Estrogen-progestagen menopausal hormone therapy and breast cancer: does delay from menopause onset to treatment initiation influence risks?

The WHO claims estrogens are 'carcinogenic': is this true?

Estrogens are in the list of carcinogenic chemicals from the World Health Organization (WHO). However, estrogens require additional factors such as stromal factors or progestogens to increase the ratio of proliferation/apoptosis for initiation of replication errors and consequent mutations to occur. These mutations require at least 5-10 years to develop into clinically detectable cancer, whereby this review is focused on breast cancer. The US National Cancer Institute highlighted a second mechanism of carcinogenicity: certain estrogen metabolites are capable of inducing DNA damage, even in low concentration. They can be assessed in the tissue and circulation. However, those deleterious reactions require excessive unrestricted oxidative cell stress, for example in industrial areas with heavy pollution. We have shown that this can be avoided using transdermal instead of oral estradiol treatment, especially important in smokers. The spectrum of metabolites is also influenced by other exogenous factors such as nutrition, physical activity and certain diseases. Reduction of breast cancer risk as demonstrated in the Women's Health Initiative (WHI) was explained by pro-apoptotic estrogen effects working after a certain 'time gap'. In addition, certain estrogen metabolites are carcinoprotective, if no genetic polymorphisms would impair their beneficial activities. Thus, since additional factors are required for both main pathways of carcinogenicity and because estrogens can even have carcinoprotective effects, we cannot agree with the statement from the WHO.

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.

[Menopause hormone treatment in practice. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Menopause Hormonal Treatment (MHT) was initially developed to correct the climacteric symptoms induced by postmenopausal estrogen deficiency. In non-hysterectomized women, MHT combines estrogens and a progestogen, the latter opposing the negative impact of estrogen on endometrial proliferation. In France, and contrary to the USA and Northern European countries, MHT mainly combines 17β-estradiol, which is the physiological estrogen produced by the ovary, and progesterone or its derivative, dihydrogesterone. France has been a pioneer in the development of cutaneous administration routes (gel or transdermal patch) for estradiol, allowing better metabolic tolerance and a reduction of the risk of venous thromboembolism compared to the oral route. The choice of the doses as well as the treatment regimen is underpinned by tolerance as well as acceptance and compliance. The risk of breast cancer, which is one of the main risks of MHT, is higher with estro-progestogen combinations than with estrogens alone ; the preferential use of progesterone or dihydrogesterone being likely to limit the excess risk of breast cancer associated with MHT at least for duration of treatment of less than 5 to 7 years. The question of the optimal duration of MHT remains an issue and must take into account the initial indication of treatment as well as the benefit-risk balance, which is specific to each woman. Continuation of MHT is conditioned by the benefit-risk balance, which must be evaluated regularly, but also by the evolution of symptoms when MHT is stopped as well as menopause-related health risks or induced by MHT. After stopping MHT, it is necessary to maintain a medical follow-up to be adapted to the clinical situation of each woman and in particular, her cardiovascular and gynecological risk factors.

[Menopausal hormone therapy: internal-endocrine point of view]

The history of menopausal hormone therapy (MHT) started in 1942 in the US and became very popular in the 1960s worldwide because of the beneficial effects on vasomotor-vegetative and vulvovaginal symptoms. These symptoms may begin already in the premenopausal period, and can last for more than 10 years with reduced quality of life. Many women with vasomotor-vegetative symptoms do not visit a gynaecologist first but primarily a general physician or cardiologist because of instable blood pressure and palpitations, leading to the focus on the heart. To avoid unnecessary examinations and treatment with ß-blockers or antidepressants, an interdisciplinary look is necessary. In most cases, appropriate and low dose hormone replacement will relieve the symptoms and restore quality of life. In addition, it is worthwhile to know about the long-term effect of hormone deficiency as well as replacement on the different organ systems and the possible influences of hormone replacement therapy including contra indications. This is especially necessary after the uncertainties raised after the first deleterious announcements of the currently corrected results of the WHI (women's health initiative) study.

Breast effects of oral, combined 17β-estradiol, and progesterone capsules in menopausal women: a randomized controlled trial

Objective:

To evaluate the effect of a single-capsule, bioidentical 17β-estradiol (E2) and progesterone (P4) hormone therapy on mammograms and breasts in postmenopausal women after 1 year of use.

Methods:

In the 12-month, phase 3, randomized, double-blind, placebo-controlled, multicenter REPLENISH trial, postmenopausal women (40-65 y) with moderate to severe vasomotor symptoms and a uterus were randomized to four active daily dose groups of E2/P4 (TX-001HR) or a placebo group. Mammograms were performed and read locally at screening (or ≤6 months before first dose) and at study end using BI-RADS classification. Incidence of abnormal mammograms and breast adverse events was evaluated.

Results:

All but 8 (0.4%) mammograms at screening were normal (BI-RADS 1 or 2). At 1 year, 39 (2.9%) of the 1,340 study-end mammograms were abnormal (BI-RADS 3 or 4); incidence was 1.7% to3.7% with active doses and 3.1% with placebo. Breast cancer incidence was 0.36% with active doses and 0% with placebo. Breast tenderness was reported at frequencies of 2.4% to 10.8% with active doses versus 0.7% with placebo, and led to eight study discontinuations (1.6% of discontinuations in active groups).

Conclusions:

In this phase 3 trial of a combined E2/P4, results of secondary outcomes suggest that E2/P4 may not be associated with increased risk of abnormal mammograms versus placebo, and the incidence of breast tenderness was low relative to most of the rates reported in other studies using hormone therapy.

Hormone Replacement Therapy, Breast Cancer Risk Factors, and Breast Cancer Risk: A Nationwide Population-Based Cohort

BACKGROUND

Hormone replacement therapy (HRT) increases the risk of breast cancer, but the association may vary according to patient factors. We investigated the association between HRT and breast cancer in a nationwide cohort with risk stratification according to risk factors for breast cancer.

METHODS

Using the Korean National Health Insurance Service database, 4,558,376 postmenopausal women who underwent breast cancer screening and regular health checkups from 2009 to 2014 were analyzed.

