48 resultados para Letrozole


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Introduction: en oncologie apparaissent sur le marché depuis quelques années de nouveaux traitements en formulation orale facilitant l'administration et améliorant la qualité de vie du patient mais augmentant le risque de non adhésion et d'erreurs de posologie. L'observation par MEMS® (Medication Event Monitoring System) permet le suivi et l'encadrement du traitement oral et par le biais d'entretiens semi structurés menés par le pharmacien, ouvre la discussion sur les problèmes révélés par cette prise en charge. Méthode: étude non randomisée prospective uni centrique regroupant 50 patients inclus dans 3 groupes de traitements oncologiques oraux courants (capecitabine, letrozole/exemestane, imatinib/sunitinib) bénéficiant d'un suivi oncologique classique et équipés d'un MEMS® pour un an maximum. La persistance et la qualité d'exécution sont les deux paramètres mesurés grâce aux données récoltées électroniquement. Les entretiens sont dédiés à la prévention de la non adhésion et à la gestion des effets secondaires médicamenteux. La satisfaction est évaluée par un questionnaire à la fin du suivi. Résultats: à ce jour 38 patients ont été inclus dans l'étude. Les données complètes sont disponibles pour les 19 premiers patients dont 10 sous capecitabine et 9 sous letrozole/exemestane. Dans ce collectif l'âge médian est de 66 ans avec une majorité de femmes (11:8). La persistance à 10 jours est de 85% et la qualité d'exécution de 99%. Les toxicités observées supérieures à grade 1 sont 1 syndrome mains-pieds (G3) et 1 syndrome coronarien aigu (G3). Le questionnaire de fin de suivi relève une satisfaction de 85% des patients pour les entretiens proposés (57% utiles, 28% très utiles, 15% inutiles) et le succès quant à l'intégration du MEMS® dans leur quotidien (57% très facile, 43% facile). Conclusion: la persistance et la qualité d'exécution observées dans notre collectif sont excellentes. La satisfaction retrouvée auprès des patients reflète le besoin d'un soutien complémentaire face à la complexité de la maladie oncologique. La gestion pluridisciplinaire profite tant aux patients qu'au binôme médecin-pharmacien par l'amélioration de la communication globale entre les divers acteurs et par l'identification précoce des risques de non adhésion. La poursuite de cette étude et l'analyse des futures données permettra de mesurer le réel impact de notre intervention et de justifier le bénéfice pour des patients sous traitement similaire.

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Purpose: Letrozole (LET) has recently been shown to be superior to tamoxifen for postmenopausal patients (pts). In addition, LET radiosensitizes breast cancer cells in vitro. We conducted a phase II randomized study to evaluate concurrent and sequential radiotherapy (RT)-LET in the adjuvant setting. We present here clinical results with a minimum follow-up of 24 months. Patients and Methods: Postmenopausal pts with early-stage breast cancer were randomized after conservative surgery to either: A) concurrent RT-LET (LET started 3 weeks before the first day of RT) or B) sequential RT-LET (LET started 3 weeks after the end of RT). Whole breast RT was delivered to a total dose of 50 Gy. A 10-16 Gy boost was allowed according to age and pathological prognostic factors. Pts were stratified by center, adjuvant chemotherapy, boost, and radiation-induced CD8 apoptosis (RILA). RILA was performed before RT as previously published (Ozsahin et al. Clin Cancer Res, 2005). An independent monitoring committee reviewed individual safety data. Skin toxicities were evaluated by two different clinicians at each medical visit (CTCAE v3.0). Lung CT-scan and functional pulmonary tests were performed regularly. DNA samples were screened for SNPs in candidate genes as recently published (Azria et al., Clin Cancer Res, 2008). Results: A total of 150 pts were randomized between 01/05 and 02/07. Median follow-up is 26 months (range, 3-40 months). No statistical differences were identified between the two arms in terms of mean age; initial TNM; median surgical bed volume; post surgical breast volume. Chemotherapy and RT boost were delivered in 19% and 38% of pts, respectively. Nodes received 50 Gy in 23% of patients without differences between both arms. During RT and within the first 6 weeks after RT, 10 patients (6.7%) presented grade 3 acute skin dermatitis during RT but no differences were observed between both arms (4 and 6 patients in arm A and B, respectively). At 26 month of follow-up, grade 2 and more radiation-induced subcutaneous fibrosis (RISCF) was present in 4 patients (3%) without any difference between arm A (n = 2) and B (n = 2), p=0.93. In both arms, all patients that presented a RICSF had a RILA lower than 16%. Sensitivity and specificity were 100% and 39%, respectively.No acute lung toxicities were observed and quality of life was good to excellent for all patients.SNPs analyses are still on-going (Pr Rosenstein, NY). Conclusion: Acute and early late grade 2 dermatitis were similar in both arms. The only factor that influenced RISCF was a low radiation-induced lymphocyte apoptosis yield. We confirmed prospectively the capacity of RILA for identifying hypersensitive patients to radiation. Indeed, patients with RILA superior to 16% did not present late effects to radiation and confirmed the first prospective trial we published in 2005 (Ozsahin et al., Clin Cancer Res).

