Low-dose and ultra-low-dose estradiol and dydrogesterone in postmenopause: an analysis by body mass index.

OBJECTIVE: Oral, low-dose and ultra-low-dose continuous combined 17ß-estradiol (E) plus dydrogesterone (D) reduce vasomotor symptoms (VMS) in postmenopausal women. METHODS: Two phase 3, double-blind studies were included. In the European study, postmenopausal women were randomized 2:1:2 to receive E0.5 mg/D2.5 mg (ultra-low dose), E1 mg/D5 mg (low dose) or placebo for 13 weeks. In the Chinese study, women were randomized 1:1 to receive E0.5 mg/D2.5 mg or placebo for 12 weeks. Post-hoc endpoints assessed in body mass index (BMI) subgroups (<25 kg/m2; ≥25 kg/m2) included number of hot flushes and moderate-to-severe hot flushes per day, and the proportion of women with amenorrhea. RESULTS: A total of 640 women were included. At the end of treatment, the mean (95% confidence interval) numbers of daily hot flushes were significantly lower (p ≤ 0.05) for all treatment groups versus placebo, with E0.5 mg/D2.5 mg (BMI < 25 kg/m2: 2.5 [1.9, 3.1]; BMI ≥ 25 kg/m2: 3.2 [2.5, 3.8]) and E1 mg/D5 mg versus placebo (BMI < 25 kg/m2: 2.7 [1.2, 4.2]; BMI ≥ 25 kg/m2: 2.3 [1.1, 3.5]) than with placebo (BMI < 25 kg/m2: 4.4 [3.8, 50]; BMI ≥ 25 kg/m2: 4.2 [3.6, 4.9]). A similar pattern was seen for moderate-to-severe hot flushes. The amenorrhea rate was high (79-98%) across both studies and BMI subgroups. CONCLUSION: Oral, ultra-low-dose continuous combined E0.5 mg/D2.5 mg and low-dose continuous combined E1 mg/D5 mg alleviated postmenopausal VMS compared with placebo, irrespective of BMI.

Ultra-low-dose estradiol and dydrogesterone for treatment of vasomotor symptoms in Europe and China.

OBJECTIVE: Among postmenopausal women, oral, ultra-low-dose continuous combined estradiol (E0.5 mg) plus dydrogesterone (D2.5 mg) reduces vasomotor symptoms (VMS). METHODS: This study was a post hoc analysis of data from two phase 3, double-blind studies. Postmenopausal women were randomized 2:1:2 to receive E0.5 mg/D2.5 mg, E1 mg/D5 mg (not included in this analysis) or placebo for 13 weeks (European study), or randomized 1:1 to receive E0.5 mg/D2.5 mg or placebo for 12 weeks (Chinese study). Endpoints assessed in ethnicity subgroups (European and Chinese) included changes from baseline in number of hot flushes, number of moderate-to-severe hot flushes and Menopause Rating Scale (MRS) score. RESULTS: Overall, 579 women were included in the analysis (E0.5 mg/D2.5 mg, n = 288; placebo, n = 291). European and Chinese women receiving E0.5 mg/D2.5 mg experienced greater reductions from baseline in mean daily number of hot flushes and mean daily number of moderate-to-severe hot flushes at week 4, week 8 and end of treatment versus those receiving placebo. Significant improvements in the 'hot flushes, sweating' MRS item score were reported in both European and Chinese women. CONCLUSION: Oral, ultra-low-dose continuous combined 0.5 mg 17ß-estradiol and 2.5 mg dydrogesterone improved VMS compared with placebo in European and Chinese postmenopausal women, with a positive impact on health-related quality of life.

Ultra-low-dose continuous combined estradiol and dydrogesterone in postmenopausal women: A pooled safety and tolerability analysis.