RESULTS

A total of 696,084 (15.3%) women reported current or previous HRT use. Breast cancer was newly diagnosed in 26,797 (0.6%) women during a median follow-up of 5.35 years. The HR of the risk of breast cancer in HRT users was 1.25 [95% confidence interval (CI), 1.22-1.29] compared with HRT nonusers. The risk of breast cancer increased according to HRT duration [adjusted HR = 1.08; 95% CI, 1.04-1.12, for <2 years; adjusted HR = 1.33; 95% CI, 1.25-1.40, for 2 to <5 years; and adjusted HR = 1.72; 95% CI, 1.63-1.82, for ≥5 years). The effects of HRT on breast cancer risk applied to both invasive and in situ cancer. The HRT-related risk of breast cancer was higher in women who were leaner and those who had dense breasts.

CONCLUSIONS

This nationwide population-based study confirms the association between HRT use and breast cancer risk. The risk increased proportionally with duration of HRT and differed according to body weight and breast density.

IMPACTS

Risk stratification would be useful when deciding whether to apply HRT for relief of menopausal symptoms.

Clinical trials in menopause

OBJECTIVE

Clinical trials in menopause have undergone much scrutiny over the years. This has led to significant shifts in the treatment of symptomatic menopause and a substantial impact on women. We aim to delineate the key studies contributing to this controversy and highlight new directions specifically related to menopausal hormone therapy (HT) and vascular disease risk.

METHODS

We performed a search of sentinel studies delineating the risks and benefits of HT in otherwise healthy postmenopausal women. Using PubMed we input the following search terms: hormone replacement therapy, cardiovascular disease, coronary artery disease, coronary atherosclerosis, myocardial infarction, angina, coronary heart calcification, carotid intimal thickness, lipids, and/or lipoproteins. We included studies of menopausal women (surgical or natural) using combined estrogen/progestogen therapy or estrogen-only therapy that looked at cardiovascular disease risk factors or outcomes. Studies were evaluated for inclusion by the authors; however, this is not intended to be a systematic or an exhaustive analysis.

RESULTS

In women close to the time of menopause, there is a decreased risk of subclinical and clinical coronary heart disease with menopausal HT. Additionally, HT confers a significant benefit to vasomotor symptoms of menopause, bone health, and colorectal cancer. There is an increased risk of venous thromboembolism with oral formulations that appears mitigated with transdermal estradiol. Mixed data regarding breast cancer risk are available, with some studies suggesting an increased risk of invasive breast cancer with estrogen/progestogen therapy and a null effect with estrogen-only therapy. Other more long-term epidemiologic studies identify a decreased risk.

CONCLUSIONS

The available literature suggests that HT is a viable option for the primary prevention of cardiovascular disease in postmenopausal women. Newer trials will likely verify this assessment. If this is enough to change clinical practice, however, remains to be seen given the general fear of HT by many with prescriptive authority, and also the women in our care.

Decline in Instrumental Activities of Daily Living over 4-Year: The Association with Hearing, Visual and Dual Sensory Impairments among Non-Institutionalized Women

OBJECTIVE

Most older adults express the wish to live at home as long as possible, thus autonomy promoting measures are essential. Hearing and visual impairments are common among older people, and they have been consistently associated with functional disability. However, longitudinal data are scarce, notably regarding dual sensory impairments (both in hearing and vision). We aimed at assessing the relationship between hearing, visual, and dual sensory impairments, and subsequent decline in instrumental activities of daily living (IADL).

DESIGN

Longitudinal.

SETTING

the French E3N-elderly sub-cohort.

PARTICIPANTS

4,010 community-dwelling older women born between 1925 and 1930, and free of IADL limitations in 2006.

MEASUREMENTS

Hearing and visual impairments were self-reported in 2006. IADLs were evaluated in 2006 and 2010.

RESULTS

After 4 years of follow-up, 588 women became limited in their IADLs. In logistic regression models adjusted for potential confounders, odds ratios [95% confidence interval] for developing IADL limitations were 1.18 [0.98; 1.41], 1.98 [1.26; 3.11], and 2.61 [1.50; 4.54] for hearing, visual, or both sensory impairments respectively, compared with no sensory impairment at baseline.

CONCLUSION

Results suggest that among autonomous older women, visual, and to a lesser extent, hearing impairment, have a short-term negative impact on their ability to perform daily activities, with some evidence of a multiplicative effect between sensory impairments. Appropriate evaluation and management of sensory impaired elderly, and more particularly those with dual impairments, may contribute to prevent disability in aging.

Transcriptional Downregulation of miR-4306 serves as a New Therapeutic Target for Triple Negative Breast Cancer

Rationale: Triple-negative breast cancer (TNBC) is characterized by the absence of estrogen receptor alpha (ER-α), human epidermal growth factor receptor 2 (HER2) and progesterone receptor (PR) expression, but the effect of lacking the three factors on TNBC is unclear. Whether loss of the three factors contributes to deregulate genes that participate in the progress of TNBC remains unknown. Methods: We performed microRNA arrays and comprehensive analysis to screen for miRNAs that are transcriptionally regulated by ER-α, HER2 and PR. Functional assays and molecular mechanism studies were used to investigate the role of miR-4306 in TNBC. An orthotopic mouse model of TNBC was used to evaluate the therapeutic potential of a cholesterol-conjugated miR-4306 mimic. Results: We found that miR-4306 is transcriptionally regulated by ER-α, HER2 and PR, and the downregulation of miR-4306 in TNBC is caused by the loss of ER-α, HER2 and PR. Clinically, low miR-4306 expression is strongly associated with lymph node metastasis and poor survival for TNBC. Upregulation of miR-4306 greatly suppresses TNBC cell proliferation, migration and invasion and abrogates angiogenesis and lymphangiogenesis in vitro. According to in vivo models, miR-4306 overexpression considerably inhibits TNBC growth, lung metastasis, angiogenesis and lymph node metastasis. Mechanistic analyses indicate that miR-4306 directly targets SIX1/Cdc42/VEGFA to inactivate the signaling pathways mediated by SIX1/Cdc42/VEGFA. Finally, the orthotopic mouse model of TNBC reveals that miR-4306 mimic can be used for TNBC treatment in combination with cisplatin. Conclusions: Our findings suggest that miR-4306 acts as a tumor suppressor in TNBC and is a potential therapeutic target for TNBC treatment.

Hormone therapy use in the Canadian Longitudinal Study on Aging: a cross-sectional analysis

OBJECTIVE

The aim of the study was to assess the prevalence and factors associated with hormone therapy (HT) use among Canadian women.

