Bazedoxifene/conjugated estrogens for managing the burden of estrogen deficiency symptoms

Management of perimenopausal and menopausal symptoms

Most women worldwide experience menopausal symptoms during the menopause transition or postmenopause. Vasomotor symptoms are most pronounced during the first four to seven years but can persist for more than a decade, and genitourinary symptoms tend to be progressive. Although the hallmark symptoms are hot flashes, night sweats, disrupted sleep, and genitourinary discomfort, other common symptoms and conditions are mood fluctuations, cognitive changes, low sexual desire, bone loss, increase in abdominal fat, and adverse changes in metabolic health. These symptoms and signs can occur in any combination or sequence, and the link to menopause may even be elusive. Estrogen based hormonal therapies are the most effective treatments for many of the symptoms and, in the absence of contraindications to treatment, have a generally favorable benefit:risk ratio for women below age 60 and within 10 years of the onset of menopause. Non-hormonal treatment options are also available. Although a symptom driven treatment approach with individualized decision making can improve health and quality of life for midlife women, menopausal symptoms remain substantially undertreated by healthcare providers.

Mechanistic Effects of Estrogens on Breast Cancer

PURPOSE

Current concepts regarding estrogen and its mechanistic effects on breast cancer in women are evolving. This article reviews studies that address estrogen-mediated breast cancer development, the prevalence of occult tumors at autopsy, and the natural history of breast cancer as predicted by a newly developed tumor kinetic model.

METHODS

This article reviews previously published studies from the authors and articles pertinent to the data presented.

RESULTS

We discuss the concepts of adaptive hypersensitivity that develops in response to long-term deprivation of estrogen and results in both increased cell proliferation and apoptosis. The effects of menopausal hormonal therapy on breast cancer in postmenopausal women are interpreted based on the tumor kinetic model. Studies of the administration of a tissue selective estrogen complex in vitro, in vivo, and in patients are described. We review the various clinical studies of breast cancer prevention with selective estrogen receptor modulators and aromatase inhibitors. Finally, the effects of the underlying risk of breast cancer on the effects of menopausal hormone therapy are outlined.

DISCUSSION

The overall intent of this review is to present data supporting recent concepts, discuss pertinent literature, and critically examine areas of controversy.

Hormonal management of menopausal symptoms in women with a history of gynecologic malignancy

OBJECTIVE

The aim of the study was to review the role of hormone therapy in menopausal patients with breast cancer and gynecologic malignancies.

METHODS

We searched MEDLINE (via PubMed) using a combination of keywords and database-specific subject headings for the following concepts: menopause, hormone therapy, and cancer. Editorials, letters, case reports, and comments were excluded, as were non-English articles. Additional references were identified by hand-searching bibliographies of included articles. The searches yielded a total of 1,484 citations. All citations were imported into EndNote X9, where they were screened by the authors.

RESULTS

In breast cancer survivors, systemic hormone therapy is not recommended, whereas local low-dose estrogen therapy may be considered after discussion with the patient's oncologist. Among endometrial cancer survivors, hormone therapy is considered safe in low-risk cancers but should be avoided in high-risk subtypes. For survivors of epithelial ovarian cancer and cervical cancer, hormone therapy can be considered, but should be avoided in women with estrogen-sensitive histologic subtypes.

CONCLUSIONS

The risks of hormone therapy should be assessed on an individual basis, with consideration of age, type of hormone therapy, dose, duration of use, regimen, route, and prior exposure. Systemic hormone therapy is not recommended in breast cancer survivors, whereas vaginal low-dose estrogen appears safe. Hormone therapy may be used by endometrial, cervical, and ovarian cancer survivors with low-risk, non-estrogen-receptor-positive subtypes. Video Summary: http://links.lww.com/MENO/A516.