Objective: To assess the safety and tolerability of ultra-low dose estradiol and dydrogesterone (E0.5 mg/D2.5 mg) among postmenopausal women. Methods: This pooled analysis of data from three clinical studies assessed the effects of continuous combined ultra-low-dose estradiol and dydrogesterone among postmenopausal women. Participants received E0.5 mg/D2.5 mg or placebo for 13 weeks (double-blind, randomized, European study), E0.5 mg/D2.5 mg or placebo for 12 weeks (double-blind, randomized, Chinese study), or E0.5 mg/D2.5 mg for 52 weeks (open-label, European study). Safety outcomes included treatment-emergent adverse events (TEAEs), treatment-emergent serious adverse events (TESAEs), treatment discontinuation due to a TEAE, and adverse events of special interest (AESIs). Results: Overall, 1027 women were included in the pooled analysis (E0.5 mg/D2.5 mg, n = 736; placebo, n = 291). Mean treatment exposure was 288.9 days in the E0.5 mg/D2.5 mg group and 86.6 days in the placebo group. The proportion of women experiencing ≥1 TEAE was similar in the E0.5 mg/D2.5 mg and placebo groups (50.1% vs 49.5%, respectively). TESAEs occurred in 12 (1.6%) women receiving E0.5 mg/D2.5 mg and 9 (3.1%) women receiving placebo. Discontinuation of study treatment was infrequent in both groups (E0.5 mg/D2.5 mg: 1.5%; placebo: 2.4%). The occurrence of breast pain was more common in the E0.5 mg/D2.5 mg group than in the placebo group (2.0% vs 0.3%) as was uterine hemorrhage (6.5% vs 2.4%). The incidence of acne, hypertrichoses and weight increased was similar between groups. Conclusions: Across three studies, ultra-low-dose estradiol plus dydrogesterone was well tolerated among postmenopausal women, with no increase in TEAEs or TESAEs compared with placebo.

Cardiovascular health after menopause transition, pregnancy disorders, and other gynaecologic conditions: a consensus document from European cardiologists, gynaecologists, and endocrinologists.

Women undergo important changes in sex hormones throughout their lifetime that can impact cardiovascular disease risk. Whereas the traditional cardiovascular risk factors dominate in older age, there are several female-specific risk factors and inflammatory risk variables that influence a woman's risk at younger and middle age. Hypertensive pregnancy disorders and gestational diabetes are associated with a higher risk in younger women. Menopause transition has an additional adverse effect to ageing that may demand specific attention to ensure optimal cardiovascular risk profile and quality of life. In this position paper, we provide an update of gynaecological and obstetric conditions that interact with cardiovascular risk in women. Practice points for clinical use are given according to the latest standards from various related disciplines (Figure 1).

Effects of tibolone or continuous combined oestradiol and norethisterone acetate on lipids, high-density lipoprotein subfractions and apolipoproteins in postmenopausal women in a two-year, randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To compare the effects of (a) tibolone, (b) continuous combined oestrogen plus progestogen and (c) placebo on plasma lipid and lipoprotein markers of cardiovascular risk in healthy postmenopausal women. STUDY DESIGN: Randomized, single-centre, placebo-controlled, double-blind study. PATIENTS: One hundred and one postmenopausal women were randomized (1:1:1) into one of three groups taking daily 2.5 mg tibolone, continuous oral oestradiol-17ß 2 mg plus norethisterone acetate 1 mg daily (E2 /NETA) or placebo. MAIN OUTCOME MEASURES: Fasting serum lipid, lipoprotein and apolipoprotein concentrations measured at baseline and after 6, 12 and 24 months of treatment. RESULTS: Both tibolone and E2 /NETA lowered plasma total cholesterol concentrations relative to placebo. With tibolone, high-density lipoprotein cholesterol (HDL-C) was reduced (-27% at 24 months, P < .001), the greatest effect being in the cholesterol-enriched HDL2 subfraction (-40%, P < .001). Tibolone's effect on HDL concentrations was also apparent in the principal HDL protein component, apolipoprotein AI (-29% at 24 months, P < .001). However, there was no significant effect of tibolone on low-density or very low-density lipoprotein cholesterol (LDL-C and VLDL-C, respectively). By contrast, the greatest reduction in cholesterol with E2 /NETA was in LDL-C (-22% at 24 months, P = .008). E2 /NETA reduced HDL-C to a lesser extent than tibolone (-12% at 24 months, P < .001). Effects on HDL apolipoproteins were similarly diminished relative to tibolone. E2 /NETA had no effect on VLDL-C or on the protein component of LDL, apolipoprotein B. CONCLUSION: Tibolone reduces serum HDL. E2 /NETA reduces LDL cholesterol but not apolipoprotein B, suggesting decreased cholesterol loading of LDL. Any impact these changes may have on CVD risk needs further investigation.