METHODS

Baseline data from the Tracking cohort of the Canadian Longitudinal Study on Aging (CLSA) was used for this analysis. The main outcome was HT use among women aged 45-85 years, defined as current, past, and never users. Multinomial logistic regression models were used to examine the differences between current, past, and never HT users in terms of sociodemographic, health behavior, and health-related variables.

RESULTS

Overall, 9.5% of the sample reported current use of HT, whereas 21.9% reported past use. The main factors associated with a lower likelihood of current HT use were older age (>80 y), nonwhite ethnic background, current employment, regular smoking, obesity, and breast cancer. By contrast, alcohol consumption, and the presence of allergies or mood disorders were positively associated with current HT use.

CONCLUSIONS

These findings provide a recent national picture of HT use in Canada that may be used to inform opportunities for improved physician-patient communication regarding menopause management.

Personalized prevention in high risk individuals: Managing hormones and beyond

Increasing numbers of women are being identified at 'high-risk' of breast cancer, defined by The National Institute of Health and Care Excellence (NICE) as a 10-year risk of ≥8%. Classically women have been so identified through family history based risk algorithms or genetic testing of high-risk genes. Recent research has shown that assessment of mammographic density and single nucleotide polymorphisms (SNPs), when combined with established risk factors, trebles the number of women reaching the high risk threshold. The options for risk reduction in such women include endocrine chemoprevention with the selective estrogen receptor modulators tamoxifen and raloxifene or the aromatase inhibitors anastrozole or exemestane. NICE recommends offering anastrozole to postmenopausal women at high-risk of breast cancer as cost effectiveness analysis showed this to be cost saving to the National Health Service. Overall uptake to chemoprevention has been disappointingly low but this may improve with the improved efficacy of aromatase inhibitors, particularly the lack of toxicity to the endometrium and thrombogenic risks. Novel approaches to chemoprevention under investigation include lower dose and topical tamoxifen, denosumab, anti-progestins and metformin. Although oophorectomy is usually only recommended to women at increased risk of ovarian cancer it has been shown in numerous studies to reduce breast cancer risks in the general population and in those with mutations in BRCA1/2. However, recent evidence from studies that have confined analysis to true prospective follow up have cast doubt on the efficacy of oophorectomy to reduce breast cancer risk in BRCA1 mutation carriers, at least in the short-term.

Menopausal hormone therapy: a better and safer future

Major advances in menopause hormone therapy (MHT) hold promise in the future of better and safer care for women at and after the menopause. The principal advances are: (1) the critical window or 'window of opportunity' in the 10 years or so after the menopause, during which the benefits of MHT in healthy women exceed any risks; (2) use of transdermal instead of oral administration of estrogen to reduce the risk of venous thromboembolism; (c) investigation of the use of oral micronized progesterone (MP) and vaginal MP to prevent endometrial hyperplasia and carcinoma without any increased risk of breast cancer and venous thromboembolism in postmenopausal women receiving estrogens; vaginal MP prevents endometrial proliferation in the short term but the long-term effects in MHT remain to be established; (4) investigation into the use of intrauterine levonorgestrel-releasing devices (LNG-IUDs), which are an attractive form of MHT in perimenopausal women, providing contraception and reducing uterine bleeding, although the risk of breast cancer with LNG-IUDs requires clarification. Women in the future can look forward to a symptom-free menopause and to safer and more beneficial MHT.

The impact of micronized progesterone on breast cancer risk: a systematic review

Postmenopausal women with an intact uterus using estrogen therapy should receive a progestogen for endometrial protection. The debate on bioidentical hormones including micronized progesterone has increased in recent years. Based on a systematic literature review on the impact of menopausal hormone therapy (MHT) containing micronized progesterone on the mammary gland, an international expert panel's recommendations are as follows: (1) estrogens combined with oral (approved) or vaginal (off-label use) micronized progesterone do not increase breast cancer risk for up to 5 years of treatment duration; (2) there is limited evidence that estrogens combined with oral micronized progesterone applied for more than 5 years are associated with an increased breast cancer risk; and (3) counseling on combined MHT should cover breast cancer risk - regardless of the progestogen chosen. Yet, women should also be counseled on other modifiable and non-modifiable breast cancer risk factors in order to balance the impact of combined MHT on the breast.

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.

Change in risk of breast cancer after receiving hormone replacement therapy by considering effect-modifiers: a systematic review and dose-response meta-analysis of prospective studies

We synthesize the current literatures and use the power of meta-analysis to examine trends on association between hormone replacement therapy (HRT) and the risk of breast cancer (BC). We performed a comprehensive literature search using PubMed, EMBASE, and Web of Science from their inception until Jan 2017. Prospective studies that provided adjusted risk estimates of HRT and BC risk were eligible. Categorical and dose-response meta-analyses followed the PRISMA were conducted using random effects model and restricted cubic spline model, respectively. Forty-seven publications from thirty-five unique studies were included, involving 3,898,376 of participants and 87,845 of BC cases. Compared with non-users, RR for current estrogen-only therapy (ET) users was 1.14 (95% confidence interval (CI) = 1.05–1.22), and for per year increases was 1.02 (95% CI = 1.02–1.02). Moreover, RR for current estrogen plus progestin therapy (EPT) users was 1.76, (95% CI = 1.56–1.96), and for per year increases was 1.08 (95% CI = 1.08–1.08). Dose-response analyses revealed 8–10 years’ onset peaks, and indicated residual increased BC risk remained after stopping use of ET regimen rather than for EPT. Effect-modifiers like BMI, duration of use, race/ethnicity, routes of administration were recognized. In Conclusions, current use of EP or EPT and ever use of tibolone are associated with an elevated risk of BC. Compared with slim HRT users and non-users, lower BC risks were found among overweight/obese HRT users and former EPT users, respectively. Both ET and EPT users are associated with higher risk of lobular BC than ductal BC, and more ER-positive than negative BC cases were detected among EPT users.

Bioidentical menopausal hormone therapy: registered hormones (non-oral estradiol ± progesterone) are optimal

The many advantages of registered bioidentical sex hormones over registered, conventional, non-bioidentical menopausal hormone therapy (MHT) are considered. The transdermal route of estrogen administration avoids excess venous thromboembolic and ischemic stroke events. There is some indication that conjugated equine estrogens are more thrombogenic and most likely induce some hypertensive responses; estradiol might also be superior to conjugated equine estrogens (CEE) in terms of global cardiovascular health. The most valid evidence presently suggests that CEE-only treatment does not increase the risk of breast cancer and even may reduce it. But its combination with a synthetic progestogen (mainly medroxyprogesterone acetate) is a critical issue since it seems to be primarily associated with an increased incidence of breast cancer, however similar to or lower than that associated with some common lifestyle factors. Though not yet proven in a randomized, controlled trial, MHT continuously combining oral micronized progesterone with transdermal estradiol can presently be considered as the optimal MHT. It is not only safer than custom-compounded bioidentical hormones but also than oral conventional MHT and has the best breast profile; registered products for such optimal MHT are available around the world and must be preferred.