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The incidence of ciliated cells in the prostate gland of the female gerbil (Meriones unguiculatus) is uncommon and apparently becomes more frequent during androgen (testosterone cypionate) and anti-estrogen (letrozole) endocrine therapies. To evaluate the effects of such drug therapies on the induction of ciliogenesis in the glandular epithelium of female prostate glands, adult female gerbils aged 90 days were treated for 14 days with testosterone and letrozole after which their prostate glands were removed for histological, ultrastructural, and serological analyses. The cytodifferentiation of the ciliated phenotype in the alveolar epithelium became more frequent after both the testosterone and the letrozole treatments. The ciliogenesis phenomenon of the epithelial cells in the prostate gland of female gerbils thus appears to be induced by variations in the increase of androgen levels.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Obesity affects sex hormone secretion, which can negatively influence prostatic structure, homeostasis, and disease. This investigation aimed to evaluate the repercussions of obesity induced by a high-fat diet on the rat prostate, with or without treatment with the aromatase inhibitor, Letrozole. Adult Wistar rats were fed a high-fat diet (20% saturated fat, O) for 15 weeks to induce obesity or received a balanced diet (4% fat, C). Then, a group of C and O rats were daily treated with Letrozole (1 mg/kg b.w. per day) for 2 weeks (CL and OL, respectively). Subsequently, ventral prostate was processed for analysis by transmission electron microscopy, immunohistochemistry, and Western blotting. Obesity decreased 70% of the testosterone plasma level. The prostate showed epithelial atrophy and dilated acini in the intermediate portion and epithelial wrinkling in the distal tips. The relative frequency of smooth muscle alpha-actin in the O group increased by 67%. Ultrastructurally, epithelial cells in obese animals presented altered secretory organelles, lipid droplets, and thicker subjacent fibromuscular layer. Letrozole treatment caused a partial restoration of the prostatic changes caused by obesity. Obesity increased the prostatic content of fibroblast growth factor-2 (FGF-2) by 150%, and Letrozole treatment increased this protein even more in the control and obese groups. This investigation shows that obesity provokes structural and ultrastructural changes in the epithelium of rat prostate; these changes might affect gland homeostasis and physiology. The epithelial and smooth muscle cell hyperplasia and increased FGF-2 expression observed in this experimental model of obesity/insulin-resistance might explain the high frequency of benign prostatic hyperplasia in insulin-resistant men.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The present study examined the effects of letrozole exposure during brain sexual differentiation on endocrine, behavioural and neurochemical parameters in male rat descendants. Pregnant female rats received 1 mg kg(-1) day(-1) letrozole or vehicle by oral gavage on gestational Days 21 and 22. Exposure to letrozole reduced anogenital distance in males on postnatal Day (PND) 22. At adulthood (PND 75), plasma testosterone levels and hypothalamic dopaminergic activity were increased, but sexual competence was impaired, because fewer successful sexual behaviours (mount, intromission and principally ejaculation) were observed. The impairment of reproductive function by prenatal exposure to an aromatase inhibitor reinforces the importance of adequate oestrogenic activity during perinatal sexual differentiation for complete masculinisation of the hypothalamus.

