Research Progress in the Role of Tamoxifen in Nervous System and Cognitive Function / 中国医学科学院学报

Neurological diseases include a variety of neurodegenerative diseases and other brain damage diseases.The treatment schemes for neurological diseases are still in research.The existing clinical and basic studies have confirmed that traditional estrogen therapy has certain protective effect on the nervous system,while it increases the risk of breast or endometrial cancer.The emergence of the selective estrogen receptor modulators (SERMs) can avoid the above mentioned problems.The available studies have confirmed the protective effect of tamoxifen as a SERM on the nervous system.This paper reviews the role and functioning mechanisms of tamoxifen in the nervous system and cognitive function,aiming to provide guidance for the future application of tamoxifen in the treatment of neurological diseases and the improvement of cognitive function.

Cáncer de mama avanzado receptor de estrógeno positivo: manejo sistémico actual / Systemic therapy for estrogen receptor positive advanced breast cancer

El cáncer de mama es la primera causa de muerte por cáncer en mujeres chilenas. Mientras la mayoría de las personas logra curarse de esta enfermedad, un 5% de los casos se presenta inicialmente con enfermedad avanzada y hasta un 20-30% de pacientes con enfermedad localizada pueden sufrir recurrencias sistémicas. La mayoría de las neoplasias mamarias son dependientes del estímulo estrogénico, de allí que la deprivación de estrógenos es la principal estrategia terapéutica. Recientemente, el uso de terapias molecularmente dirigidas en combinación con la terapia endocrina ha logrado mejorar los resultados de sobrevida del cáncer de mama avanzado, con menos efectos colaterales que aquellos producidos por la quimioterapia convencional. El conocimiento de los mecanismos de acción de estas nuevas terapias, sus toxicidades, vías de resistencia y selección de pacientes para lograr los mejores beneficios terapéuticos son aspectos relevantes en el manejo de la enfermedad. Presentamos una revisión del estado actual del manejo del cáncer de mama metastásico hormonodependiente con enfásis en el uso de terapias endocrinas combinadas con terapias moleculares.

Breast cancer is the leading cause of cancer death in Chilean women. While most patientes are cured, five percent of cases present with advanced disease initially and up to 20-30% of patients with localized disease may suffer systemic recurrences. The majority of breast neoplasms are dependent on the estrogenic stimulus, hence the deprivation of estrogen is the main therapeutic strategy. Recently, the use of molecular targeted therapies in combination with endocrine therapy has been successful in improving the survival outcomes of advanced breast cancer, with fewer side effects than those produced by conventional chemotherapy. Knowledge of the mechanisms of action of these new therapies, their toxicities, resistance pathways and patient selection to achieve the best therapeutic benefits are relevant aspects in the management of the disease. We present a review of the current state of management of hormone-dependent metastatic breast cancer with emphasis on the use of endocrine therapies combined with molecular therapies.

Using agents that suppress bone remodeling to treat or prevent joint disease: quo vadis?

Treatment of osteoarthritis (OA) with antiremodeling agents has had a mixed record of results. It is likely that remodeling suppression is only effective when used in the early phases of OA, before significant progression. Animal and human studies largely bear this out. Treatment of young mice with a RANKL inhibitor suppresses bone resorption and prevents OA progression. Likewise, bisphosphonate treatments in rodents and rabbits with induced injury or inflammatory arthritis, reduced cartilage degeneration when administered preemptively, but later administration did not. The increased prevalence of OA in women after the menopause, and presence of estrogen receptors in joint tissues, suggests that treatment with estrogens or Selective Estrogen Receptor Modulators may be effective. However, in clinical trials of knee and hip, results show decreased or increased risk for OA, or no effect. Raloxifene had positive effects in animal models, but no effect in human studies. More recent potential treatments such as strontium ranelate or cathepsin-K inhibitors may be effective, but may work directly on the cartilage rather than through their well-known effects on bone. The conclusion from these studies is that anti-remodeling agents must be administered pre-emptively or in the very early stages of disease to be effective. This means that better imaging techniques or identification of early structural changes in bone that occur before progressive cartilage destruction must be developed. (AU)

Pharmacological management of osteogenesis

Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases.