Menopausal Hormone Therapy, Age, and Chronic Diseases: Perspectives on Statistical Trends

The release of the Women's Health Initiative (WHI) study in 2002 was a shock to the medical community. Hormone therapy (HT) had generally been considered to be highly beneficial for postmenopausal women since it was the gold standard for relief of menopausal symptoms (hot flashes, night sweats, vaginal atrophy) and it was thought to protect women from osteoporosis, heart disease, and cognitive decline and to generally improve quality of life. However, WHI showed a statistically significant increase in a number of disease states, including breast cancer, cardiovascular disease, and stroke. One problem with the WHI study was that the average age of women in the study was 63, which is considerably older than the age at which most women enter menopause (about 51). The timing hypothesis attempts to rationalize the effect of age on response to HT and risk of various diseases. The data suggests that younger women (50-60) may be protected from heart disease with only a slight increase in breast cancer risk. In contrast, older women (>65) are more susceptible to breast cancer and heart disease and should avoid HT. This Perspective on Statistical Trends evaluates the current data on HT and risk for chronic diseases as a function of age.

[Menopausal hormonal therapy and cancer risks]

Estrogen-progestagen menopausal hormonal therapy (MHT) is recognized as carcinogenic to humans. The article presents the associations between MHT and breast, ovary and endometrial cancer risks, in particular according to treatment modalities. If MHT must be prescribed, it is recommended to use the lowest dose for the shortest possible duration. Discussing with the patient the benefits but also the risks and making regular gynecological follow-up are strongly encouraged.

European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer

The 4th edition of the European Code against Cancer recommends limiting - or avoiding when possible - the use of hormone replacement therapy (HRT) because of the increased risk of cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal hormone therapy, is associated with an increased risk of cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of therapy (oestrogen-only or combined oestrogen-progestogen), duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in cancer therapy, immunosuppressants, oestrogen-progestogen contraceptives, and tamoxifen. Medical use of ionising radiation, an established carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to cancer-preventive drugs, and self-medication with aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.

Bridging progestogens in pregnancy and pregnancy prevention

Steroid hormones have been in use for more than a half a century as contraceptive agents, and only now are researchers elucidating the biochemical mechanisms of action and non-target effects. Progesterone and synthetic progestins, critical for women's health in the US and internationally, appear to have important effects on immune functioning and other diverse systems. Apart from the contraceptive world is a separate field that is devoted to understanding progesterone in other contexts. Based on research following a development timeline parallel to hormonal contraception, progesterone and 17-hydroxyprogesterone caproate are now administered to prevent preterm birth in high-risk pregnant women. Preterm birth researchers are similarly working to determine the precise biochemical actions and immunological effects of progesterone. Progesterone research in both areas could benefit from increased collaboration and bringing these two bodies of literature together. Progesterone, through actions on various hormone receptors, has lifelong importance in different organ systems and researchers have much to learn about this molecule from the combination of existing literatures, and from future studies that build on this combined knowledge base.

Postmenopausal Female Hormone Use and Estrogen Receptor-Positive and -Negative Breast Cancer in African American Women

BACKGROUND

Use of estrogen with progestin (combination therapy) is associated with increased incidence of estrogen receptor-positive (ER+) breast cancer in observational studies and randomized trials among postmenopausal white women. Whether this is also the case among African American women is not established.

METHODS

Using data from the AMBER consortium collected from 1993 to 2013, we assessed use of estrogen alone and of combination therapy in relation to ER+ and ER-negative (ER-) breast cancer risk in postmenopausal African American women, based on 1132 ER+ case patients, 512 ER- case patients, and 6693 control patients. Odds ratios (ORs) and confidence intervals (CIs) were estimated using multinomial logistic regression with control for breast cancer risk factors.

RESULTS

Forty-seven percent of control patients had used estrogen alone, combination therapy, or both. The odds ratio for ER+ breast cancer associated with combination use, relative to never use of either estrogen alone or combination therapy, was 1.50 (95% CI = 1.25 to 1.79). The increase was greater for recent (OR = 1.55, 95% CI = 1.21 to 1.99) and long-term use (OR = 1.75, 95% CI = 1.13 to 2.73) and among nonobese women (OR = 1.91, 95% CI = 1.29 to 2.83). Breast cancer risk was increased regardless of the interval between onset of menopause and initiation of combination use (OR = 1.43, 95% CI = 1.11 to 1.85, for <5 year interval; OR = 1.78, 95% CI = 1.34 to 2.37, for ≥5 year interval). Combination use was not associated with risk of ER- breast cancer, and use of estrogen alone was not associated with risk of either ER+ or ER- breast cancer.

CONCLUSION

Use of estrogen with progestin increases risk of ER+ breast cancer in African American women. A decrease in use would be expected to reduce the number of ER+ cancers.

Menopausal hormone therapy use in relation to breast cancer incidence in 11 European countries

INTRODUCTION

The use of menopausal hormone therapy (MHT) has decreased in many countries in the past 10 years. This is a consequence of the initial publication of the results of the Women's Health Initiative (WHI) randomized trial of estrogen plus progestin. In various countries, further studies then analyzed the incidence of breast cancer (BC) in relation to changes in MHT use. Some reported a decreased BC incidence following cessation of MHT, but others did not. This may reflect differences in BC incidence, in MHT use or in confounding factors, but also in study methodology.

AIM

To analyze the changes in BC incidence and MHT use, using the same methodology, in 11 European countries.

MATERIALS & METHOD

We limited the study to women between the ages of 45 and 69. BC incidence data were provided from cancer registries. MHT sales data were extracted from health sales databases for the years 2003-2013. The association between BC incidence and the rate of MHT use during the past year in Europe was assessed using linear mixed models.

RESULTS

A drop in MHT sales was consistent in all countries for the whole period of follow-up. This was not the case for BC incidence. We found no evidence of a relation between BC incidence and MHT sales in the past year, except for sales of tibolone.

CONCLUSIONS

The longer observation period did not confirm the results of studies that had a shorter follow-up, except in relation to tibolone. The role of confounding factors needs to be clarified.

Evaluation of steroidomics by liquid chromatography hyphenated to mass spectrometry as a powerful analytical strategy for measuring human steroid perturbations

This review presents the evolution of steroid analytical techniques, including gas chromatography coupled to mass spectrometry (GC-MS), immunoassay (IA) and targeted liquid chromatography coupled to mass spectrometry (LC-MS), and it evaluates the potential of extended steroid profiles by a metabolomics-based approach, namely steroidomics. Steroids regulate essential biological functions including growth and reproduction, and perturbations of the steroid homeostasis can generate serious physiological issues; therefore, specific and sensitive methods have been developed to measure steroid concentrations. GC-MS measuring several steroids simultaneously was considered the first historical standard method for analysis. Steroids were then quantified by immunoassay, allowing a higher throughput; however, major drawbacks included the measurement of a single compound instead of a panel and cross-reactivity reactions. Targeted LC-MS methods with selected reaction monitoring (SRM) were then introduced for quantifying a small steroid subset without the problems of cross-reactivity. The next step was the integration of metabolomic approaches in the context of steroid analyses. As metabolomics tends to identify and quantify all the metabolites (i.e., the metabolome) in a specific system, appropriate strategies were proposed for discovering new biomarkers. Steroidomics, defined as the untargeted analysis of the steroid content in a sample, was implemented in several fields, including doping analysis, clinical studies, in vivo or in vitro toxicology assays, and more. This review discusses the current analytical methods for assessing steroid changes and compares them to steroidomics. Steroids, their pathways, their implications in diseases and the biological matrices in which they are analysed will first be described. Then, the different analytical strategies will be presented with a focus on their ability to obtain relevant information on the steroid pattern. The future technical requirements for improving steroid analysis will also be presented.

Menopausal hormone therapy and breast cancer mortality: clinical implications

The Women's Health Initiative (WHI) has conducted two randomized, placebo-controlled clinical trials to evaluate the influence of menopausal hormone therapy on chronic disease risk. Estrogen plus progestin was evaluated in 16,608 postmenopausal women without prior hysterectomy during 5.6 years' intervention. In that setting, combined hormone therapy use significantly increased breast cancer incidence and interfered with breast cancer detection. The breast cancers were not limited to estrogen receptor positive, favorable prognosis cancers and were identified at more advanced stage. As a result, deaths from breast cancer were significantly increased by estrogen plus progestin use. While the absolute breast cancer risk for relatively short term (2-4 years) use of combined hormone therapy is small, on a population basis a therapy which nearly doubles deaths from breast cancer requires cautious use. Estrogen alone was evaluated in 10,739 postmenopausal women with prior hysterectomy during 7.1 years' intervention. There was an overall reduction of breast cancer incidence seen with estrogen alone use and a suggestion that the effect on risk was more pronounced in women initiating hormone therapy further from menopause. Nonetheless, women with prior hysterectomy can be assured that short duration estrogen alone use for climacteric symptom management is relatively safe. Neither estrogen plus progestin nor estrogen alone should be used for chronic disease risk reduction. The safety of duration of use on chronic disease risk longer than in the WHI clinical trials is not defined.

Radiation meets immunotherapy - a perfect match in the era of combination therapy?

PURPOSE

This review focuses on recent advances in the field of combining radiation with immunotherapy for the treatment of malignant diseases, since various combinatorial cancer therapy approaches have lately proven highly successful.

RESULTS

With initial case reports and anecdotes progressively converting into solid clinical data, interest in cancer immunotherapy (CIT) has risen steeply. Especially immune checkpoint blockade therapies have recently celebrated tremendous successes in the treatment of severe malignancies resistant to conventional treatment strategies. Nevertheless, the high variability of patient responses to CIT remains a major hurdle, clearly indicating an urgent need for improvement. It has been suggested that successful cancer therapy most probably involves combinatorial treatment approaches. Radiotherapy (RT) has been proposed as a powerful partner for CIT due to its broad spectrum of immune modulatory characteristics. Several preclinical studies, supported by an increasing number of clinical observations, have demonstrated synergistic interactions between RT and CIT resulting in significantly improved therapy outcomes.

CONCLUSIONS

Numerous reports have shown that radiation is capable of tipping the scales from tumor immune evasion to elimination in different tumor types. The next puzzle to be solved is the question of logistics - including types, schedule and dosage of combinatorial RT and CIT strategies.

Alcohol and breast cancer: reconciling epidemiological and molecular data

Breast cancer is the most diagnosed cancer in women worldwide. Epidemiological studies have suggested a possible causative role of alcohol consumption as a risk factor for breast cancer. However, such conclusions should be interpreted with considerable caution for several reasons. While epidemiological studies can help identify the roots of health problems and disease incidence in a community, they are by necessity associative and cannot determine cause and effect relationships. In addition, all these studies rely on self-reporting to determine the amount and type of alcoholic beverage consumed, which introduces recall bias. This is documented in a recent study which stated that the apparent increased risk of cancer among light-moderate drinkers may be "substantially due to underreporting of intake." Another meta-analysis about alcohol and breast cancer declared "the modest size of the association and variation in results across studies leave the causal role of alcohol in question." Furthermore, breast cancer develops over decades; thus, correlations between alcohol consumption and breast cancer cannot be determined in epidemiological studies with windows of alcohol exposure that captures current or recent alcohol intake, after clinical diagnosis. Numerous risk factors are involved in breast carcinogenesis; some are genetic and beyond the control of a woman; others are influenced by lifestyle factors. Breast cancer is a heterogeneous and polygenic disease which is further influenced by epigenetic mechanisms that affect the transciptomes, proteomes and metabolomes, and ultimately breast cancer evolution. Environmental factors add another layer of complexity by their interactions with the susceptibility genes for breast cancer and metabolic diseases. The current state-of-knowledge about alcohol and breast cancer association is ambiguous and confusing to both a woman and her physician. Confronting the huge global breast cancer issue should be addressed by sound science. It is advised that women with or without a high risk for breast cancer should avoid overconsumption of alcohol and should consult with their physician about risk factors involved in breast cancer. Since studies associating moderate alcohol consumption and breast cancer are contradictory, a woman and her physician should weigh the risks and benefits of moderate alcohol consumption.

