Review of menopausal hormone therapy with estradiol and progesterone versus other estrogens and progestins.

Objective: The objective of the present document was to review/summarize reported outcomes compared between menopausal hormone therapy (MHT) containing estradiol (E2) versus other estrogens and MHT with progesterone (P4) versus progestins (defined as synthetic progestogens).Methods: PubMed and EMBASE were systematically searched through February 2021 for studies comparing oral E2 versus oral conjugated equine estrogens (CEE) or P4 versus progestins for endometrial outcomes, venous thromboembolism (VTE), cardiovascular outcomes, breast outcomes, cognition, and bone outcomes in postmenopausal women.Results: A total of 74 comparative publications were identified/summarized. Randomized studies suggested that P4 and progestins are likely equally effective in preventing endometrial hyperplasia/cancer when used at adequate doses. E2- versus CEE-based MHT had a similar or possibly better risk profile for VTE and cardiovascular outcomes, and P4- versus progestin-based MHT had a similar or possibly better profile for breast cancer and cardiovascular outcomes. E2 may potentially protect better against age-related cognitive decline and bone fractures versus CEE; P4 was similar or possibly better versus progestins for these outcomes. Limitations are that many studies were observational and some were not adequately powered for the reported outcomes.Conclusions: Evidence suggests a differential effect of MHT containing E2 or P4 and those containing CEE or progestins, with some evidence trending to a potentially better safety profile with E2 and/or P4.

Endometrial safety of low-dose vaginal estrogens in menopausal women: a systematic evidence review.

OBJECTIVE: The aim of the study was to systematically review studies that evaluated endometrial hyperplasia or cancer incidence with unopposed vaginal estrogens. METHODS: PubMed and EMBASE were searched from inception to August 2017 for relevant articles and abstracts. Bibliographies of review articles and abstracts of major women's health medical meetings were examined. Eligible studies (independently reviewed by 4 authors) had to report menopausal vaginal estrogen use and endometrial histology, or incidence of endometrial hyperplasia or cancer. RESULTS: Of 5,593 abstracts from the literature search and 47 articles from other sources, 36 articles and 2 abstracts were eligible, describing 20 randomized controlled studies, 8 interventional studies, and 10 observational studies. Collectively, the studies did not support an increased risk of endometrial hyperplasia or cancer with low-dose vaginal estrogens. Rates of endometrial cancer and hyperplasia were 0.03% and 0.4%, respectively, from 20 randomized controlled trials (2,983 women) of vaginal estrogens. Overall, reports of endometrial hyperplasia were observed with various doses and durations and appeared sporadic (except 1.25 mg conjugated equine estrogens), consistent with endometrial hyperplasia rates in the general population. A Denmark registry study was an exception and may be of limited applicability to the United States. The Women's Health Initiative Observational Study showed no association (1.3 cases/1,000 women-years with vaginal estrogens versus 1.0/1,000 women-years for nonuse). CONCLUSION: This systematic review supports the use of low-dose vaginal estrogens for treating vulvar and vaginal atrophy in menopausal women without a concomitant progestogen. This review does not support increased endometrial hyperplasia or cancer risk with low-dose, unopposed vaginal estrogens; however, longer-term, real-world data are needed.

Using bazedoxifene plus conjugated estrogens for treating postmenopausal women: a comprehensive review.

The objective of this article was to review clinical outcomes reported with the tissue selective estrogen complex containing bazedoxifene (BZA) and conjugated estrogens (CE) in postmenopausal women. PubMed was searched from inception to June 2011 using the key words bazedoxifene and conjugated estrogens. We reviewed six published articles reporting the clinical efficacy and safety outcomes of three different level I evidence, multicenter, blind, randomized, placebo-controlled studies. BZA/CE reduced hot flush frequency and severity, prevented loss of bone mass, and treated vulvar-vaginal atrophy and its symptoms without endometrial stimulation and provided amenorrhea and breast tenderness rates similar to those with placebo. Overall safety was not different from that observed with placebo, and no unexpected findings were reported. The tissue selective estrogen complex composed of BZA/CE is a new progestin-free therapy that alleviates hot flushes and prevents the loss of bone mass in postmenopausal women with endometrial hyperplasia and amenorrhea rates comparable with those of placebo.

SERMs: progress and future perspectives.

Selective estrogen receptor modulators (SERMs) interact with estrogen receptors as agonists or antagonists depending on the target tissue. Currently available SERMs are used to treat and prevent breast cancer and osteoporosis, to treat ovulatory dysfunction in women, and for contraception. Because current therapies do not adequately treat menopausal symptoms, the search continues for the optimal SERM for postmenopausal women, which would relieve hot flushes, treat vaginal atrophy, and prevent fractures, while protecting the endometrium, breast, and cardiovascular system. Future use of SERMs may also include their use in a tissue selective estrogen complex (TSEC), a therapy that combines a SERM with estrogen(s), designed to deliver the efficacy of each component with improved overall tolerability for the treatment of postmenopausal women. The future of SERMs may also include their use in men for the treatment of osteoporosis and various syndromes associated with secondary hypogonadism and possibly prostate cancer. Continued research should allow the full potential of SERMs to be uncovered.

Relaxin increases secretion of tissue inhibitor of matrix metalloproteinase-1 and -2 during uterine and cervical growth and remodeling in the pig.

Remodeling of reproductive organs during pregnancy requires degradation and resynthesis of structural barriers to cell invasion. Matrix metalloproteinases (MMPs) are enzymes that break down components of the extracellular matrix (ECM) and are essential for tissue remodeling processes. Tissue inhibitors of metalloproteinases (TIMPs) are important regulators of MMP activity. In the pig, relaxin stimulates growth and remodeling of the uterus and cervix during pregnancy, effects that include the ability to alter elements of the ECM. Therefore, the objective of this study was to determine whether relaxin alters the production and/or activity of TIMP-1 and TIMP-2 in the porcine uterus or cervix. The growth-promoting effects of relaxin were elicited by administering relaxin to prepubertal gilts every 6 h for 54 h. Expression of TIMP-1 and TIMP-2 was characterized by immunoblotting. Total enzyme activity was measured using an MMP-specific fluorescent substrate assay. TIMP-1 and TIMP-2 proteins were present in the uterus and cervix of control and relaxin-treated pigs, and both proteins were increased by relaxin in the uterine flushes and tissues (P < 0.05). Inhibitor activity in uterine tissue extracts and uterine flushes from relaxin-treated animals was greater than that in controls; however, this activity was restricted to inhibition of MMP-2. In the uterine cervix, relaxin enhanced expression of TIMP-1 and TIMP-2 (P < 0.05), whereas expression of both TIMP proteins was similar in the vaginal cervix of control and relaxin-treated animals. Likewise, inhibitor activity against MMP-2 in the uterine cervix was enhanced in response to relaxin (P < 0.05). In contrast, inhibitor activity was attenuated in extracts from the vaginal cervix (P < 0.05). This study highlights the complex nature of MMP/TIMP regulation during reproductive tissue growth and suggests that TIMP-1 and TIMP-2 may be involved in other aspects of the growth process. These data support a role for relaxin in regulating the activity of TIMPs during growth and remodeling of reproductive connective tissue.