944 resultados para Perinatal androgen blockade


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BACKGROUND: Few randomised studies have compared antiandrogen intermittent hormonal therapy (IHT) with continuous maximal androgen blockade (MAB) therapy for advanced prostate cancer (PCa). OBJECTIVE: To determine whether overall survival (OS) on IHT (cyproterone acetate; CPA) is noninferior to OS on continuous MAB. DESIGN, SETTING, AND PARTICIPANTS: This phase 3 randomised trial compared IHT and continuous MAB in patients with locally advanced or metastatic PCa. INTERVENTION: During induction, patients received CPA 200 mg/d for 2 wk and then monthly depot injections of a luteinising hormone-releasing hormone (LHRH; triptoreline 11.25 mg) analogue plus CPA 200 mg/d. Patients whose prostate-specific antigen (PSA) was <4 ng/ml after 3 mo of induction treatment were randomised to the IHT arm (stopped treatment and restarted on CPA 300 mg/d monotherapy if PSA rose to ≥20 ng/ml or they were symptomatic) or the continuous arm (CPA 200 mg/d plus monthly LHRH analogue). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary outcome measurement was OS. Secondary outcomes included cause-specific survival, time to subjective or objective progression, and quality of life. Time off therapy in the intermittent arm was recorded. RESULTS AND LIMITATIONS: We recruited 1045 patients, of which 918 responded to induction therapy and were randomised (462 to IHT and 456 to continuous MAB). OS was similar between groups (p=0.25), and noninferiority of IHT was demonstrated (hazard ratio [HR]: 0.90; 95% confidence interval [CI], 0.76-1.07). There was a trend for an interaction between PSA and treatment (p=0.05), favouring IHT over continuous therapy in patients with PSA ≤1 ng/ml (HR: 0.79; 95% CI, 0.61-1.02). Men treated with IHT reported better sexual function. Among the 462 patients on IHT, 50% and 28% of patients were off therapy for ≥2.5 yr or >5 yr, respectively, after randomisation. The main limitation is that the length of time for the trial to mature means that other therapies are now available. A second limitation is that T3 patients may now profit from watchful waiting instead of androgen-deprivation therapy. CONCLUSIONS: Noninferiority of IHT in terms of survival and its association with better sexual activity than continuous therapy suggest that IHT should be considered for use in routine clinical practice.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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It is known that during sex differentiation, fetal androgens are critical determinants of the male phenotype. Although testosterone is necessary for normal development of male sexual behavior, perinatal androgen treatment can result in disruption of normal male sexual reproduction. Pregnant Wistar rats were administered either corn oil (vehicle) or testosterone propionate at 0.2 mg/kg from gestational day 12 until the end of lactation and the reproductive function of male offspring was evaluated at 90 (adulthood) and 270 (middle age) days of age. Perinatal androgenization in the rat provoked a reduction in sperm production and reserves in adulthood that did not affect fertility and did not persist at more advanced ages, as shown by the results at post-natal day 270. If perinatal androgenization promotes similar effects in humans of reproductive age, the results of the present work can impact male reproduction health, given the less efficient spermatogenesis and lower sperm reserves in the human epididymis, compared to rodents. © Georg Thieme Verlag KG Stuttgart. New York.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The pathological finding of testicular metastasis in cases of disseminated prostatic adenocarcinoma is rare, but was more frequently reported in the past, when bilateral castration was performed more often. The existence of skin and subcutaneous metastasis adds a worse prognosis, because generally it is sign of advanced disease with an average survival time of less than one year. The synchronous occurrence of such metastasis has not been described previously, neither their association to neuroendocrine differentiation. The presence of such differentiation of prostatic adenocarcinoma represents a very unfavorable prognostic factor, as suggested in recent literature. Herein, we discuss the case of a 53 year old man, who presented with macroscopic hematuria and frequency associated to several painless subcutaneous nodules in left axilla and shoulder, as well as in the lower abdominal wall. The right testis was painful, endured and on rectal examination, the prostate was diffusely enlarged. Serum PSA was elevated, reaching 1760 ng/ml and prostatic biopsy disclosed a Gleason 10 prostatic adenocarcinoma with neuroendocrine differentiation. The same pathological pattern was detected in the right testis and in all subcutaneous nodules, documented by positive staining of chromogranin, a marker of neuroendocrine cells. He was submitted to a prostate tunnelization and maximal androgen blockade plus adjuvant chemotherapy, nevertheless, he died 5 months latter.

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Pós-graduação em Ciências Biológicas (Farmacologia) - IBB

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The androgen receptor (AR) is expressed in 60-80% of breast cancers (BC) across all molecular phenotypes, with a higher incidence in oestrogen receptor positive (ER+) BC compared to ER negative tumours. In ER+ disease, AR-expression has been linked to endocrine resistance which might be reversed with combined treatment targeting ER and AR. In triple negative BCs (TNBC), preclinical and clinical investigations have described a subset of patients that express the AR and are sensitive to androgen blockade, providing a novel therapeutic target. Enzalutamide, a potent 2nd generation anti-androgen, has demonstrated substantial preclinical and clinical anti-tumour activity in AR+ breast cancer. Short-term preoperative window of opportunity studies are a validated strategy for novel treatments to provide proof-of-concept and define the most appropriate patient population by directly assessing treatment effects in tumour tissue before and after treatment. The ARB study aims to assess the anti-tumour effects of enzalutamide in early ER+ breast cancer and TNBC, to identify the optimal target population for further studies and to directly explore the biologic effects of enzalutamide on BC and stromal cells. Methods: ARB is an international, investigator sponsored WOO phase II study in women with newly diagnosed primary ER+ BC or AR+ TNBC of ≥ 1cm. The study has two cohorts. In the ER+ cohort, postmenopausal patients will be randomised 2:1 to receive either enzalutamide (160mg OD) plus exemestane (50mg OD) or exemestane (25mg OD). In the TNBC cohort, AR+ will receive single agent treatment with enzalutamide (160mg OD). Study treatment is planned for 15–29 days, followed by surgery or neo-adjuvant therapy. Tissue and blood samples are collected before treatment and on the last day of study treatment. The primary endpoint is inhibition of tumour-cell proliferation, as measured by change in Ki67 expression, determined centrally by 2 investigators. Secondary endpoints include induction of apoptosis (Caspase3), circulating hormone levels and safety. ARB aims to recruit ≈235 patients from ≈40 sites in the UK, Germany, Spain and USA. The study is open to recruitment.

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Exposure to environmental chemicals may contribute to reproductive disorders, especially when it occurs in critical periods of development. The female reproductive system can be a target for androgens derived from environmental contaminants or pathological conditions. The purpose of this study was to assess the long-term effects of androgens on uterine tissue after maternal exposure limited to the time of gestation and lactation. Pregnant Wistar rats were treated with testosterone propionate (TP) at 0.05. mg/kg, 0.1. mg/kg, 0.2. mg/kg or corn oil (vehicle), s.c., from gestational day 12 until the end of lactation. The results show changes in the pattern of expression of receptors for estrogen, progesterone, and androgen at all doses tested, and decreases in both apoptosis and cell proliferation indices at 0.1 and 0.2. mg/kg. We conclude that early TP exposure, under these experimental conditions, causes changes in cellular and molecular parameters that are essential for normal uterine function in the adult. © 2013 Elsevier Inc.

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Androgen exposure during sexual development induces alterations in steroidal target tissues. The objective of this study was to evaluate the uterine responsiveness to estradiol after perinatal androgenization. Pregnant Wistar rats were exposed to corn oil or testosterone propionate at 0.05, 0.1, or 0.2 mg/kg from gestational day 12 until postnatal day 21. Female offspring was challenged with estradiol (E2 ) after weaning (0.4 mg/kg) and at adulthood (10 or 100 µg/day), when the pituitary response was also evaluated. At adulthood, control and 0.05 mg/kg groups presented a uterine weight increment when exposed to 100 µg/day of E2 , 0.1 mg/kg group only responded to 10 µg/day of E2 , and the 0.2 mg/kg group showed increased uterine weight at both doses. The pituitary weight was similarly increased after estradiol stimulation in all experimental groups. In conclusion, testosterone propionate exposure induced an abnormal stimulation of uterine tissue growth by estrogen stimulus without affecting pituitary response. More studies are needed to clarify whether these alterations are capable of impairing the reproductive capacity of the female tract. © 2015 Wiley Periodicals, Inc. Environ Toxicol, 2015.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The gerbil is a rodent considered a good model for studies of prostatic morphophysiology under different experimental conditions. Studies involving castration and steroidal blockers of aged gerbils showed that the glandular epithelium persists after long-term therapy, preventing the organ atrophy. Thus, the objective of this study was to evaluate the phenotypic characteristics and behavior of prostatic epithelial cells that remained after different periods of hormone ablation in aged gerbils. The identification of elements that influenced the survival of this cell type was performed by morphometric, nuclear phenotypes, ultrastructural and immune histochemical analysis. The most significant responses to treatment, by analyzing morphometric features, were observed during the first three time points (day 1, day 3, and day 7), after which there appeared to be an adjustment of the gland to the hormone ablation. All treatments led to changes in the state of chromatin condensation, DNA methylation pattern and phenotypic changes indicated cell senescence. Additionally, an increase in the basal cells seemed to guarantee self-renewal properties to the epithelium. These data indicate that changes occur at many levels, including gene expression and nuclear architecture in the epithelial cells, when aging and steroidal blockade are associated. These aspects are important when considering castration-resistant prostate cancer, a malignant tumor posing difficult therapeutic intervention. © 2013 Elsevier GmbH. All rights reserved.

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Association between hypertension and bladder symptoms has been described. We hypothesized that micturition dysfunction may be associated with renin-angiotensin system (RAS) acting in urethra. The effects of the anti-hypertensive drugs losartan (AT1 antagonist) and captopril (angiotensin-converting enzyme inhibitor) in comparison with atenolol (β1-adrenoceptor antagonist independently of RAS blockade) have been investigated in bladder and urethral dysfunctions during renovascular hypertension in rats. Two kidney-1 clip (2K-1C) rats were treated with losartan (30 mg/kg/day), captopril (50mg/kg/day) or atenolol (90 mg/kg/day) for eight weeks. Cystometric study, bladder and urethra smooth muscle reactivities, measurement of cAMP levels and p38 MAPK phosphorylation in urinary tract were determined. Losartan and captopril markedly reduced blood pressure in 2K-1C rats. The increases in non-voiding contractions, voiding frequency and bladder capacity in 2K-1C rats were prevented by treatments with both drugs. Likewise, losartan and captopril prevented the enhanced bladder contractions to electrical-field stimulation (EFS) and carbachol, along with the impaired relaxations to β-adrenergic-cAMP stimulation. Enhanced neurogenic contractions and impaired nitrergic relaxations were observed in urethra from 2K-1C rats. Angiotensin II also produced greater urethral contractions that were accompanied by higher phosphorylation of p38 MAPK in urethral tissues of 2K-1C rats. Losartan and captopril normalized the urethral dysfunctions in 2K-1C rats. In contrast, atenolol treatment largely reduced the blood pressure in 2K-1C rats but failed to affect the urinary tract smooth muscle dysfunction. The urinary tract smooth muscle dysfunction in 2K-1C rats takes place by local RAS activation irrespective of levels of arterial blood pressure.