Menopausal hormone therapy and cancer: changing clinical observations of target site specificity

Menopausal hormone therapy with estrogen plus progestin or estrogen alone (for women with prior hysterectomy) is still used by millions of women for climacteric symptom management throughout the world. Until 2002, hormone therapy influence on cancer risk and other chronic diseases was determined through observational study reports. Since then, results from the Women's Health Initiative randomized, placebo-controlled hormone therapy trials have substantially changed concepts regarding estrogen plus progestin and estrogen alone influence on the most common cancers in postmenopausal women. In these trials, estrogen plus progestin significantly increased breast cancer incidence and deaths from breast cancer, significantly increased deaths from lung cancer, significantly decreased endometrial cancer, and did not have a clinically significant influence on colorectal cancer. In contrast, estrogen alone use in women with prior hysterectomy significantly reduced breast cancer incidence and deaths from breast cancer without significant influence on colorectal cancer or lung cancer. These complex results are discussed in the context of known potential mediating mechanisms of action involved in interaction with steroid hormone receptors.

Is breast cancer risk the same for all progestogens?

The population-based case–control study CECILE investigated the impact of various menopausal hormone therapy (MHT) products on breast cancer (BC) risk in 1,555 postmenopausal women [1]. The case group (n = 739) included incident cases of in situ (!) or invasive BC in postmenopausal women. The control group (n = 816) included women from the general population within predefined quotas by age and socio-economic status (SES). While quotas by age were applied to obtain similar distributions by age among controls and among cases, quotas by SES in control women were applied to reflect the distribution by SES of women in the general population in the study area. Data of participants were obtained by a structured questionnaire during in-person interviews, and from pathology reports if applicable, respectively. Women were divided into current and past MHT user. MHTs were classified in estrogen-only therapy (ET), estrogen combined with progestin therapy (EPT) and tibolone. EPT was subdivided in three subtypes according to the progestogen constituent: natural micronized progesterone, progesterone derivatives, and testosterone derivatives. In comparison to never MHT users, any current or past MHT use (ET, EPT, tibolone) was not associated with an increased BC risk. However, in subanalysis BC risk was significantly increased for current use of EPT for 4 or more years (n = 73 cases and n = 56 controls, adjusted OR 1.55; 95 % CI 1.02–2.36). Within the group of current EPT users for 4 or more years, 14 cases had used estrogens combined with micronized progesterone (n = 17 controls), and 55 a combination with a synthetic progestogen (n = 34 controls), respectively. Compared to never MHT use, current use of EPT containing a synthetic progestogen for 4 or more years was associated with a significantly increased BC risk (adjusted OR 2.07; 95 % CI 1.26–3.39), but EPT containing micronized progesterone was not (adjusted OR 0.79; 95 % CI 0.37–1.71). 73 % of current MHT users started treatment within the first year of onset of menopause. Early EPT (n = 52 cases and n = 38 controls, adjusted OR 1.65; 95 % CI 1.02–2.69), but not early ET, starters had a significantly higher BC risk compared to never MHT users. In contrast, MHT initiation beyond 1 year after menopause was not associated with an increased BC risk. The authors concluded that: (1) ET and EPT containing natural progesterone did not increase BC risk whereas, (2) BC risk was increased in users of tibolone or EPT containing a synthetic progestogen, respectively, and that (3) MHT use early after onset of menopause was associated with an increased BC risk as compared to women who delay MHT beyond 1 or more years.

Cohort Profile: The French E3N Cohort Study

The E3N (Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale) cohort was initiated in 1990 to investigate therisk factors associated with cancer and other major non-communicable diseases in women. The participants were insured through a national health system that primarily covered teachers, and were enrolled from 1990 after returning baseline self-administered questionnaires and providing informed consent. The cohort comprised nearly 100,000 women with baseline ages ranging from 40 to 65 years. Follow-up questionnaires were sent approximately every 2-3 years after the baseline and addressed general and lifestyle characteristics together with medical events (cancer, cardiovascular diseases, diabetes, depression, fractures and asthma, among others). The follow-up questionnaire response rate remained stable at approximately 80%. A biological material bank was generated and included blood samples collected from 25,000 women and saliva samples from an additional 47,000 women. Ageing among the E3N cohort provided the opportunity to investigate factors related to age-related diseases and conditions as well as disease survival. The new E4N complementary cohort (Epidemiology 4 kNowledge), which comprises the children and grandchildren of the E3N cohort as well as the children's fathers, will allow researchers to investigate key life periods during which exposures to environmental factors most strongly influence the later disease risk. The E3N and E4N cohort data will be used to investigate diseases and risk factors through a transgenerational approach. Requests for collaborations are welcome, particularly those in conjunction with rare diseases.

Menopausal hormone therapy use in 17 European countries during the last decade

INTRODUCTION

The first 'Women's Health Initiative' (WHI) randomised controlled trial assessed use of continuous combined menopausal hormone therapy (cc-MHT). It was prematurely stopped because of an increased invasive breast cancer (BC), coronary heart disease (CHD), stroke and pulmonary embolism risk. Consequently, scientific societies recommended use of MHT at the lowest effective dose for the shortest duration. As a result, a sharp decline in MHT use occurred worldwide.

AIM

To report in a uniform way the change in MHT use in European countries. To evaluate whether the variability of the MHT changes were related to some medical indicators.

MATERIALS AND METHODS

IMS Health provided MHT sales data for the years 2002 till 2010 for 17 countries. We tested several hypotheses to explain the heterogeneity of MHT use changes.

RESULTS AND DISCUSSION

In 2002, the estimated MHT rate in women 45-69 years old varied considerably between countries ranging from less than 5% to more than 25%. In all countries a profound decrease occurred between 2002 and 2010, ranging from 50% to 77%. By the end of 2010, the MHT uptake was lower than 10% in all countries except in Finland. MHT use change was not correlated to MHT use and prevailing BC incidence at baseline, nor to the number of gynaecologists per 100,000 women or to the level of information about MHT.

CONCLUSION

The global MHT use experienced a sharp decrease in all the analysed countries, although some variability exists. The decrease was unrelated to the assessed parameters.

