was distended with oral contrast medium and scans performed at narrow collimation, after intravenous administration of 20 mg hyoscine butylbromide. In six patients focal thickening of the gastric wall was 1 cm or less. One patient had thickening of over 4 cm. There was no enlargement of abdominal or extra-abdominal lymph nodes or extension to adjacent organs. Thus on CT, at presentation, MALT lymphoma results in minimal gastric wall thickening, unlike high-grade non-Hodgkin lymphoma, which typically causes bulky gastric disease, nodal enlargement and extension into adjacent organs. CT is therefore of limited value in monitoring response to treatment. With disease greater than minimal thickening, transformation to a higher grade should be considered.


Assuntos
Linfoma de Zona Marginal Tipo Células B/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Biópsia , Brometo de Butilescopolamônio/administração & dosagem , Diagnóstico Diferencial , Feminino , Humanos , Injeções Intravenosas , Linfoma de Zona Marginal Tipo Células B/patologia , Masculino , Pessoa de Meia-Idade , Parassimpatolíticos/administração & dosagem , Neoplasias Gástricas/patologia
10.
Biochem J ; 216(2): 333-42, 1983 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-6661200

RESUMO

Administration of methoxamine (10 microM, 2 min) to perfused rat hearts increased the rate at which subsequently isolated mitochondria accumulated Ca2+. Methoxamine did not change significantly the development of delta phi with time or the basal rates of Ca2+ flux on inhibition of the uniporter with Ruthenium Red. With 200 microM-Pi, the rates of Ca2+ uptake at constant delta phi were unaffected by the small variations in endogenous [Pi] between mitochondrial preparations, and were also unaffected by changes in internal Ca2+ over the approximate range 8-43 nmol of Ca2+/mg. At low internal Ca2+ (about 8 nmol/mg of protein) the rates of Ca2+ uptake at constant delta phi were unaffected by addition of 200 microM-Pi. Under these conditions, the uniporter activity and the uniporter conductance were increased by 38-40% by methoxamine pretreatment. The endogenous Ca2+ content of mitochondria from control heart was about 1.8 nmol of Ca2+/mg of protein. Perfusion with agonist increased the Ca2+ content as follows: 10 microM-methoxamine (2 min), 48%; 1 microM-isoprenaline (2 min), 100%; 1 microM-adrenaline (2 min), 140%. The implications of the data for the adrenergic control of oxidative metabolism by intramitochondrial Ca2+ is discussed.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Metoxamina/farmacologia , Mitocôndrias Cardíacas/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Canais de Cálcio , Epinefrina/farmacologia , Feminino , Técnicas In Vitro , Isoproterenol/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Fosfatos/farmacologia , Ratos , Ratos Endogâmicos , Partículas Submitocôndricas/efeitos dos fármacos , Partículas Submitocôndricas/metabolismo
11.
Cell Calcium ; 4(4): 295-305, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6315241

RESUMO

Rat heart ventricular cells, purified by Percoll density gradient centrifugation, were incubated in the presence of 1.3 mM CaCl2. After 20 min incubation, samples of the cells were lysed in medium containing 0.3 mM digitonin, ruthenium red and EGTA, and a mitochondrial fraction was isolated at intervals thereafter. Extrapolation of the mitochondrial 45Ca2+ contents to zero time enabled the endogenous 45Ca2+ to be estimated at the time of cell lysis. The lysis conditions yielded essentially complete release of lactate dehydrogenase from the cells, but caused negligible damage to the mitochondria as judged by their retention of glutamate dehydrogenase, and their ability to accumulate and retain Ca2+ in the absence of ruthenium red and EGTA. The data indicate that about 13% of total cell Ca2+ only may be mitochondrial in vivo.


Assuntos
Cálcio/metabolismo , Mitocôndrias Cardíacas/metabolismo , Animais , Cátions Monovalentes/metabolismo , Fracionamento Celular , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Glutamato Desidrogenase/metabolismo , Ventrículos do Coração/metabolismo , L-Lactato Desidrogenase/metabolismo , Ratos , Ratos Endogâmicos
13.
Biochem J ; 200(2): 379-88, 1981 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-7340837

RESUMO

Mitochondria isolated from rat hearts perfused with adrenaline, and from hearts excised from adrenaline-treated rats, showed an enhanced rate of respiration-dependent Ca2+ uptake. Adrenaline pretreatment did not change the activity of the Na+/Ca2+-antiporter of isolated heart mitochondria. Simultaneous measurements of the membrane potential revealed that perfusion with adrenaline has no significant effect on this parameter during Ca2+ accumulation. The activation of Ca2+ uptake was induced also by the alpha-adrenergic agonist, methoxamine, but not by the beta-adrenergic agonist, isoprenaline. Methoxamine pretreatment also increased the sensitivity of alpha-oxoglutarate dehydrogenase in intact mitochondria to 10 nM--300 nM extramitochondrial Ca2+ during steady-state Ca2+ recycling across the inner membrane. Possible implications of these data for the adrenergic regulation of oxidative metabolism are discussed.


Assuntos
Cálcio/metabolismo , Epinefrina/farmacologia , Mitocôndrias Cardíacas/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Técnicas In Vitro , Isoproterenol/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Metoxamina/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Perfusão , Ratos , Ratos Endogâmicos , Sódio/metabolismo
14.
Biochem J ; 190(1): 119-23, 1980 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-6255939

RESUMO

1. Noradrenaline stimulates gluconeogenesis through an alpha-adrenoceptor in renal cortical tubule fragments from fed rats incubated with 5 mM-lactate. 2. The selective alpha 1-adrenoreceptor agonist methoxamine stimulated gluconeogenesis, but the selective alpha 2-adrenoceptor agonist clonidine was ineffective. 3. The selective alpha 1-adrenoceptor antagonist thymoxamine blocked the stimulatory effects on gluconeogenesis of noradrenaline and of oxymetazoline (a synthetic alpha-agonist). The selective alpha 2-adrenoceptor antagonist yohimbine was ineffective in this respect. 4. It is concluded that noradrenaline and oxymetazoline stimulate gluconeogenesis in rat kidney via an alpha 1-rather than an alpha 2-type of adrenoceptor.


Assuntos
Gluconeogênese/efeitos dos fármacos , Imidazóis/farmacologia , Córtex Renal/metabolismo , Norepinefrina/farmacologia , Oximetazolina/farmacologia , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos/metabolismo , Animais , Clonidina/farmacologia , Técnicas In Vitro , Córtex Renal/efeitos dos fármacos , Masculino , Metoxamina/farmacologia , Moxisilita/farmacologia , Ratos , Ioimbina/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA