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 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Indications and complications of estrogen replacement therapy are discussed in this edited transcription of a conference held at the UCLA School of Medicine. Although many of the symptoms of loss of ovarian function can be corrected by estrogen replacement therapy, several potentially harmful side effects are associated with the administration of estrogen. Hot flashes, the most common menopausal symptom for which women seek treatment, may continue over extended periods of time and the loss of ovarian feedback signals. Several types of evidence indicate that hot flashes are centrally rather than peripherally mediated disturbances, and it now appears that the hypothalamic factors which stimulate pulsatile release of luteinizing hormone play an integral role in initiation of hot flashes. The fact that the extent of estrogen deficiency differs among postmenopausal women may explain why all women do not have hot flashes. The effects of body size on estrogen production and plasma protein binding appear to be significant variables modulating the extent of estrogen deficiency and hypothalamic function. Other studies suggest that calcitonin and gonadal steroids are linked in the pathogenesis and treatment of osteoporosis, but the mechanism of action of estrogen replacement therapy in the treatment of osteoporosis has not been elucidated. Most investigations have failed to show the presence of estrogen receptors in bone. It is likely that the term osteoporosis includes heterogeneous skeletal disorders and that both sex hormones and calcemic hormones are important in pathogenesis. Further research is required on the possible effect of estrogen replacement therapy in decreasing relative risk of arteriosclerotic heart disease. Vaginal atrophy is an accepted indication for estrogen replacement, but its use for skin indications should not be recommended until a beneficial cosmetic effect is shown. Complications of estrogen replacement include endometrial cancer, breast cancer, hypertension, hyperlipidemia, and gallbladder disease, the latter 3 apparently resulting from hepatic action of estrogen replacement therapy. Because of the enhanced hepatic action of orally administered estrogen, other routes of administration are being explored. Additional research is needed to define the risk-benefit ratio of estrogen replacement therapy.
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PMID:Estrogen replacement therapy: indications and complications. 682 55

The use of estrogen replacement therapy in postmenopausal women is under close scrutiny. The indications and side effects of replacement therapy are reviewed, and recommendations regarding its use are made. Hot flashes, atrophy of the vaginal epithelium, and prevention of osteoporosis have been established as indications for estrogen replacement therapy. Prevention of cardiovascular disease, aging changes of skin, and the occurrence of mental illness have also been suggested as indications, but beneficial effects of estrogen replacement therapy for these problems have not been clearly established. Studies have shown that side effects of estrogen replacement therapy include endometrial cancer, hypertension, gallbladder disease, and angina pectoris. Breast cancer may also be a risk factor, but a consensus of opinion has not been established. Pulmonary embolism, cerebral vascular accident, or myocardial infarction has not been associated with estrogen replacement therapy. The use of progesterone with estrogen replacement therapy has been shown to reduce the occurrence rate of endometrial carcinoma, but it does not prevent all the actions of estrogen. Oral administration of estrogen is the preferred route despite misgivings about portal absorption and liver metabolism. Further studies must examine this question. Various agents have been shown to be effective in treating some climacteric symptoms. These include progesterone for hot flashes and calcium for the prevention of osteoporosis. Other agents may also be effective but have not been tested critically.
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PMID:Estrogen replacement therapy. 702 79

Entry into menopause is associated with a severe diminution of ovarian estrogen and progesterone secretion and a reduction of circulating androgens, although, in the presence of ovaries, a degree of testosterone secretion persists. Menopause is associated to a varying degree and severity, with hot flashes--a disorder of central thermoregulation--progressive sex tissue atrophy, and accelerated bone mineral loss that eventually leads to a substantial prevalence of osteoporosis, with spine, hip, and radial fractures, particularly in thin, inactive smokers with low calcium intake. Treatment with estrogens eliminates hot flashes and sex tissue atrophy and prevents osteoporosis. Unfortunately, oral estrogen therapy results in overstimulation of the liver, producing secreted proteins and an increased risk of endometrial carcinoma and gallbladder disease. The addition of a progestogen will diminish the risk of endometrial carcinoma, presumably by reducing estrogen-receptor concentration and increasing estradiol dehydrogenase activity but will usually result in vaginal bleeding in women with uteri. The use of estrogen therapy with or without a progestin should be an informed joint decision of physician and patient that must be reevaluated regularly as new information becomes available.
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PMID:Menopausal endocrinology and management. 704 70