Menopausal hormone therapy and breast cancer

Observational and randomized controlled trial data have extensively examined the relationship between menopausal hormone therapy (MHT) and risk of developing breast cancer. A highly influential study from the Women's Health Initiative (WHI) in 2002 reported that a MHT regimen of conjugated equine estrogens and medroxyprogesterone acetate increased the risk of breast cancer by 26%. Later reports from the WHI indicated that a MHT regimen with conjugated equine estrogens alone decreased the risk of breast cancer by 23%. Critical re-examination of the WHI study noted that the average participant age was 63, that few women had symptoms, and that the WHI results might not apply to younger, symptomatic women shortly after menopause. Since the original publications, several post hoc analyses and observational studies have stimulated reconsideration of the WHI findings. Emphasis has been directed toward risks in younger women just entering the menopause, the subgroup who are most likely to be considering MHT use. The goal of this treatise is to integrate available mechanistic and clinical information related to the use of estrogen alone or estrogen plus a progestogen for five years or less. These data suggest that estrogen alone neither decreases nor increases risk in younger women initiating therapy close to the time of menopause but decreases risk in older women. Both younger and older women experience an excess risk with estrogen plus a progestogen. The attributable risk in younger women is less in those with a low underlying Gail Model risk score. Effects of MHT on risk largely reflect actions on pre-existing, occult, undiagnosed breast cancers. Tumor kinetic models suggest that the pro-proliferative effects of estrogen plus a progestogen on occult tumors provide a mechanistic explanation for the increased risk with this therapy. Pro-apoptotic effects of estrogen alone may explain the reduction of breast cancer in women starting this therapy at an average age of 63 as reported in the WHI study. This article is part of a Special Issue entitled 'Menopause'.

Risk of breast cancer after stopping menopausal hormone therapy in the E3N cohort

Questions remain on how the excess risk of breast cancer associated with menopausal hormone therapy (MHT) evolves after treatment stops. We investigated that issue in the E3N cohort, with 3,678 invasive breast cancers identified between 1992 and 2008 among 78,353 women (881,290 person-years of postmenopausal follow-up). Exposure to MHT was assessed through biennial self-administered questionnaires and classified by type of progestagen component (progesterone or dydrogesterone; other progestagen), duration (short-term ≤5 years; long-term >5 years) and time since last use (current, 3 months-5 years, 5-10 years, 10+ years). Hazard ratios (HR) and confidence intervals (CI) were estimated with Cox models. Among short-term users, only those currently using estrogens associated with a progestagen other than progesterone/dydrogesterone had a significantly elevated breast cancer risk (HR 1.70, 95 % CI 1.50-1.91, compared with never users). Long-term use of this type of MHT was associated with a HR of 2.02 (1.81-2.26) when current and of 1.36 (1.13-1.64), 1.34 (1.04-1.73), and 1.52 (0.87-2.63) when stopped ≤5, 5-10, and 10+ years earlier, respectively. Our results suggest residual increases in breast cancer risk several years after MHT cessation, which are restricted to long-term treatments. Whether increases persist more than 10 years after cessation deserves continuing investigation.

Body identical hormone replacement

The adverse outcomes seen in the Women's Health Initiative (WHI) ¹ were mainly due to an over-dosage of hormones in a relatively elderly population. However, fundamental differences exist between conjugated equine estrogens and 17 beta estradiol and between medroxyprogesterone acetate and natural progesterone. It is likely that these differences also contributed to the adverse outcomes in WHI, which were contrary to the cardiovascular benefits seen in previous observational trials. Recent studies of cardiovascular risk markers in younger women have been designed using predominantly estradiol and natural progesterone (transdermal and oral) as the primary interventions. This paper reviews the effects that body identical estradiol and progesterone can have, both in the physiological environment and also when replaced as transdermal estradiol and micronised oral progesterone.

[Still a place for hormone replacement therapy?]

Hormone replacement therapy (HRT) remains the most efficient treatment to alleviate climacteric symptoms. The drastic decline in their prescription following the WHI is not fully justified. Benefits might be more important than harm in women 50-60 years. French way of treatment does not increase the risk in thrombosis nor stroke and breast cancer risk is less important than with other regimen. One of the major benefits of HRT is the decrease in type 2 diabetes with all the treatments including the French ones. The results of the American randomized trials cannot be fully extrapolated to young postmenopausal women with less cardiovascular risk factors.

Risk of breast cancer by type of menopausal hormone therapy: a case-control study among post-menopausal women in France

Background

There is extensive epidemiological evidence that menopausal hormone therapy (MHT) increases breast cancer risk, particularly combinations of estrogen and progestagen (EP). We investigated the effects of the specific formulations and types of therapies used by French women. Progestagen constituents, regimen (continuous or sequential treatment by the progestagen), and time interval between onset of menopause and start of MHT were examined.

Methods

We conducted a population-based case-control study in France in 1555 menopausal women (739 cases and 816 controls). Detailed information on MHT use was obtained during in-person interviews. Odds ratios and 95% confidence interval adjusted for breast cancer risk factors were calculated.

Results

We found that breast cancer risk differed by type of progestagen among current users of EP therapies. No increased risk was apparent among EP therapy users treated with natural micronized progesterone. Among users of EP therapy containing a synthetic progestin, the odds ratio was 1.57 (0.99-2.49) for progesterone-derived and 3.35 (1.07-10.4) for testosterone-derived progestagen. Women with continuous regimen were at greater risk than women treated sequentially, but regimen and type of progestagen could not be investigated independently, as almost all EP combinations containing a testosterone-derivative were administered continuously and vice-versa. Tibolone was also associated with an increased risk of breast cancer. Early users of MHT after onset of menopause were at greater risk than users who delayed treatment.

Conclusion

This study confirms differential effects on breast cancer risk of progestagens and regimens specifically used in France. Formulation of EP therapies containing natural progesterone, frequently prescribed in France, was not associated with increased risk of breast cancer but may poorly protect against endometrial cancer.

Systematic review about breast cancer incidence in relation to hormone replacement therapy use

BACKGROUND

Several studies report a decrease in breast cancer incidence subsequent to the decrease in hormone replacement therapy (HRT) use. But its magnitude and the time-lag may vary between countries. This may reflect differences in populations, previous type and prevalence of HRT use and breast cancer screening.

AIM

To review systematically studies assessing the relation between breast cancer incidence and change of HRT use.

MATERIAL AND METHOD

Descriptive analysis of the methodology of the studies including design limitations and presence of confounding factors, data sources for breast cancer and HRT and regimens of HRT used.