Independent relationships between bone mineral density, regional body fat and insulin sensitivity in white males.

BACKGROUND: Adiposity and insulin sensitivity may affect bone mineral density (BMD), but the confounding effect of weight hinders discrimination of independent associations. We explored whether regional fat masses and insulin sensitivity are independently related to BMD. MATERIALS AND METHODS: Relationships between total and regional body fat, insulin sensitivity and measures of BMD in 8 different regions were evaluated in a cross section of 590 generally healthy, white males, 274 of whom received measurement of insulin sensitivity (Si) using the intravenous glucose tolerance test. Measurements included total, android and gynoid fat and lean body mass and regional BMDs by dual-energy X-ray absorptiometry. Linear regression analyses were combined in a mediation analysis to explore associations with each regional BMD. RESULTS: Weight correlated positively with total fat mass (R2  = 0.67, P < 0.001) and negatively with Si (R2  = 0.14, P < 0.001). Body composition measures were consistently positively related to BMD in all regions except lumbar and thoracic spine. Accounting for body weight rendered negative majority of associations between total and regional fat masses and BMDs. An independent association between android fat and spine BMD was particularly apparent. Si was positively associated with total and limb BMD (P < 0.01) specifically among exercisers. Accounting for Si diminished the associations of total fat (negative) and lean body mass (positive) with total and limb BMD. CONCLUSION: Android fat is independently negatively associated with spine BMD. Among those taking exercise, increased insulin sensitivity is associated with higher limb BMD and may underlie positive associations between lean body mass and BMD.

Effects of gender, age and menopausal status on serum apolipoprotein concentrations.

OBJECTIVE: To undertake a comprehensive evaluation of apolipoprotein risk markers for cardiovascular disease (CVD) according to gender, age and menopausal status. DESIGN: Cross-sectional analysis of independent associations of gender, age and menopause with serum apolipoproteins. PARTICIPANTS: Apparently healthy Caucasian premenopausal (n = 109) and postmenopausal (n = 252) women not taking oral contraceptives or hormone replacement, and Caucasian men (n = 307). MEASUREMENTS: Serum apolipoprotein (apo) B, A-I and A-II concentrations were measured, plus serum total cholesterol, low-density and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), triglycerides, cholesterol in HDL subfractions and the apoB/apoA-I, LDL-C/apoB, HDL-C/apoA-I and HDL-C/apoA-II ratios. Analyses were undertaken with and without standardization for confounding characteristics and in 5-year age ranges. RESULTS: Overall, apoB concentrations were highest in men but in women rose with age and menopause to converge, in the age range of 50-55 years, with concentrations in men. The LDL-C/apoB ratio was generally higher in women than in men. ApoA-I concentrations were highest in postmenopausal women and lowest in men (standardized median (IQR) 144 (130, 158) vs 119 (108, 132) g/l, respectively, P < 0·001). ApoA-II concentrations were also highest in postmenopausal women but were lowest in premenopausal women (40·3 (37·5, 44·5) vs 32·9 (30·5, 35·7) g/l, respectively, P < 0·001). Nevertheless, postmenopausal women had HDL-C/apoA-I and HDL-C/apoA-II ratios approaching the lowest ratios, which were seen in men. CONCLUSIONS: Consistent with adverse effects on CVD risk, male gender, ageing in women and menopause were associated with increased apoB concentrations, and menopause and male gender were associated with a decreased cholesterol content of HDL particles.