Effect of a tissue selective estrogen complex on breast cancer: Role of unique properties of conjugated equine estrogen

The Women's Health Initiative studies reported that the menopausal hormone therapy (MHT) regimen containing conjugated equine estrogen (CEE) and medroxyprogesterone acetate increased, whereas CEE alone reduced breast cancer incidence. These observations suggest the possibility that CEE might exert unique actions on breast and also suggest the need to eliminate the progestogen from MHT regimens. A MHT regimen called a tissue selective estrogen complex (TSEC), containing CEE plus bazedoxifene (BZA), to avoid the need for a progestogen, was developed and FDA approved. Our study addressed two questions regarding this TSEC: (i) whether CEE exert effects on breast cancer which differ from those of estradiol (E2 ) and (ii) whether BZA antagonize the effects of E2 and CEE on breast cancer? Two rodent models (NMU and ACI) were used to compare the effect of CEE with E2 on mammary tumor formation, proliferation and apoptosis. In both the NMU and ACI models, E2 significantly increased tumor incidence and multiplicity whereas in striking contrast CEE did not, even though the estrogenic effects of CEE and E2 on uterine weight were identical. Mechanistically E2 blocked whereas CEE stimulated apoptosis (cleaved caspase-3) in ACI animals and only E2 stimulated proliferation (Ki67). BZA exerted highly potent anti-estrogenic effects on tumors by completely blocking palpable tumor formation. These data suggest that the CEE/BZA TSEC may be a safer, breast-antagonistic, MHT agent for women and might have potential to prevent breast cancer while relieving menopausal symptoms.

The 2017 hormone therapy position statement of The North American Menopause Society

The 2017 Hormone Therapy Position Statement of The North American Menopause Society (NAMS) updates the 2012 Hormone Therapy Position Statement of The North American Menopause Society and identifies future research needs. An Advisory Panel of clinicians and researchers expert in the field of women's health and menopause was recruited by NAMS to review the 2012 Position Statement, evaluate new literature, assess the evidence, and reach consensus on recommendations, using the level of evidence to identify the strength of recommendations and the quality of the evidence. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees.Hormone therapy (HT) remains the most effective treatment for vasomotor symptoms (VMS) and the genitourinary syndrome of menopause (GSM) and has been shown to prevent bone loss and fracture. The risks of HT differ depending on type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. Treatment should be individualized to identify the most appropriate HT type, dose, formulation, route of administration, and duration of use, using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of the benefits and risks of continuing or discontinuing HT.For women aged younger than 60 years or who are within 10 years of menopause onset and have no contraindications, the benefit-risk ratio is most favorable for treatment of bothersome VMS and for those at elevated risk for bone loss or fracture. For women who initiate HT more than 10 or 20 years from menopause onset or are aged 60 years or older, the benefit-risk ratio appears less favorable because of the greater absolute risks of coronary heart disease, stroke, venous thromboembolism, and dementia. Longer durations of therapy should be for documented indications such as persistent VMS or bone loss, with shared decision making and periodic reevaluation. For bothersome GSM symptoms not relieved with over-the-counter therapies and without indications for use of systemic HT, low-dose vaginal estrogen therapy or other therapies are recommended.This NAMS position statement has been endorsed by Academy of Women's Health, American Association of Clinical Endocrinologists, American Association of Nurse Practitioners, American Medical Women's Association, American Society for Reproductive Medicine, Asociación Mexicana para el Estudio del Climaterio, Association of Reproductive Health Professionals, Australasian Menopause Society, Chinese Menopause Society, Colegio Mexicano de Especialistas en Ginecologia y Obstetricia, Czech Menopause and Andropause Society, Dominican Menopause Society, European Menopause and Andropause Society, German Menopause Society, Groupe d'études de la ménopause et du vieillissement Hormonal, HealthyWomen, Indian Menopause Society, International Menopause Society, International Osteoporosis Foundation, International Society for the Study of Women's Sexual Health, Israeli Menopause Society, Japan Society of Menopause and Women's Health, Korean Society of Menopause, Menopause Research Society of Singapore, National Association of Nurse Practitioners in Women's Health, SOBRAC and FEBRASGO, SIGMA Canadian Menopause Society, Società Italiana della Menopausa, Society of Obstetricians and Gynaecologists of Canada, South African Menopause Society, Taiwanese Menopause Society, and the Thai Menopause Society. The American College of Obstetricians and Gynecologists supports the value of this clinical document as an educational tool, June 2017. The British Menopause Society supports this Position Statement.