As more women are living longer, there is an increasing need for women to discuss hormone replacement therapy (HRT) with their physicians. This task is complicated by areas of scientific uncertainty and evolving data concerning the risks and benefits of HRT. Benefits of HRT that are supported by strong scientific evidence include relief from menopausal symptoms such as hot flashes, prevention of osteoporosis, cardioprotective effects, relief of urogenital atrophy, and decreased urinary incontinence. Benefits supported by observational evidence include improvement of emotional lability and depression, improved sense of well-being in patients with rheumatoid arthritis, increased dermal and total skin thickness, improved verbal memory skills, and decreased risk of colon cancer. Risks to consider include a possible increase in the incidence of breast cancer and an increase in endometrial cancer in women who have an intact uterus and do not receive a progestin. Women in various risk groups, such as those at risk for coronary artery disease, osteoporosis, or breast cancer, must consider the risk-to-benefit ratio for their own individual circumstances.
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PMID:Current concepts in postmenopausal hormone replacement therapy. 869 Nov 83

Estrogens play a central role in reproductive physiology. The cellular effects of estrogens are mediated by binding to nuclear receptors (ER) which activate transcription of genes involved in cellular growth control. At least two such receptors, designated ERalpha and ERbeta, mediate these effects in conjunction with a number of coactivators. These receptors can directly interact with other members of the steroid receptor superfamily. A complex cross-talk exists between the estrogen-signaling pathways and the downstream signaling events initiated by growth factors, such as epidermal growth factor and insulin-like growth factors. Estrogens are also a causative factor in the pathogenesis of a variety of neoplastic and non-neoplastic diseases, including breast cancer, endometrial cancer, endometriosis, and uterine fibroids, among others. Antiestrogens, such as tamoxifen, are widely used for the treatment of breast cancer. Tamoxifen produces objective tumor shrinkage in advanced breast cancer, reduces the risk of relapse in women treated for invasive breast cancer, and prevents breast cancer in high-risk women. Although, initially developed as an antiestrogen, tamoxifen can also prevent postmenopausal osteoporosis as well as reduce cholesterol, due to its estrogen-agonist effects. Its estrogen-agonist activity, however, can lead to significant side-effects such as endometrial cancer and thromboembolic phenomena. This has led to the concept of "ideal" selective estrogen receptor modulators (SERMs), drugs that would have the desired, tissue selective, estrogen-agonist or -antagonist effects. Raloxifene is a SERM which has the desirable mixed agonist/antagonist effects of tamoxifen but does not cause uterine stimulation. "Pure" antiestrogens may provide very potent estrogen-antagonist drugs, but are likely to be devoid of beneficial effects on bone and lipids. Future drug development efforts should focus on developing superior SERMs that have a greater efficacy against ER-positive tumors and do not cause hot flashes or thromboembolism, and explore combination strategies to simultaneously target hormone-dependent as well as hormone-independent breast cancer.
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PMID:Antiestrogens--tamoxifen, SERMs and beyond. 1066 80