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The effects of maternal exposure to aromatase inhibitor during the perinatal period of sexual brain differentiation were studied. The fertility was assessed in adult, male rat offspring of aromatase inhibitor-treated dams. The following results were obtained: (1) Sexual maturation, body weight, and wet weights of testis, pituitary, seminal vesicle, ventral prostate, and levatori ani muscle were unchanged at adult life. (2) Fifty percent of the animals were able to mate with normal females, which became pregnant but exhibited an increased number of preimplantation loss. (3) There was a decrease in the number of spermatozoa found in the testes and in the daily sperm production. (4) Of those, 25% of the male rats treated with aromatase inhibitor did not present male sexual behavior, showing female behavior when pretreated with estrogen. These results indicate that perinatal exposure to aromatase inhibitor during the critical period of male brain sexual differentiation has a long-term effect on the reproductive physiology and behavior of male rats.

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Two experiments were performed using the aromatase inhibitor (AI) letrozole (100mg/kg) to promote sex change, from female-to-male, in protogynous dusky grouper. One experiment was performed during the breeding season (spring) and the other at the end of the breeding season (summer). During the spring, AI promoted sex change after 9weeks and the sperm produced was able to fertilize grouper oocytes. During the summer, the sex change was incomplete; intersex individuals were present and sperm was not released by any of the animals. Sex changed gonads had a lamellar architecture; cysts of spermatocytes and spermatozoa in the lumen of the germinal compartment. In the spring, after 4weeks, 11ketotestosterone (11KT) levels were higher in the AI than in control fish, and after 9weeks, coincident with semen release, testosterone levels increased in the AI group, while 11KT returned to the initial levels. Estradiol (E2) levels remained unchanged during the experimental period. Instead of decreasing throughout the period, as in control group, 17 α-OH progesterone levels did not change in the AI-treated fish, resulting in higher values after 9weeks when compared with control fish. fshβ and lhβ gene expression in the AI animals were lower compared with control fish after 9weeks. The use of AI was effective to obtain functional males during the breeding season. The increase in androgens, modulated by gonadotropins, triggered the sex change, enabling the development of male germ cells, whereas a decrease in E2 levels was not required to change sex in dusky grouper. © 2013 Elsevier Inc.

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In this study, we evaluated the effects of obesity and insulin resistance induced by a high-fat diet on prostate morphophysiology, focusing on cell proliferation, expression of androgen (AR) and estrogen receptors (ER) and proteins of the insulin signaling pathway. Adult male Wistar rats were fed a high-fat diet (20% fat) for 15 weeks, whereas control animals received a balanced diet (4% fat). Both groups were then divided and treated for 2 weeks with 1 mg/kg body weight/day of the aromatase inhibitor letrozole or vehicle only. The ventral prostate was analyzed with immunohistochemical, histopathological, stereological, and Western blotting methods. Obese rats showed insulin resistance, hyperinsulinemia, and reduced plasma testosterone levels. The incidence of prostatic intraepithelial neoplasia (PIN) was 2.7 times higher in obese rats and affected 0.4% of the gland compared with 0.1% PIN areas found in control rats. Obesity doubled cell proliferation in both prostate epithelium and stroma. AR content decreased in the prostate of obese rats and estrogen receptor beta (ER beta) increased in this group. Protein levels of insulin receptor substrate 1 and protein kinase B diminished in the obese group, whereas phosphatidylinositol 3-kinase (PI3K) increased significantly. Most structural changes observed in the prostate of obese rats normalized after letrozole treatment, except for increased stromal cell proliferation and ER beta expression, which might be associated with insulin resistance. This experimental model of obesity and insulin resistance induced by a high-fat diet increases cell proliferation in rat prostate. Such alterations are associated with decreased levels of AR and increased ER beta and PI3K proteins. This change can facilitate the establishment of proliferative lesions in rat prostate.