An overview on the treatment of postmenopausal osteoporosis / Uma visão geral sobre o tratamento da osteoporose pós-menopausa

Osteoporosis is a worldwide health problem related to the aging of the population, and it is often underdiagnosed and undertreated. It is related to substantial morbidity, mortality and impairment of the quality of life. Estrogen deficiency is the major contributing factor to bone loss after menopause. The lifetime fracture risk at 50 years of age is about 50% in women. The aim of the treatment of osteoporosis is to prevent fractures. Non-pharmacological treatment involves a healthy diet, prevention of falls, and physical exercise programs. Pharmacological treatment includes calcium, vitamin D, and active medication for bone tissue such, as anti-resorptives (i.e., SERMs, hormonal replacement therapy, bisphosphonates, denosumab), bone formers (teriparatide), and mixed agents (strontium ranelate). Bisphosphonates (alendronate, risedronate, ibandronate, and zoledronate) are the most used anti-resorptive agents for the treatment of osteoporosis. Poor compliance, drug intolerance, and adverse effects can limit the benefits of the treatment. Based on the knowledge on bone cells signaling, novel drugs were developed and are being assessed in clinical trials.

A osteoporose é um problema de saúde mundial relacionada com o envelhecimento da população e muitas vezes é subdiagnosticada e subtratada. Relaciona-se à significativa morbidade, mortalidade e redução da qualidade de vida. A deficiência de estrogênio é o principal fator que contribui para a perda óssea após a menopausa. O risco de fratura a partir dos 50 anos de idade é de cerca de 50% em mulheres. O objetivo do tratamento da osteoporose é a prevenção de fraturas. O tratamento não farmacológico envolve uma dieta saudável, prevenção de quedas e de programas de exercícios físicos. O tratamento farmacológico inclui cálcio, vitamina D e medicação ativa em tecido ósseo, tais como antirreabsortivos (SERMs, terapia de substituição hormonal, bifosfonatos, denosumabe), formadores de osso (PTH e análogos) e agentes mistos (ranelato de estrôncio). Os bisfosfonatos (alendronato, risedronato, ibandronato e zoledronato) são os mais utilizados agentes antirreabsortivos para o tratamento da osteoporose. A baixa aderência, a intolerância medicamentosa e os efeitos adversos podem limitar os benefícios do tratamento. Com base no conhecimento da sinalização entre as células ósseas, novos medicamentos foram desenvolvidos e estão sendo avaliados em ensaios clínicos.

Tamoxifeno y afecciones endometriales en pacientes con cáncer de mama / Tamoxifen and endometrial disease in patients with breast cancer

Los objetivos fueron evaluar la prevalencia de afecciones endometriales en pacientes tratadas con tamoxifeno (TAM) y analizar los aspectos epidemiológicos, ecográficos, histeroscópicos e histopatológicos. Desde enero de 1999 a diciembre 2008 se estudiaron 152 pacientes con cáncer de mama tratadas con TAM (20 mg/día), sintomáticas (con sangrado) o asintomáticas, pre y postmenopáusicas, incluidas en forma consecutiva. El diseño fue prospectivo y observacional. Los métodos diagnósticos usados fueron ecografía transvaginal, histeroscopía y biopsia. Las pacientes fueron seguidas durante 5 años con ecografía cada 12 meses e histeroscopia con biopsia en casos que lo justificaran. Edad: 62.76 ± 10.24 años y tiempo de tratamiento: 36.2 ± 19.9 meses. El adenocarcinoma se observó en 3/87 (3.45%) pacientes con factores de riesgo y en 1/65 (1.54%) sin ellos (RA: 1.91, IC 95% 1.88 a 1.94). Las afecciones benignas se hallaron en 148 pacientes (97.37% y los adenocarcinomas en 4 (2.63%),1 en un pólipo de aspecto benigno. Los 4 se observaron en mujeres postmenopáusicas (2 asintomáticas) con grosor endometrial igual o mayor a 16 mm. El riesgo de cáncer fue significativamente mayor en sintomáticas (2.36 versus 0.42 en asintomáticas). Tres adenocarcinomas se detectaron entre 24 y 48 meses del tratamiento. Recomendamos un seguimiento con ecografía transvaginal de las pacientes asintomáticas, resección de los pólipos evaluando factores de riesgo y tiempo de exposición, en especial luego de los 24 meses. Consideramos aceptable un cut-off = 10 mm en el grosor del endometrio en postmenopáusicas asintomáticas para realizar histeroscopía y biopsia.