Managing Menopausal Symptoms and Associated Clinical Issues in Breast Cancer Survivors

OBJECTIVE

Review evidence to guide management of menopausal signs and symptoms in women after breast cancer and make recommendations accordingly.

EVIDENCE

Randomized controlled clinical trials, observational studies, evidence-based guidelines, and expert opinion from professional societies.

BACKGROUND

Symptoms and clinical problems associated with estrogen depletion-sleep disorders, vulvovaginal atrophy (VVA), vasomotor symptoms (VMS), mood changes, depressive symptoms, cardiovascular disease, osteopenia, and osteoporosis-confront the estimated 9.3 million breast cancer survivors globally.

RECOMMENDATIONS

Following breast cancer, women should not generally be treated with menopausal hormone therapy or tibolone but should optimize lifestyle. Women with moderate to severe symptoms may benefit from mind-brain behavior or nonhormone, pharmacologic therapy. The selective serotonin/noradrenaline reuptake inhibitors and gabapentenoid agents improve VMS and quality of life. For osteoporosis, nonhormonal agents are available. Treatment of VVA remains an area of unmet need. Low-dose vaginal estrogen is absorbed in small amounts with blood levels remaining within the normal postmenopausal range but could potentially stimulate occult breast cancer cells, and although poorly studied, is not generally advised, particularly for those on aromatase inhibitors. Intravaginal dehydroepiandrosterone and oral ospemiphene have been approved to treat dyspareunia, but safety after breast cancer has not been established. Vaginal laser therapy is being used for VVA but efficacy from sham-controlled studies is lacking. Therapies undergoing development include lasofoxifene, neurokinin B inhibitors, stellate ganglion blockade, vaginal testosterone, and estetrol.

CONCLUSIONS

Nonhormone options and therapies are available for treatment of estrogen depletion symptoms and clinical problems after a diagnosis of breast cancer. Individualization of treatment is essential.

Independent Contributions of Nocturnal Hot Flashes and Sleep Disturbance to Depression in Estrogen-Deprived Women

CONTEXT

Women are at increased risk for mood disturbance during the menopause transition. Hot flashes (HFs), sleep disruption, and fluctuating estradiol levels correlate with menopause-associated depression but co-occur, making cause and effect relationships difficult to disentangle.

OBJECTIVE

Using a GnRH agonist (GnRHa) experimental model, we investigated whether depressive symptoms are associated with HFs and/or are explained by concomitant sleep fragmentation in the absence of estradiol fluctuation.

DESIGN AND INTERVENTION

Depressive symptoms, objective polysomnographic sleep parameters, subjective sleep quality, serum estradiol, and HFs were assessed before and 4 weeks after open-label depot GnRHa (leuprolide 3.75-mg) administration.

SETTING

Academic medical center.

PARTICIPANTS

Twenty-nine healthy nondepressed premenopausal volunteers (mean age, 27.3 years).

RESULTS

Serum estradiol was rapidly and uniformly suppressed. HFs developed in 69% of the subjects. On univariate analysis, worsening of mood was predicted by increases in time in light sleep (stage N1), number of transitions to wake, non-REM arousals, subjective sleep quality, and reductions in perceived sleep efficiency (all P < .045), as well as the number of nighttime (P = .006), but not daytime (P = .28), HFs reported. In adjusted models, the number of nighttime HFs reported, increases in non-REM arousals, time in stage N1, transitions to wake, and reduced sleep quality remained significant predictors of mood deterioration (P ≤ .05).

CONCLUSIONS

Depressive symptoms emerged after estradiol withdrawal in association with objectively and subjectively measured sleep disturbance and the number of nighttime, but not daytime, HFs reported. Results suggest that sleep disruption and perceived nighttime HFs both contribute to vulnerability to menopause-associated depressive symptoms in hypoestrogenic women.