Lipoprotein(a) in postmenopausal women: assessment of cardiovascular risk and therapeutic options.

INTRODUCTION: Lipoprotein(a) [Lp(a)], a low-density lipoprotein (LDL)-like particle, has been independently associated with increased cardiovascular disease (CVD) risk in various populations, such as postmenopausal women. The purpose of this narrative review is to present current data on the role of Lp(a) in augmenting CVD risk in postmenopausal women and focus on the available therapeutic strategies. METHODS: PubMed was searched for English language publications until November 2015 under the following terms: "therapy" OR "treatment" AND ["lipoprotein (a)" OR "Lp(a)"] AND ("postmenopausal women" OR "menopausal women" OR "menopause"). RESULTS: Only hormone replacement therapy (mainly oral estrogens) and tibolone have been specifically studied in postmenopausal women and can reduce Lp(a) concentrations by up to 44%, although evidence indicating a concomitant reduction in CVD risk associated with Lp(a) is lacking. As alternative treatments for women who cannot, or will not, take hormonal therapies, niacin and the upcoming proprotein convertase subtilisin / kexin type 9 (PCSK-9) inhibitors are effective in reducing Lp(a) concentrations by up to 30%. Statins have minimal or no effect on Lp(a). However, data for these and other promising Lp(a)-lowering therapies including mipomersen, lomitapide, cholesterol-ester-transfer protein inhibitors and eprotirome are derived from studies in the general, mainly high CVD risk, population, and include only subpopulations of postmenopausal women. CONCLUSIONS: Past, present and emerging therapies can reduce Lp(a) concentrations to a varying extent. Overall, it remains to be proven whether the aforementioned reductions in Lp(a) by these therapeutic options are translated into CVD risk reduction in postmenopausal women.

Cardiovascular health and the menopause, metabolic health.

Estrogen depletion following menopause predisposes to increased risk of cardiovascular disease (CVD), mainly due to ischemic heart disease. This is mostly evident in cases with premature menopause. The pathophysiological basis for this atherosclerotic process is the accumulation of several risk factors, such as abdominal obesity, atherogenic dyslipidemia, insulin resistance and arterial hypertension. The presence of vasomotor symptoms may further augment this risk, especially in women younger than 60 years. Menopausal hormone therapy (MHT) exerts many beneficial effects on lipid profile and glucose homeostasis as well as direct arterial effects, and may reduce CVD risk if initiated promptly (i.e.,<60 years or within ten years of the final menstrual period). Transdermal estradiol and micronized progesterone or dydrogesterone are the safest regimens in terms of venous thromboembolic events (VTE) and breast cancer risk. In any case, an individualized approach, taking into account the patient's total CVD, VTE and breast cancer risk, is recommended.

Ultra-low dose estradiol and dydrogesterone for the treatment of menopausal symptoms in a pooled, multi-ethnic population.

OBJECTIVES: Evidence suggests ethnicity-specific differences in postmenopausal symptoms, highlighting the need for therapies that are efficacious across different ethnicities. We evaluated the efficacy of an ultra-low dose combination of 0.5 mg estradiol and 0.25 mg dydrogesterone (E 0.5 mg/D 2.5 mg) in alleviating vasomotor symptoms across a multi-ethnic population. STUDY DESIGN: Data from two controlled trials were pooled to form a dataset of 583 postmenopausal women from across Europe and China. Participants were randomized to receive treatment with E 0.5 mg/D 2.5 mg or placebo for 12 weeks. MAIN OUTCOME MEASURES: The main efficacy variable was absolute change in the number of hot flushes from baseline to end of treatment. Health-related quality of life and safety were also assessed. RESULTS: Change in the number of hot flushes per day was greater with E 0.5 mg/D 2.5 mg versus placebo (mean difference - 1.5, 95 % confidence interval - 2.1, -1.0; p < 0.001). Participants treated with E 0.5 mg/D 2.5 mg reported improvement in health-related quality of life (including psychological symptoms, vaginal dryness), and high amenorrhea rates. Combined E 0.5 mg/D 2.5 mg was well tolerated: there were no differences between groups in the percentage of participants with at least one serious adverse event or treatment-emergent serious adverse events. Analysis of change in body weight indicated no differences between groups. CONCLUSIONS: This pooled analysis demonstrates the consistent efficacy of E 0.5 mg/D 2.5 mg in the treatment of menopause-related symptoms across a multi-ethnic population of postmenopausal women.