The objectives were to evaluate prevalence of endometrial disease in patients treated with tamoxifen (TAM) and analyze the epidemiological, sonographic, hysteroscopic and histopathological findings. From January 1999 to December 2008, 152 breast cancer patients treated with TAM (20 mg/day), symptomatic (with bleeding) or asymptomatic, pre- and postmenopausal, were included consecutively in a prospective and observational follow-up study Diagnostic methods were (TV) transvaginal ultrasound, hysteroscopy and curettage biopsy. TV ultrasound was performed every 12 months for 12 to 60 months. The patients´ age were 62.76 years ± 10.24 the TAM-time: 36.24 ± 19. Adenocarcinoma was observed in 3/87 patients (3.45%) with risk factors and in 1/65 (1.54%) without them (RA 1.91, IC 95% 1.88-1.94). We found benign disease in 148 patients (97.37%) and adenocarcinomas in 4 (2.63%), one within a polyp. The 4 adenocarcinomas were detected in postmenopausal women (2 asymptomatic) with endometrial thicknesses equal or greater than 16 mm. The cancer risk was significantly increased in symptomatic (2.36 versus 0.42 in asymptomatic). Three adenocarcinomas were observed between 24 and 48 months of treatment. In conclusion, we suggest an adequate transvaginal ultrasound monitoring of asymptomatic patients treated with TAM, with removal of polyps, because atypia can be present hidden within, considerin risk factors and exposure time. We suggest as an acceptable cut-off = 10 mm in asymptomatic postmenopausal patients.

A randomized, double-blind, placebo-controlled trial of ormeloxifene in breast pain and nodularity.

Background. Breast pain and non-discrete breast nodularity are common in women. Methods. We did a randomized, double-blind, placebocontrolled trial of oral ormeloxifene 30 mg, a selective oestrogen receptor modulator (SERM) or placebo twice a week for 3 months in 20–50-year-old women with breast pain with or without lumpiness. Women with a discrete benign lump or cancer were excluded from the study. Serial assessments of pain on a visual analogue scale and nodularity grade on a 5-point ordinal Lucknow–Cardiff scale were done. A total of 151 patients were randomly allocated to two interventions using a block size of 4. Results. Of the 151 patients, 121 (active 57, placebo 64) were available for efficacy analysis. The mean pain level showed a systematic downward trend over five visits (F=105.23, p<0.0001) that significantly reduced in the active group compared to that in the placebo group (F=18.66, p<0.0001). The patterns of variation in pain over time for the individual groups differ from the overall mean pattern for the two groups and thus from one another (F=44.43, p<0.0001). Cumulative frequencies of breast nodularity grades during successive visits showed significant improvement (p=0.001) compared to placebo at the end of the third month. The effect of the active drug persisted till the completion (6 months) of treatment (p<0.001). At the last visit, 93.3% of women in the active group had grade 2 or lower nodularity as compared to 71.1% in the placebo group. Oligomenorrhoea alone was reported by 12 patients. Conclusion. Ormeloxifene showed significant efficacy for treating breast pain and nodularity.

Moduladores seletivos do receptor estrogênico: novas moléculas e aplicações práticas / Selective estrogen receptor modulators: new molecules and practical uses

