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1.
Eur J Cancer ; 47(17): 2517-30, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21741831

RESUMO

BACKGROUND: The risk of recurrence following surgery in women with early breast cancer varies, depending upon prognostic factors. Adjuvant chemotherapy reduces this risk; however, increasingly effective regimens are associated with higher costs and toxicity profiles, making it likely that different regimens may be cost-effective for women with differing prognoses. To investigate this we performed a cost-effectiveness analysis of four treatment strategies: (1) no chemotherapy, (2) chemotherapy using cyclophosphamide, methotrexate, and fluorouracil (CMF) (a first generation regimen), (3) chemotherapy using Epirubicin-CMF (E-CMF) or fluorouracil, epirubicin, and cyclophosphamide (FEC60) (a second generation regimens), and (4) chemotherapy with FEC60 followed by docetaxel (FEC-D) (a third generation regimen). These adjuvant chemotherapy regimens were used in three large UK-led randomised controlled trials (RCTs). METHODS: A Markov model was used to simulate the natural progression of early breast cancer and the impact of chemotherapy on modifying this process. The probability of a first recurrent event within the model was estimated for women with different prognostic risk profiles using a parametric regression-based survival model incorporating established prognostic factors. Other probabilities, treatment effects, costs and quality of life weights were estimated primarily using data from the three UK-led RCTs, a meta-analysis of all relevant RCTs, and other published literature. The model predicted the lifetime costs, quality adjusted life years (QALYs) and cost-effectiveness of the four strategies for women with differing prognoses. Sensitivity analyses investigated the impact of uncertain parameters and model assumptions. FINDINGS: For women with an average to high risk of recurrence (based upon prognostic factors and any other adjuvant therapies received), FEC-D appeared most cost-effective assuming a threshold of £20,000 per QALY for the National Health Service (NHS). For younger low risk women, E-CMF/FEC60 tended to be the optimal strategy and, for some older low risk women, the model suggested a policy of no chemotherapy was cost-effective. For no patient group was CMF chemotherapy the preferred option. Sensitivity analyses demonstrated cost-effectiveness results to be particularly sensitive to the treatment effect estimate for FEC-D and the future price of docetaxel. INTERPRETATION: To our knowledge, this analysis is the first cost-effectiveness comparison of no chemotherapy, and first, second, and third generation adjuvant chemotherapy regimens for early breast cancer patients with differing prognoses. The results demonstrate the potential for different treatment strategies to be cost-effective for different types of patients. These findings may prove useful for policy makers attempting to formulate cost-effective treatment guidelines in the field of early breast cancer.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/economia , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/economia , Quimioterapia Adjuvante/economia , Análise Custo-Benefício , Ciclofosfamida/economia , Ciclofosfamida/uso terapêutico , Docetaxel , Epirubicina/economia , Epirubicina/uso terapêutico , Feminino , Fluoruracila/economia , Fluoruracila/uso terapêutico , Custos de Cuidados de Saúde , Humanos , Metotrexato/economia , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Prognóstico , Anos de Vida Ajustados por Qualidade de Vida , Taxoides/economia , Taxoides/uso terapêutico
2.
Br J Pharmacol ; 154(7): 1465-73, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18536749

RESUMO

BACKGROUND AND PURPOSE: Inhibition of cholesteryl ester transfer protein (CETP) with torcetrapib in humans increases plasma high density lipoprotein (HDL) cholesterol levels but is associated with increased blood pressure. In a phase 3 clinical study, evaluating the effects of torcetrapib in atherosclerosis, there was an excess of deaths and adverse cardiovascular events in patients taking torcetrapib. The studies reported herein sought to evaluate off-target effects of torcetrapib. EXPERIMENTAL APPROACH: Cardiovascular effects of the CETP inhibitors torcetrapib and anacetrapib were evaluated in animal models. KEY RESULTS: Torcetrapib evoked an acute increase in blood pressure in all species evaluated whereas no increase was observed with anacetrapib. The pressor effect of torcetrapib was not diminished in the presence of adrenoceptor, angiotensin II or endothelin receptor antagonists. Torcetrapib did not have a contractile effect on vascular smooth muscle suggesting its effects in vivo are via the release of a secondary mediator. Treatment with torcetrapib was associated with an increase in plasma levels of aldosterone and corticosterone and, in vitro, was shown to release aldosterone from adrenocortical cells. Increased adrenal steroid levels were not observed with anacetrapib. Inhibition of adrenal steroid synthesis did not inhibit the pressor response to torcetrapib whereas adrenalectomy prevented the ability of torcetrapib to increase blood pressure in rats. CONCLUSIONS AND IMPLICATIONS: Torcetrapib evoked an acute increase in blood pressure and an acute increase in plasma adrenal steroids. The acute pressor response to torcetrapib was not mediated by adrenal steroids but was dependent on intact adrenal glands.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Oxazolidinonas/toxicidade , Quinolinas/toxicidade , Córtex Suprarrenal/citologia , Córtex Suprarrenal/efeitos dos fármacos , Aldosterona/sangue , Animais , Anticolesterolemiantes/toxicidade , Corticosterona/sangue , Cães , Avaliação Pré-Clínica de Medicamentos , Feminino , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie
3.
J Am Coll Cardiol ; 36(7): 2247-53, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11127468

RESUMO

OBJECTIVES: The goal of this study was to compare T-wave alternans (TWA), signal-averaged electrocardiography (SAECG) and programmed ventricular stimulation (EPS) for arrhythmia risk stratification in patients undergoing electrophysiology study. BACKGROUND: Accurate identification of patients at increased risk for sustained ventricular arrhythmias is critical to prevent sudden cardiac death. T-wave alternans is a heart rate dependent measure of repolarization that correlates with arrhythmia vulnerability in animal and human studies. Signal-averaged electrocardiography and EPS are more established tests used for risk stratification. METHODS: This was a prospective, multicenter trial of 313 patients in sinus rhythm who were undergoing electrophysiologic study. T-wave alternans, assessed with bicycle ergometry, and SAECG were measured before EPS. The primary end point was sudden cardiac death, sustained ventricular tachycardia, ventricular fibrillation or appropriate implantable defibrillator (ICD) therapy, and the secondary end point was any of these arrhythmias or all-cause mortality. RESULTS: Kaplan-Meier survival analysis of the primary end point showed that TWA predicted events with a relative risk of 10.9, EPS had a relative risk of 7.1 and SAECG had a relative risk of 4.5. The relative risks for the secondary end point were 13.9, 4.7 and 3.3, respectively (p < 0.05). Multivariate analysis of 11 clinical parameters identified only TWA and EPS as independent predictors of events. In the prespecified subgroup with known or suspected ventricular arrhythmias, TWA predicted primary end points with a relative risk of 6.1 and secondary end points with a relative risk of 8.0. CONCLUSIONS: T-wave alternans is a strong independent predictor of spontaneous ventricular arrhythmias or death. It performed as well as programmed stimulation and better than SAECG in risk stratifying patients for life-threatening arrhythmias.


Assuntos
Arritmias Cardíacas/diagnóstico , Eletrocardiografia/métodos , Técnicas Eletrofisiológicas Cardíacas , Idoso , Arritmias Cardíacas/mortalidade , Arritmias Cardíacas/fisiopatologia , Morte Súbita Cardíaca , Teste de Esforço , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador , Análise de Sobrevida , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia
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