Age is the most important risk factor for the development of breast cancer. The risk of breast cancer continues to increase in American women until the age of 80 years. A family history of breast cancer helps identify those who possibly have the highest risk of developing breast cancer; however, most women who develop breast cancer do not have a first-degree relative with a history of breast cancer. Currently, the Gail model is a commonly used model to identify risk, and this model has now been validated in several populations of women undergoing screening for breast cancer. The first large-scale breast cancer prevention trial investigating the preventive effects of tamoxifen has demonstrated a decrease in the development of breast cancer by almost 50% in the women in the tamoxifen treatment arm as compared with those receiving placebo. The NSABP P-1 trial was the largest of the three tamoxifen breast cancer prevention trials and had the greatest power to detect a difference between the two treatment groups in breast cancer events. This trial also included the largest percentage of postmenopausal women. It is unclear why the Italian and Royal Marsden Hospital trials had negative results regarding the preventive effects of tamoxifen. These two trials were strikingly different from the NSABP P-1 trial, however, and they included a different population of women. The issues surrounding the use of HRT for treatment of hot flashes in the Italian and Royal Marsden Hospital trials adds to the controversy concerning the negative results of these trials. The new SERM, raloxifene, has shown promise in preliminary studies as a preventive agent for breast cancer. The STAR trial will open soon and will evaluate the efficacy of raloxifene in preventing breast cancer in a prospective fashion, comparing its efficacy with tamoxifen treatment. Other endpoints will evaluate side effects such as menopausal symptoms, endometrial cancer, thromboembolic events, and benefits regarding serum lipids and incidence of osteoporotic bone fractures. The development of SERMs results from an understanding of novel mechanisms of ER modulation and allows targeting for favorable effects in specific tissues. The challenge is to develop an ideal SERM that is effective in preventing breast cancer and does not increase the risk of endometrial cancer, while providing beneficial estrogenic effects on serum lipids and bone mineral density changes. Estrogen receptor-mediated intracellular processes are complex. There are at least two different types of estrogen receptors. The alpha receptors predominate in the breast and uterus, and the beta receptors predominate in the bone and blood vessels. Many proteins also interact with these receptors as co-activators or co-repressors. Transcription-activating factors modulate the effects of estrogen on its target genes. Future prevention strategies may use a combined targeted approach to inhibit ER-mediated cancer progression pathways. The retinoids are under investigation in prevention studies for a multitude of cancers, because they have been shown to inhibit cellular proliferation and to induce cellular differentiation. The retinoid 4HPR was selected for use in breast cancer prevention studies because of its low toxicity profile and prevention efficacy in preclinical studies. It is now being used in combination with tamoxifin in a phase II breast cancer prevention trial. Multiple surrogate endpoint biomarkers are being measured before and after treatment, including measurement of serum IGF-I levels. Future directions in breast cancer prevention include the development of more potent hormonal therapies that completely inhibit ER-mediated cancer progression and, ultimately, multitargeted therapies involving agents that work synergistically.
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PMID:Chemoprevention of breast cancer in the older patient. 1068 75

Postmenopausal women have sought nonestrogen alternatives to hormone replacement in order to avoid possible risks and side effects of the therapy. Selective estrogen receptor modulators have been developed to tailor therapy to a specific risk/benefit profile that will best fit the patient. More women have looked to phytoestrogens, such as the isoflavones found in the soy plant, to tailor their menopausal therapy in a "natural" way. This review examines the evidence regarding the risks and benefits of isoflavones as hormone replacement therapy. Controlled trials have shown a reduction in postmenopausal hot flashes when subjects' diets were supplemented with soy. There is less evidence for a benefit in vaginal dryness symptoms. Furthermore, dietary supplementation also appears to lower total and low-density lipoprotein cholesterol in hypercholesterolemic subjects. A synthetic isoflavone, ipriflavone, has been shown in controlled trials to prevent postmenopausal bone loss, though there is much less evidence that soy isoflavones will accomplish this goal. Finally, although unopposed estrogen replacement may promote breast and endometrial cancer, there is no evidence that phytoestrogens will do the same. In contrast, great interest has been taken in the potential cancer-protective effects of phytoestrogens, though prospective evidence in postmenopausal women is not available. Although data regarding the use of isoflavone extracts are incomplete, dietary supplementation with soy foods appears to be a safe and possibly beneficial option for postmenopausal women.
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PMID:Phytoestrogens as hormone replacement therapy: an evidence-based approach. 1107 39