Os moduladores seletivos do receptor de estrogênio são moléculas que se ligam ao receptor estrogênico com ações agonistas e antagonistas, em tecidos específicos. Eles apresentam efeitos estrogênicos e antiestrogênicos em vários órgãos, o que lhes permite diferentes atuações clínicas específicas. As diferenças nas estruturas moleculares conferem propriedades diferentes de ligação ao receptor-alvo, resultando em diferenças nos efeitos terapêuticos e adversos. Desde a descoberta dos primeiros compostos, há 50 anos, vários outros têm sido estudados e são usados frequentemente por ginecologistas, oncologistas e mastologistas. O raloxifeno é aprovado para a prevenção e o tratamento de osteoporose na pós-menopausa e para o câncer de mama receptor de estrogênio positivo; o tamoxifeno, para prevenção e tratamento do câncer de mama receptor de estrogênio positivo na pós-menopausa; e o clomifeno, primeiro modulador seletivo com receptor de estrogênio a ser estudado e empregado clinicamente, para infertilidade. Outras moléculas como bazedoxifeno, lasofoxifeno e arzoxifeno vêm sendo estudadas e vêm se mostrando como alternativas eficazes, algumas com menos efeitos colaterais

Selective estrogen receptor modulators are molecules that bind to estrogen receptor with agonistic and antagonistic actions in specific tissues. They exert estrogenic and anti-estrogenic effects in several organs, allowing them to perform differently in specific clinical situations. The differences in molecular structures provide different binding properties to the target receptor, resulting in differences in therapeutic and adverse effects. Since the discovery of the first compounds 50 years ago, several others have been studied and are often used by gynecologists and oncologists, and mastologists. Raloxifene is approved for preventing and treating osteoporosis in postmenopausal women and for treating estrogen receptor-positive breast cancer; tamoxifen is used for preventing and treating estrogen receptor-positive postmenopausal breast cancer; and clomiphene, the first selective estrogen receptor modulator to be studied and clinically employed, is used for infertility treatment. Other molecules such as bazedoxifene, lasofoxifene and arzoxifene have been studied and shown to be effective alternatives, some with fewer side effects

SERMs in the prevention and treatment of postmenopausal osteoporosis: an update / SERMs na prevenção e no tratamento da osteoporose pós-menopausa: uma atualização

Selective estrogen receptor modulators (SERMs) have the ability to bind the estrogen receptor (ER) and are known to confer ER agonist or antagonist effects depending on the target tissue. A number of newer SERMs, including bazedoxifene, lasofoxifene and ospemifene, are currently under clinical development for the prevention and treatment of postmenopausal osteoporosis and for other indications. Although the possibility of developing a single agent that has all of the desired characteristics of an ideal SERM seems to be unlikely, progress in the clinical development of SERMs targeted to the ER suggests that these newer compounds may have attributes that represent an improvement relative to existing SERMs. A new approach to menopausal therapy is the tissue selective estrogen complex or the pairing of a selective estrogen receptor modulator with estrogens. Further investigation will help to clarify relative benefits/risks of novel SERMs in development within specific indications.

Moduladores seletivos do receptor do estrogênio (SERMs) têm a habilidade de se ligar ao receptor de estrogênio (ER) e são conhecidos por conferir um efeito agonista ou antagonista sobre o tecido-alvo. Um número de novos SERMs, incluindo bazedoxifeno, lasofoxifeno e ospemifeno, está atualmente em desenvolvimento clínico para prevenção e tratamento da osteoporose pós-menopausa e para outras indicações. Embora a possibilidade de desenvolver um simples agente que tenha todas as características desejadas de um SERM ideal parece ser pouco provável, esses novos SERMs apresentam propriedades que indicam uma melhora em relação aos SERMs existentes. Uma nova opção terapêutica é o uso do complexo estrogênico do tecido seletivo ou a associação do SERM com estrogênios. Novos estudos ajudarão a rastrear os riscos e benefícios dos novos SERMs em desenvolvimento dentro das suas indicações específicas.

Terapia hormonal de reemplazo en prevención cardiovascular: ¿Dónde estamos parados? / Hormone replacement therapy and cardiovascular prevention: Where are we now?