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ZusammenfassungrnrnrnZwei 18F-markierte Derivate des Aromataseinhibitors Letrozol 5, [18F]FML 17 und [18F]FEL 18, sowie die benötigten Markierungsvorläufer sollten im Rahmen dieser Arbeit hergestellt werden. Die Referenzverbindungen [19F]FML 17 und [19F]FEL 18 wurden synthetisiert und bei Novartis bereits auf ihre in vitro Eigenschaften untersucht. Nach erfolgreicher Radiomarkierung der beiden Derivate sollten erste in vitro und in vivo Untersuchungen mit den radiomarkierten Verbindungen durchgeführt werden. Zusätzlich zu diesen beiden Derivaten wurde ein drittes radiofluoriertes Letrozolderivat, [18F]FPL 19, und der entsprechende Markierungsvorläufer synthetisiert.rnrnZur Direktmarkierung von [18F]FML 17 mit [18F]Fluorid wurden drei Markierungsvorläufer mit verschiedenen Abgangsgruppen (TosMV-FML 7, MesMV-FML 8 and BrMV-FML 20) in 68 %, 66 % und 30 % Ausbeute hergestellt. Die Radiomarkierung von TosMV-FML 7 lieferte [18F]FML 17 in max. 30 % Ausbeute. Die Markierungsausbeuten waren unstabil und nicht reproduzierbar. Versuche, die Markierungsausbeuten durch Variation von Reaktionsparametern wie Temperatur, Lösungsmittel und Basensystem zu optimieren und zu stabilisiern, blieben erfolglos. Die Radiomarkierungsversuche der beiden anderen Markierungsvorläufer, MesMV-FML 8 und BrMV-FML 20, ergaben ebenfalls nicht das gewünschte Produkt [18F]FML 17.rnrnUm radiofluoriertes [18F]FEL 18 zu erhalten, wurden zwei Strategien untersucht. Ein Ansatz ist eine 18F-Direktmarkierung geeigneter Markierungsvorläufer, die andere Strategie eine 18F Fluoralkylierung von Letrozol 5 mit prosthetischen Gruppen wie 2-[18F]Fluorethyltosylat ([18F]FETos) oder 1-Brom-2-[18F]fluorethan ([18F]BFE). Im letzten Schritt der Synthese der Direktmarkierungsvorläufer konnten die benötigten Markierungsvorläufer nicht isoliert werden. Stattdessen wurde die Bildung von Nebenprodukten beobachtet. Die Radiomarkierung von Letrozol 5 mit [18F]FETos oder [18F]BFE ergab kein [18F]FEL 18. Im Verlauf der Radiomarkierung wurde die Bildung eines nicht radioaktiven Nebenproduktes beobachtet. Die Verwendung von Iodid-Salzen zur in situ-Bildung von 1-[18F]Fluor-2-iodethan, eines noch reaktiveren Fluoralkylierungsagens, konnte das Ergebnis der Radiomarkierungsreaktionen nicht verbessern.rnrnDie Synthese des dritten Letrozolderivates, [18F]FPL 19, verlief erfolgreich. Der benötigte Markierungsvorläufer zur Direktmarkierung mit 18F, TosMV-FPL 16, konnte in 59 % Ausbeute hergestellt werden. Das Einfügen einer dritten Methylengruppe zwischen dem Letrozolrest und dem radioaktiven Label führte zu stabilen, reproduzierbaren radiochemischen Ausbeuten zwischen 30 % und 45 %.rnrnDa die radiochemischen Ausbeuten der 18F-Direktmarkierung des TosMV-FML 7 zur Herstellung von [18F]FML 17 nicht stabilisiert werden konnten, wurden keine weitereführenden in vitro oder in vivo Untersuchungen vorgenommen. Die radiomarkierte Verbindung [18F]FEL 18 konnte über keine der beiden Markierungsstrategien synthetisiert werden. Daher konnten keine in vitro oder in vivo Experimente durchgeführt werden. Die erfolgreiche Radiomarkierung des neuen dritten Letrozolderivates, [18F]FPL 19, macht nun weitere in vitro und in vivo Testungen der 19F Referenzverbindung und des 18F-Analogs erforderlich. Ähnliche Eigenschaften wie für die beiden bereits evaluierten Verbindungen, FML 17 and FEL 18, können erwartet werden.rnrnDiese Arbeit entstand im Rahmen einer Kooperation zwischen der Novartis International AG, Basel und der Johannes Gutenberg-Universität Mainz.rnrn