Postmenopausal osteoporosis

Osteoporosis is a metabolic bone disorder that is characterized by low bone mass and micro-architectural deterioration of bone tissue. Fractures of the proximal femur, the vertebrae and the distal radius are the most frequent osteoporotic fractures, although most fractures in the elderly are probably at least partly related to bone fragility. The incidence of fractures varies greatly by country, but on average up to 50% of women >50 years of age are at risk of fractures. Fractures severely affect the quality of life of an individual and are becoming a major public health problem owing to the ageing population. Postmenopausal osteoporosis, resulting from oestrogen deficiency, is the most common type of osteoporosis. Oestrogen deficiency results in an increase in bone turnover owing to effects on all types of bone cells. The imbalance in bone formation and resorption has effects on trabecular bone (loss of connectivity) and cortical bone (cortical thinning and porosity). Osteoporosis is diagnosed using bone density measurements of the lumbar spine and proximal femur. Preventive strategies to improve bone health include diet, exercise and abstaining from smoking. Fractures may be prevented by reducing falls in high-risk populations. Several drugs are licensed to reduce fracture risk by slowing down bone resorption (such as bisphosphonates and denosumab) or by stimulating bone formation (such as teriparatide). Improved understanding of the cellular basis for osteoporosis has resulted in new drugs targeted to key pathways, which are under development.

Update on menopausal hormone therapy

PURPOSE OF REVIEW

Menopause management has undergone an eventful journey over the past decade; some dogmas got refuted, some new hypotheses took life, and the review is timely and relevant to the practice of clinical medicine in 2015.

RECENT FINDINGS

The field stepped out of an era of absolutes into times of patient centeredness and an individualized perspective.

SUMMARY

The onus now is to tailor management to address patient's needs while keeping in perspective individualized symptom burden and risks that may be unique to each aging woman.

The Dual Estrogen Receptor α Inhibitory Effects of the Tissue-Selective Estrogen Complex for Endometrial and Breast Safety

The conjugated estrogen /: bazedoxifene tissue-selective estrogen complex (TSEC) is designed to minimize the undesirable effects of estrogen in the uterus and breast tissues and to allow the beneficial effects of estrogen in other estrogen-target tissues, such as the bone and brain. However, the molecular mechanism underlying endometrial and breast safety during TSEC use is not fully understood. Estrogen receptor α (ERα)-estrogen response element (ERE)-DNA pull-down assays using HeLa nuclear extracts followed by mass spectrometry-immunoblotting analyses revealed that, upon TSEC treatment, ERα interacted with transcriptional repressors rather than coactivators. Therefore, the TSEC-mediated recruitment of transcriptional repressors suppresses ERα-mediated transcription in the breast and uterus. In addition, TSEC treatment also degraded ERα protein in uterine tissue and breast cancer cells, but not in bone cells. Interestingly, ERα-ERE-DNA pull-down assays also revealed that, upon TSEC treatment, ERα interacted with the F-box protein 45 (FBXO45) E3 ubiquitin ligase. The loss-of- and gain-of-FBXO45 function analyses indicated that FBXO45 is involved in TSEC-mediated degradation of the ERα protein in endometrial and breast cells. In preclinical studies, these synergistic effects of TSEC on ERα inhibition also suppressed the estrogen-dependent progression of endometriosis. Therefore, the endometrial and breast safety effects of TSEC are associated with synergy between the selective recruitment of transcriptional repressors to ERα and FBXO45-mediated degradation of the ERα protein.

Short-term and long-term effects of osteoporosis therapies

Progress continues to be made in the development of therapeutics for fracture prevention. Bisphosphonates are now available orally and intravenously, often as inexpensive generics, and remain the most widely used interventions for osteoporosis. The major safety concern associated with the use of bisphosphonates is the development of femoral shaft stress fractures and, although rare, this adverse event affords the principal rationale for restricting bisphosphonate therapy to those individuals with femoral T-scores <-2.5, and for providing drug holidays in those individuals requiring therapy for >5 years. Newer antiresorptive therapies, in the form of denosumab and cathepsin K inhibitors, might increase efficacy and possibly circumvent some of the safety concerns associated with bisphosphonate use (for example, gastrointestinal and renal complications). The combination of teriparatide with antiresorptives markedly increases effects on BMD; new anabolic agents are also very promising in this regard. However, whether or not these changes in BMD translate into improved efficacy of fracture prevention remains to be determined. Vitamin D is important for the prevention of osteomalacia, but does not influence BMD or fracture risk in patients not deficient in vitamin D. The balance of risks and benefits of calcium supplementation is contentious, but patients should be encouraged to adhere to a balanced diet aimed at maintaining a healthy body weight. Consideration of a patient's risk of falling, and its mitigation, are also important. In this Review, I summarize the short-term and long-term effects of osteoporosis therapies.