Durante su edad fértil, la mujer sufre una incidencia de enfermedad cardiovascular ateroesclerótica (particularmente infarto de miocardio) significativamente inferior a la del hombre. Este beneficio desaparece progresivamente luego de la menopausia, hasta equilibrarse luego de la sexta década de la vida. Estudios experimentales en modelos animales y humanos sugirieron la existencia de mecanismos fisiológicos por los cuales los estrógenos podrían ser los responsables de esta protección cardiovascular, y análisis retrospectivos de estudios clínicos mostraron que las mujeres climatéricas que habían consumido terapia hormonal de reemplazo (THR) sufrían menos eventos cardiovasculares. Estas observaciones estimularon la ejecución de numerosos ensayos clínicos prospectivos aleatorizados (algunos de gran envergadura) en mujeres climatéricas, destinados a probar la hipótesis de que la THR podría prevenir eventos cardiovasculares graves en esa población. La hipótesis no pudo probarse, ya que en ninguno de esos ensayos la THR fue efectiva, y en algunos casos incluso fue en ciertos aspectos perjudicial. Existen cuestionamientos de orden metodológico que tienen que ver con el diseño de dichos ensayos prospectivos, fundamentalmente la edad de las pacientes incluidas y el momento del inicio de la THR. Existen también razones biológicas que pueden explicar la mencionada contradicción. Una nueva hipótesis, basada asimismo en observaciones experimentales y clínicas, se orienta hacia la posibilidad de que el inicio de la THR en mujeres más jóvenes y más precozmente luego de la menopausia, podría mostrar diferentes resultados.

During their fertile period women suffer significantly less atherosclerotic cardiovascular disease (particularly myocardial infarction) than men. This benefit progressively disappears after menopause, to equalize after the sixth decade of life. Experimental studies in animal and human models demonstrated the existence of physiological mechanisms suggesting that estrogens could be responsible for this cardiovascular protection, and retrospective analysis of clinical studies showed that post menopausal women who had used hormonal replacement therapy (HRT) suffered less cardiovascular events. These observations stimulated the execution of several prospective, randomized clinical trials (some of them with a large number of patients and prolonged follow-up) in post menopausal women, with the aim of proving the hypothesis that HRT could prevent major cardiovascular events. Such hypothesis could not be demonstrated in any of those studies because HRT was not beneficial, and in several cases it was even deleterious in some aspects. Criticism has arisen over some of the methodological aspects of those prospective trials, basically regarding the age of the included patients and the timing of the beginning of HRT. There are also biological reasons that can explain the contradiction. A new hypothesis, also based on experimental and clinical observations, suggests the possibility that beginning HRT in younger women and earlier after menopause could yield different results.

Update on osteoporosis therapy / Atualização no tratamento da osteoporose

Osteoporosis is a skeletal disorder characterized by compromised bone strength that predisposes a person to increased fracture risk. Fractures are often associated with increased morbidity, higher mortality, loss of function and even psychological consequences. Pharmacotherapeutic interventions (e.g., bisphosphonates, selective estrogen receptor modulators, calcitonin, and teriparatide) in women with postmenopausal osteoporosis provide substantial reduction in fracture risk over and above risk reduction with calcium and vitamin D supplementation alone. The importance of nutritional support along with an appropriate exercise regimen, avoiding smoking and excessive alcohol use is to be emphasized along with the pharmacologic approach to osteoporosis. Despite the effectiveness of therapy with pharmacologic agents, most patients who start therapy do not remain on treatment for more than 1 year.

Osteoporose é uma doença esquelética caracterizada pelo comprometimento da força óssea que predispõe ao aumento do risco de fratura na pessoa. As fraturas são sempre relacionadas com aumento da morbidade, alta mortalidade, perda funcional e mesmo conseqüências psicológicas. Intervenções farmacoterapêuticas (por exemplo, bisfosfonatos, moduladores seletivos dos receptores de estrogênios, calcitonina e teriparatida) na mulher com osteoporose pós-menopausa resultam numa redução substancial do risco de fratura, superior ao risco obtido com suplementação de cálcio e vitamina D somente. A importância do suporte nutricional junto com série de exercícios apropriados, o evitar o tabagismo e uso excessivo de álcool devem ser enfatizados junto com a abordagem farmacológica da osteoporose. Apesar da efetividade da terapia com agentes terapêuticos, a maioria dos pacientes que iniciam tratamento não o mantém por mais de um ano.

Effects of tamoxifen therapy on plasma lipid profile in patients of breast cancer.