Effects of tibolone or continuous combined oestradiol/norethisterone acetate on glucose and insulin metabolism.

OBJECTIVE: To determine the effects of tibolone or oestradiol (E(2) )/norethisterone acetate (NETA) hormone replacement therapy on glucose and insulin metabolism in postmenopausal women. DESIGN: Single-centre double-blind placebo-controlled randomized clinical trial. SUBJECTS/METHODS: We randomized 105 healthy postmenopausal women to tibolone 2·5 mg daily, continuous combined oral E(2) 2 mg/NETA 1 mg daily or placebo over a 2-year study. We performed intravenous glucose tolerance tests (IVGTT) with measurements of plasma glucose, insulin and C-peptide concentrations and the IVGTT glucose elimination rate, k. Mathematical modelling was performed to determine measures of insulin sensitivity, S(i) , pancreatic insulin secretion and hepatic and plasma insulin elimination. RESULTS: Tibolone decreased S(i) to 53-63% and k to 72-79% of baseline values but increased IVGTT phase 2 C-peptide concentrations 1·6-1·8-fold and pancreatic insulin secretion 2·2-2·4-fold, so overall IVGTT glucose concentrations were unaffected. Similar, but for k, significantly smaller changes in insulin and C-peptide secretion were seen with E(2) /NETA, also with no effect on overall IVGTT glucose concentrations. CONCLUSIONS: Tibolone reduces insulin sensitivity. Healthy postmenopausal women seem able to compensate for this and maintain normal postload glucose concentrations, but it may not be advisable to prescribe tibolone to women with, or at increased risk for, diabetes.

Outcomes and complications following spinous process fixation: a single-center analysis of 192 cases.

Spinous process fixation (SPF) is presented as less invasive than pedicle screws. There has been little quantitative data to support this assertion, and "minimally invasive" has not been well defined in spine surgery. Length of stay (LOS) and blood loss (BL) were chosen as surrogate measures of "minimally invasive." A chart review was conducted on 192 lumbar fusion patients (374 levels). A backward-selection multiple-linear-regression was performed to determine what variables contribute to LOS and estimated blood loss (EBL). A logistic regression controlling for age and number of levels on complication rates was also performed. Number of levels with supplementary screw fixation (SSF) was significantly associated with LOS (p = 0.003). Controlling for number of surgical levels, LOS increased by 0.30 days (95% CI: 0.02-0.58) for each level with SSF. For each additional level including SSF, BL increases by 25.31 cc (95% CI: 3.50-47.12, p = 0.023). Interbody fusion increases blood loss by 68.16 cc (95% CI: 17.18-119.13, p = .009). For each additional level with SSF, odds of perioperative complications increase by OR = 2.34 (95% CI: 1.35-4.05). Long-term complications were not affected by instrumentation. LOS and BL are increased in patients with SSF vs. SPF only. Odds of perioperative complications are increased in patients with SSF relative to those treated with SPF alone.

Recommendations on the management of fragility fracture risk in women younger than 70 years.