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Background:In the BIG 1-98 trial objective cognitive function improved in postmenopausal women 1 year after cessation of adjuvant endocrine therapy for breast cancer. This report evaluates changes in subjective cognitive function (SCF).Methods:One hundred postmenopausal women, randomised to receive 5 years of adjuvant tamoxifen, letrozole, or a sequence of the two, completed self-reported measures on SCF, psychological distress, fatigue, and quality of life during the fifth year of trial treatment (year 5) and 1 year after treatment completion (year 6). Changes between years 5 and 6 were evaluated using the Wilcoxon signed-rank test. Subjective cognitive function and its correlates were explored.Results:Subjective cognitive function and the other patient-reported outcomes did not change significantly after cessation of endocrine therapy with the exception of improvement for hot flushes (P=0.0005). No difference in changes was found between women taking tamoxifen or letrozole. Subjective cognitive function was the only psychosocial outcome with a substantial correlation between year 5 and 6 (Spearman's R=0.80). Correlations between SCF and the other patient-reported outcomes were generally low.Conclusion:Improved objective cognitive function but not SCF occur following cessation of adjuvant endocrine therapy in the BIG 1-98 trial. The substantial correlation of SCF scores over time may represent a stable attribute.British Journal of Cancer advance online publication, 24 April 2012; doi:10.1038/bjc.2012.156 www.bjcancer.com.

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BACKGROUND: Aromatase inhibitors are considered standard adjuvant endocrine treatment of postmenopausal women with hormone receptor-positive breast cancer, but it remains uncertain whether aromatase inhibitors should be given upfront or sequentially with tamoxifen. Awaiting results from ongoing randomized trials, we examined prognostic factors of an early relapse among patients in the BIG 1-98 trial to aid in treatment choices. PATIENTS AND METHODS: Analyses included all 7707 eligible patients treated on BIG 1-98. The median follow-up was 2 years, and the primary end point was breast cancer relapse. Cox proportional hazards regression was used to identify prognostic factors. RESULTS: Two hundred and eighty-five patients (3.7%) had an early relapse (3.1% on letrozole, 4.4% on tamoxifen). Predictive factors for early relapse were node positivity (P < 0.001), absence of both receptors being positive (P < 0.001), high tumor grade (P < 0.001), HER-2 overexpression/amplification (P < 0.001), large tumor size (P = 0.001), treatment with tamoxifen (P = 0.002), and vascular invasion (P = 0.02). There were no significant interactions between treatment and the covariates, though letrozole appeared to provide a greater than average reduction in the risk of early relapse in patients with many involved lymph nodes, large tumors, and vascular invasion present. CONCLUSION: Upfront letrozole resulted in significantly fewer early relapses than tamoxifen, even after adjusting for significant prognostic factors.