RESULTS AND DISCUSSION

Eighteen articles were selected. Most studies were ecological and confounding factors such as mammography screening and changes in reproductive and lifestyle habits could not be excluded. Sources of data on breast cancer and HRT were heterogeneous and only few data on HRT regimens used were available. Most studies concluded that the decrease in HRT use during the last decade was probably associated with a decrease in breast cancer incidence, especially for women aged 50 years or more.

CONCLUSIONS

Data, mostly from epidemiological studies, suggest that the decrease in breast cancer incidence can be partly attributed to the drop in HRT use. Nevertheless, available studies are hampered by a number of limitations and it remains difficult to evaluate the exact impact of the drop in HRT use on the decrease in breast cancer incidence. Especially, the studies are seldom based on detailed individual data and do not provide information on regimens used, type of cancers and possible confounding factors.

Revisiting the roles of progesterone and allopregnanolone in the nervous system: resurgence of the progesterone receptors

Progesterone is commonly considered as a female reproductive hormone and is well-known for its role in pregnancy. It is less well appreciated that progesterone and its metabolite allopregnanolone are also male hormones, as they are produced in both sexes by the adrenal glands. In addition, they are synthesized within the nervous system. Progesterone and allopregnanolone are associated with adaptation to stress, and increased production of progesterone within the brain may be part of the response of neural cells to injury. Progesterone receptors (PR) are widely distributed throughout the brain, but their study has been mainly limited to the hypothalamus and reproductive functions, and the extra-hypothalamic receptors have been neglected. This lack of information about brain functions of PR is unexpected, as the protective and trophic effects of progesterone are much investigated, and as the therapeutic potential of progesterone as a neuroprotective and promyelinating agent is currently being assessed in clinical trials. The little attention devoted to the brain functions of PR may relate to the widely accepted assumption that non-reproductive actions of progesterone may be mainly mediated by allopregnanolone, which does not bind to PR, but acts as a potent positive modulator of γ-aminobutyric acid type A (GABA(A) receptors. The aim of this review is to critically discuss effects of progesterone on the nervous system via PR, and of allopregnanolone via its modulation of GABA(A) receptors, with main focus on the brain.

Hormone replacement therapy and breast cancer: heterogeneous risks by race, weight, and breast density

BACKGROUND

Although studies have demonstrated a positive association between hormone replacement therapy (HRT) and breast cancer risk, this association may vary by patient factors.

METHODS

We analyzed 1642824 screening mammograms with 9300 breast cancer cases in postmenopausal women aged 45 years or older derived from the Breast Cancer Surveillance Consortium, a longitudinal registry of mammography screening in the United States. Multiple imputation methods were used to accommodate missing data for HRT use (14%) and other covariables. We performed logistic regression to estimate odds ratios (ORs) for breast cancer associated with HRT use within strata of race/ethnicity, age, body mass index (BMI), and breast density, with two-way interaction terms between HRT use and each key covariable of interest. P values for assessing possible interactions were computed from Wald z statistics. All statistical tests were two-sided.

RESULTS

HRT use was associated with greater than 20% increased risk in white (OR = 1.21; 95% CI = 1.14 to 1.28), Asian (OR = 1.58; 95% CI = 1.18 to 2.11), and Hispanic women (OR = 1.35; 95% CI = 1.09 to 1.67) but not black women (OR = 0.91; 95% CI = 0.72 to 1.14; P interaction = .04). In women with low/normal BMI and extremely dense breasts, HRT use was associated with the highest breast cancer risk (OR = 1.49; 95% CI = 1.21 to 1.83), compared with nonusers. In overweight/obese women with less-dense breasts, no excess risk was associated with HRT use (adjusted ORs = 0.96 to 1.03).

CONCLUSIONS

The impact of HRT use on breast cancer risk varies according to race/ethnicity, BMI, and breast density. This risk stratification could help in advising HRT use for the relief of menopausal symptoms.

Possible role of PGRMC1 in breast cancer development

Hormone therapy may increase the risk of breast cancer. Thus, especially the addition of synthetic progestins may play a decisive role according to the results of clinical studies. Overexpression of a special receptor, i.e. the progesterone receptor membrane component-1 (PGRMC1), may offer a potential new pathway to explain the observed increase in breast cancer risk in the combined arm of the Women's Health Initiative. PGRMC1 is expressed in breast cancer tissue and may be important in tumorigenesis. The expression of PGRMC1 in breast cancer tissue is significantly different from that in normal mammary glands. Certain synthetic progestins can increase the proliferation of PGRMC1-overexpressing breast cancer cells and may thus be involved in tumorigenesis, while progesterone and certain synthetic progestins such as nomegestrol or chlormadinone acetate react neutrally. Our investigations point towards an important role of estrogen receptor-α in the signaling cascade, resulting in the proliferative effect induced by progestins. Thus, activation of PGRMC1 may explain the increased breast cancer risk observed during treatment with certain progestins. Very recently, PGRMC1 was investigated in serum samples of lung cancer patients and matched healthy patients; significantly higher concentrations were shown in the cancer patients. Therefore, PGRMC1 might be a predictor for other cancers as well but, according to clinical trials, its importance for a possible screening tool, particularly for breast cancer risk during hormone therapy, seems of interest.

Postmenopausal hormone therapy: risks and benefits

Postmenopausal hormone therapy (PMHT) is used for the relief of menopausal symptoms, but the dosage has varied greatly throughout its existence. By the end of the 1990s, PMHT was mainly used to prevent chronic diseases such as osteoporosis, coronary heart disease and dementia, and large prevention trials were undertaken in this context. Following the initial negative reports of these trials, use of PMHT dramatically decreased. These reports noted surprisingly increased risks, notably of coronary heart disease, stroke and breast cancer, in people who used PMHT. Nowadays, considering the currently available data, it seems that an important distinction should be made between the treatment of climacteric symptoms in young, generally healthy, postmenopausal women and the prevention of chronic diseases in elderly women. PMHT seems to be beneficial and safe for postmenopausal symptomatic women aged <60 years. Treatments with a high safety profile should be the preferred option, including low-dose PMHT, oestrogen-only therapy in women who have had a hysterectomy, and vaginal oestrogen therapy for women with atrophic vaginitis. Nonandrogenic progestin might have a reduced thrombotic and breast cancer risk, and transdermal oestrogen could have a reduced thrombotic risk. Nevertheless, PMHT should not be used for the prevention of chronic diseases in the elderly (>70 years old) owing to the increased risk of stroke and breast cancer in these patients.