The risk for fragility fracture represents a problem of enormous magnitude. It is estimated that only a small fraction of women with this risk take the benefit of preventive measures. The relationship between estrogen and bone mass is well known as they are the other factors related to the risk for fracture. There are precise diagnostic methods, including a tool to diagnose the risk for fracture. Yet there continues to be an under-diagnosis, with the unrecoverable delay in instituting preventive measures. Women under the age of 70 years, being much more numerous than those older, and having risk factors, are a group in which it is essential to avoid that first fragility fracture. Today it is usual not to differentiate between the treatment and the prevention of osteoporosis since the common aim is to prevent fragility fractures. Included in this are women with osteoporosis or with low bone mass and increased risk for fracture, for whom risk factors play a primary role. There is clearly controversy over the type of treatment and its duration, especially given the possible adverse effects of long-term use. This justifies the concept of sequential treatment, even more so in women under the age of 70, since they presumably will need treatment for many years. Bone metabolism is age-dependent. In postmenopausal women under 70 years of age, the increase in bone resorption is clearly predominant, related to a sharp drop in estrogens. Thus a logical treatment is the prevention of fragility fractures by hormone replacement therapy (HRT) and, in asymptomatic women, selective estradiol receptor modulators (SERMs). Afterwards, there is a period of greater resorption, albeit less intense but continuous, when one could utilise anti-resorptive treatments such as bisphosphonates or denosumab or a dual agent like strontium ranelate. Bone formation treatment, such as parathyroid hormone (PTH), in women under 70 years will be uncommon. That is because it should be used in cases where the formation is greatly diminished and there is a high risk for fracture, something found in much older women.

Does hormone replacement therapy cause breast cancer? An application of causal principles to three studies. Part 4: the Million Women Study.

BACKGROUND: Based principally on findings in three studies, the collaborative reanalysis (CR), the Women's Health Initiative (WHI) and the Million Women Study (MWS), it is claimed that hormone replacement therapy (HRT) with estrogen plus progestogen (E+P) is now an established cause of breast cancer; the CR and MWS investigators claim that unopposed estrogen therapy (ET) also increases the risk, but to a lesser degree than does E+P. The authors have previously reviewed the findings in the CR and WHI (Parts 1-3). OBJECTIVE: To evaluate the evidence for causality in the MWS. METHODS: Using generally accepted causal criteria, in this article (Part 4) the authors evaluate the findings in the MWS for E+P and for ET. RESULTS: Despite the massive size of the MWS the findings for E+P and for ET did not adequately satisfy the criteria of time order, information bias, detection bias, confounding, statistical stability and strength of association, duration-response, internal consistency, external consistency or biological plausibility. Had detection bias resulted in the identification in women aged 50-55 years of 0.3 additional cases of breast cancer in ET users per 1000 per year, or 1.2 in E+P users, it would have nullified the apparent risks reported. CONCLUSION: HRT may or may not increase the risk of breast cancer, but the MWS did not establish that it does.

Menopause-associated risk of cardiovascular disease.

Cardiovascular disease (CVD) is of major concern in women entering menopause. The changing hormonal milieu predisposes them to increased CVD risk, due to a constellation of risk factors, such as visceral obesity, atherogenic dyslipidemia, dysregulation in glucose homeostasis, non-alcoholic fatty liver disease and arterial hypertension. However, an independent association of menopause per se with increased risk of CVD events has only been proven for early menopause (<45 years). Menopausal hormone therapy (MHT) ameliorates most of the CVD risk factors mentioned above. Transdermal estrogens are the preferable regimen, since they do not increase triglyceride concentrations and they are not associated with increased risk of venous thromboembolic events (VTE). Although administration of MHT should be considered on an individual basis, MHT may reduce CVD morbidity and mortality, if commenced during the early postmenopausal period (<60 years or within ten years since the last menstrual period). In women with premature ovarian insufficiency (POI), MHT should be administered at least until the average age of menopause (50-52 years). MHT is contraindicated in women with a history of VTE and is not currently recommended for the sole purpose of CVD prevention. The risk of breast cancer associated with MHT is generally low and is mainly conferred by the progestogen. Micronized progesterone and dydrogesterone are associated with lower risk compared to other progestogens.