AIM: To evaluate the effects of tamoxifen therapy on plasma lipid profile in patients of breast cancer. METHOD: A total of 55 postoperative patients of breast cancer were given tablet tamoxifen 20mg orally daily for 6 months. Estimation of plasma lipid by standard method was carried out in both pre-menopausal and postmenopausal new patients of early stage breast cancer at 0 day, 3rd month and 6th months of therapy. RESULTS: Suggested that in pre-menopausal and postmenopausal patient's TC and LDL-c levels were reduced significantly, whereas, TG, VLDL-c and HDL-c were not altered. Comparison of the effects of tamoxifen in pre-menopausal and postmenopausal patients on lipid profile revealed that fall in TC and LDL-c was significantly higher at both 3 and 6 months in postmenopausal patients. CONCLUSION: The study demonstrates that tamoxifen to favorably alter the markers of cardiovascular risk in both pre-menopausal and postmenopausal patients of breast cancer.

Tamoxifeno e raloxifeno: papel na quimioprevenção do câncer de mama / Tamoxifen and raloxifene: their role in chemoprevention for breast cancer

O Câncer de mama é a neoplasia de maior incidência na mulher brasileira, e já dispomos de meios para sua prevenção primária. A quimioprevenção agora é uma possibilidade real para mulheres consideradas de alto risco, de redução no risco para desenvolver câncer de mama. Os moduladores seletivos dos receptores de estrogênio foram bastante pesquisados por seu potencial efeito antagonista no tecido mamário. O tamoxifeno foi a primeira droga estudada e liberada para quimioprevenção do câncer de mama; no entretanto, surgiu um grande interesse pelo raloxifeno, quando se verificou redução na incidência do câncer de mama, em pacientes que usaram essa droga para tratamento de osteoporose. Os autores compararam essas drogas com base em suas possibilidades terapêuticas, seus efeitos colaterais e seu potencial quimiopreventivo contra o câncer de mama

Indicaciones y contraindicaciones oncológicas del uso de hormonas en la menopausia / Oncologic indications and contra-indications of the hormonal use in menopause

Las expectativas de vida han cambiado el manejo de la menopausia, etapa de la vida en la que la mujer presenta la mayor incidencia de cáncer. La terapia hormonal (TH) tiene en la actualidad indicaciones más acotadas y en particular en las pacientes que ya tuvieron cáncer. Las contraindicaciones oncológicas para el uso de TH son analizadas en relación a tumores hormono dependientes (endometrio y mama), a los con dependencia parcial (ovario y adenocarcinoma de cuello) y a los independientes (cuello,vulva y vagina).El cáncer colorectal, de alta mortalidad, se suponía protegido por TH, pero hoy no se puede confirmar esa observación. El aumento de incidencia y mortalidad del cáncer de mama es concluyente. La alta prevalencia de este tumor invita a ser cautelosos y advertidos en el diagnostico precoz en aquellas poblaciones mas expuestas. La TH combinada y por periodos de mas de la al1.0S demostró un incipiente incremento. Se esta en la búsqueda de hormonas selectivas que no estimulen los receptores en la mama y en el endometrio y que actúen favorablemente sobre otras áreas.

The life expectation has been changeable the manner of menopause handling. At the same time, the women after fifty have the highest incidence of cancer. The hormonal replacement therapy (HT) to date has very few indications for patients with cancer. The oncologic contraindication for HT are analysed in detail, particulary for breast tumour. At the present time, the studies and the metanalysis on HT and breast cancer not showed a quantitative increase on the risk. We are looking for selective hormone with antagonist for endometrium and breast receptors, and effectiveness on the others areas.

Moduladores seletivos do receptor estrogênico e redução do risco de câncer de mama: tamoxifeno e raloxifeno / Selective estrogen receptor modulators and breast cancer risk reduction: tamoxifen and raloxifene