The Tissue-Selective Estrogen Complex: A Review of Current Evidence

The tissue-selective estrogen complex (TSEC) has recently entered the market for the treatment of postmenopausal osteoporosis, and is particularly targeted to women with significant vasomotor symptoms. This review appraises the evidence behind the only approved TSEC to-date, a combination of bazedoxifene and conjugated estrogens, with regards to its efficacy and relevant safety concerns. The majority of evidence that has led to its approval is derived from the SMART study. This large phase III trial with several substudies was aimed at discerning the effects of the TSEC on various estrogen-responsive tissues in comparison to raloxifene and placebo. Overall, the evidence thus far suggests a superior improvement in lumbar bone mineral density of 1.01% ± 0.28% as well as decrease in the frequency of hot flushes. Regarding safety concerns, endometrial thickness did not change over the treatment course, and investigators also identified a modest reduction in breast density. While there was no difference in rates of venous thromboembolism between treatment and placebo groups in a 2-year follow-up period, the effects of the drug on coagulation profiles are similar to those seen with hormone replacement therapy. Thus, the drug's effects on venous thromboembolism risk over a longer treatment course remain unclear. In conclusion, the actual efficacy of the TSEC for postmenopausal osteoporosis remains as yet undefined, given the lack of fracture prevention data. The evidence thus far does seem to suggest a beneficial effect on vasomotor symptoms and a generally favorable side effect profile. However, it should be noted that only one study has addressed this question thus far, and so the repeatability of the findings is still in question.

Efficacy, effectiveness and side effects of medications used to prevent fractures

There is an increasing number of effective therapies for fracture prevention in adults at risk of osteoporosis. However, shortcomings in the evidence underpinning our management of osteoporosis still exist. Evidence of antifracture efficacy in the groups of patients who most commonly use calcium and vitamin D supplements is lacking, the safety of calcium supplements is in doubt, and the safety and efficacy of high doses of vitamin D give cause for concern. Alendronate, risedronate, zoledronate and denosumab have been shown to prevent spine, nonspine and hip fractures; in addition, teriparatide and strontium ranelate prevent both spine and nonspine fractures, and raloxifene and ibandronate prevent spine fractures. However, most trials provide little information regarding long-term efficacy or safety. A particular concern at present is the possibility that oral bisphosphonates might cause atypical femoral fractures. Observational data suggest that the incidence of this type of fracture increases steeply with duration of bisphosphonate use, resulting in concern that the benefit-risk balance may become negative in the long term, particularly in patients in whom the osteoporotic fracture risk is not high. Therefore, reappraisal of ongoing use of bisphosphonates after about 5 years is endorsed by expert consensus, and 'drug holidays' should be considered at this time. Further studies are needed to guide clinical practice in this area.

Selective estrogen receptor modulators (SERMs): a review of clinical data

SERMs represent a diverse group of molecules with varying levels of estrogenic agonist and antagonist activity in target tissues. SERMs have a long regulatory approval history and have been studied for a variety of therapeutic indications. The clinical effects of SERMs have been evaluated in a large number of phase 3 clinical trials. Many of the available SERMs have proved to be effective as chemo-preventive agents and treatments for breast cancer and a number are useful for the prevention and treatment of osteoporosis. The endometrial effect of SERMs has been a key differentiator in clinical practice and a major hurdle for regulatory approval. The effect of SERMs in the vagina also represents a major distinction among different SERMs. This review summarized key clinical finding of SERMs in different target tissues.