Tamoxifen, a selective estrogen receptor modulator (SERM), is the treatment of choice for all stages of hormone-responsive breast cancer and has been shown to prevent breast cancer in high-risk women. Despite acting as an antiestrogen on the breast, tamoxifen has partial estrogenic effects on other target tissues. These partial estrogen agonistic actions produce beneficial effects on bones and the lipid profile in postmenopausal women. However, tamoxifen is associated with an increase in endometrial cancer. Additionally, its antiestrogenic effects in the central nervous system result in hot flashes in postmenopausal women. Raloxifene is another SERM approved for the prevention of osteoporosis in postmenopausal women. Like tamoxifen, raloxifene appears to prevent breast cancer in high-risk women and has not, to date, been noted to increase the incidence of endometrial cancer. The Study of Tamoxifen and Raloxifene will compare the effects of the two agents on breast cancer prevention and endometrial cancer risk. A number of new agents are being developed for breast cancer treatment and prevention and osteoporosis prevention. These include other SERMs, selective estrogen receptor downregulators (SERDs), and aromatase inhibitors. It is hoped that one of these new agents will be the ideal agent, acting as an antiestrogen on breast and endometrium while having estrogenic effects on bones, the lipid profile, and the central nervous system. Semin Oncol 28:260-273.
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PMID:Tamoxifen to raloxifene and beyond. 1140 36

Tamoxifen (Nolvadex), a selective estrogen-receptor modulator, or SERM, is currently the endocrine therapy of choice for all stages of hormone-responsive breast cancer. Only tamoxifen has been approved by the US Food and Drug Administration to reduce the incidence of breast cancer in high-risk women. Despite tamoxifen's antiestrogenic effects in breast tissue, it exhibits paradoxical estrogenic effects in other tissues in the body. These effects result in the maintenance of bone mineral density, but a three- to fourfold increase in endometrial cancer in postmenopausal women. Additionally, tamoxifen can result in troublesome hot flashes and serious thromboembolic events. For this reason, current research is focusing on new agents that may maintain the beneficial effects of tamoxifen while reducing its adverse effects. Raloxifene (Evista) is another SERM, approved for the prevention of osteoporosis in postmenopausal women and now being compared with tamoxifen in an ongoing breast cancer prevention trial. Like tamoxifen, raloxifene is associated with hot flashes and thromboembolic events, but its association with the risk of endometrial cancer is unknown. A number of new SERMs are in preclinical or clinical development in an attempt to improve upon the safety profile of tamoxifen. Additionally, selective aromatase inhibitors are being examined in the early breast cancer setting.
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PMID:Selective estrogen-receptor modulators in 2001. 1158 65

Hormone replacement therapy (HRT) with estrogens (in non-hysterectomized women with estrogens and progestins) during the peri- and postmenopausal period has been widely applied for many years. On the basis of new data, HRT is currently being critically reviewed. HRT administered for up to 5 years to treat climacteric hot flashes, mood changes and sleep disturbances continues to be advocated and is largely safe. When HRT is used for longer periods, as required for the prevention of osteoporosis, a possible increase in the relative risk for breast cancer must be considered. Correctly applied in combination with an adequate dose of progestins, HRT can avoid an increase in the endometrial cancer risk. HRT is no longer recommended for secondary prevention of cardiovascular disease, and its use in primary prevention has not been convincingly demonstrated. The hoped-for efficacy of HRT in the prevention of Alzheimer's disease has not been confirmed by the data. Selective estrogen receptor modulators (e.g. Raloxifene) and biphosphonates are efficacious drugs for the prevention and treatment of osteoporosis. For women at risk of developing cardiovascular disease, changes in lifestyle, lipid-lowering drugs (statins), blood pressure control, use of acetylsalicylic acid, among others, have well-documented efficacy in primary and secondary prevention.
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PMID:[Hormone replacement therapy in peri- and postmenopause. Routine use is not indicated]. 1192 48


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