Os moduladores seletivos dos receptores estrogênicos(Serms: selective estrogen receptor modulators) são medicamentos que se ligam aos receptores de estrógeno e atuam como agonistas em determinados tecidos(p. exemplo tecido ósseo) e como antagonistas do estrógeno em outros(útero e mamas). Pelo fato de atuarem como antagonistas estrogênicos na mama, os SERMs têm se mostrado eficazes na redução do risco de câncer de mama positivo para receptores de estrógeno. O uso do tamoxifeno na prevenção do câncer de mama foi avaliado em quatro principais estudos clínicos e demonstrou-se que o tamoxifeno, usado por cinco anos, reduz a incidência de câncer de mama positivo para receptor de estrógeno de forma estatisticamente significante em mulheres com alto risco. O aumento do risco de câncer de endométrio após cinco anos de uso da medicação torna importante a seleção de pacientes onde os benefícios sejam claramente maiores que os eventuais riscos decorrentes da terapia. O cloridrato de raloxifeno é um SERM de segunda geração que se liga com alta afinidade aos receptores estrogênicos e apresenta intensa atividade antiestrogênica no útero e mamas e atividade estogênica no tecido ósseo. No principal estudo realizado com raloxifeno, o More, observou-se redução de risco de 76 por cento, estatiscamente significante, de casos de câncer de mama em mulheres na pós-menopausa com osteoporose, após três anos. Estes resultados confirmaram-se também após quatro anos. Os dados de redução de risco de câncer de mama com raloxifeno, em mulheres na pós-menopausa, abrem uma nova perspectiva à redução do risco de câncer de mama

Quimioprevencion del cancer de mama: ensayos clinicos en la prevencion farmacologica / Chemoprevention of breast cancer: clinical trials in pharmacological prevention

El presente artículo trata sobre los ensayos clínicos presentados en quimioprevención del cáncer mamario. Hasta la fecha las drogas más estudiadas han sido los Moduladores Selectivos de los Receptores de Estrógenos (SERMs). Cuatro estudios aleatorizados de tamoxifeno versus placebo fueron publicados y dos con raloxifeno están en curso. Dos de los estudios con tamoxifeno mostraron una reducción de incidencia de cáncer mamario entre el 30 y el 50%, sin embargo otros dos trabajos no mostraron diferencias estadísticamente significativas. A esta controversia se le suma la incertidumbre sobre el verdadero impacto en la mortalidad que pudiera tener este tipo de terapia preventiva. Se citan además diversos estudios que evaluaron la ingesta de vitaminas y su relación con el desarrollo de tumores mamarios. Sin duda alguna el estudio y el seguimiento de los ensayos clínicos nos permitirán dilucidar qué pacientes requieren una terapia, preventiva del desarrollo de un tipo específico de cáncer, que se encuentra lejos de estar exenta de riesgos.

Hormone replacement therapy and the risk of breast cancer: assessment of therapy acceptance in a cohort of previously treated breast cancer patients

INTRODUCTION: In the postmenopausal period, an average of 25 percent of women will present symptomatic ovarian failure requiring hormonal replacement therapy. Estrogen can relieve vasomotor symptoms. Hormonal replacement therapy is generally not recommended for breast cancer patients due to the potential risk of tumor recurrence. To answer the questions about the safety of hormonal replacement therapy in this subgroup of women, it is necessary to establish the acceptance of treatment. METHODS: Between September 1998 and February 2001, a cohort of 216 breast cancer patients were asked to complete a questionnaire. All patients had completed their treatment and were informed about survival rates after breast cancer and hormonal replacement therapy. RESULTS: Among the 216 patients, 134 (62 percent) would refuse hormonal replacement therapy. A hundred patients were afraid of relapse (74.6 percent). Adjuvant tamoxifen therapy was the only statistically significant variable (70.3 percent versus 29.7 percent p=0.003). Understanding clinical stage (p= 0.045) and type of medical assistance (private versus public , p=0.033) also seemed to influence the decision. Early stage disease (p= 0.22), type of surgical procedure (radical versus conservative, p=0.67), adjuvant chemotherapy (p=0.082) or marital status (p=0.98 ) were not statistically significant in decision making. Several patients submitted to adjuvant chemotherapy (41.6 percent) would accept hormonal replacement therapy under medical supervision, as did most of advanced clinical stage patients (58.3 percent; p=0.022). CONCLUSION: There is a high level of rejection for hormonal replacement therapy among breast cancer patients when current data on tumor cure rates, and potential risks of estrogen use is available. Adverse effects of tamoxifen in the adjuvant setting may be the reason for refusal of hormonal replacement therapy