Does hormone replacement therapy cause breast cancer? An application of causal principles to three studies: Part 1. The Collaborative Reanalysis.

BACKGROUND Concern that hormone replacement therapy (HRT) may cause breast cancer has existed since the time it was introduced, and based on evidence in three studies, the Collaborative Reanalysis (CR), the Women's Health Initiative (WHI) and the Million Women Study (MWS), it is claimed that causality is now established. OBJECTIVE To evaluate the evidence for causality in the three studies. Methods Using generally accepted causal criteria, in this paper the authors begin with an evaluation of the CR. Analogous evaluations of the WHI and MWS will follow. RESULTS The findings in the CR did not adequately satisfy the criteria of time order, bias, confounding, statistical stability and strength of association, dose/duration-response, internal consistency, external consistency or biological plausibility. CONCLUSION HRT may or may not increase the risk of breast cancer, but the CR did not establish that it does.

Does hormone replacement therapy cause breast cancer? An application of causal principles to three studies: part 3. The Women's Health Initiative: unopposed estrogen.

BACKGROUND: Studies from the Women's Health Initiative have reported an increased risk of breast cancer in users of estrogen plus progestogen. Among users of estrogen alone an increased risk was not observed. OBJECTIVE: To evaluate the evidence for unopposed estrogen. METHODS: In a related article (Part 2) the authors apply generally accepted causal criteria to the findings for estrogen plus progestogen. Here (Part 3) the authors apply the criteria to the findings for unopposed estrogen, as reported in a clinical trial, and in combined data from the trial and an observational study. RESULTS: In the clinical trial, after 7.1 years of follow-up the relative risk (RR) of invasive breast cancer for women assigned to estrogen was 0.77 in an 'intention-to-treat' analysis (95% CI 0.59-1.01) and 0.67 (95% CI 0.47-0.97) in an 'as treated' analysis; after 10.7 years the risk reduction persisted. Time order was correctly specified; detection bias was minimal; in the 'as treated' analysis confounding was unlikely; duration-response and internal consistency could be evaluated only to a limited extent because of scanty data; the findings were discordant with increased risks observed in the Collaborative Reanalysis and the Million Women Study; biological plausibility could not be assessed. In the combined analysis, among women who had previously used estrogen soon after the menopause there was no clear evidence of either a reduction or an increase in the risk of breast cancer among women assigned to estrogen during the trial, or among women who were using estrogen in the observational study when follow-up commenced. The combined analysis did not satisfy the criteria of time order, bias, confounding, statistical stability and strength of association, duration-response, and internal consistency; biological plausibility could not be assessed. CONCLUSIONS: The evidence from the clinical trial suggests that unopposed estrogen does not increase the risk of breast cancer, and may even reduce it. The latter possibility, however, is based on statistically borderline evidence.

Does hormone replacement therapy cause breast cancer? An application of causal principles to three studies: part 2. The Women's Health Initiative: estrogen plus progestogen.

BACKGROUND: Based principally on findings in three studies, the Collaborative Reanalysis (CR), the Women's Health Initiative (WHI), and the Million Women Study (MWS), it is claimed that combined hormone replacement therapy (HRT) with estrogen plus progestogen is now an established cause of breast cancer. For unopposed estrogen therapy the evidence in the three studies is conflicting: the CR and MWS have reported increased risks in estrogen users, while the WHI has not. The authors have previously reviewed the findings in the CR (Part 1). OBJECTIVE: To evaluate the evidence for causality in the WHI studies. METHODS: Using generally accepted causal criteria, in this paper (Part 2) the authors evaluate the findings in the WHI for estrogen plus progestogen; in a related paper (Part 3) the authors evaluate the findings for unopposed estrogen. An evaluation of the MWS (Part 4), and of trends in breast cancer incidence following publication of the WHI findings in 2002 (Part 5) will follow. RESULTS: For estrogen plus progestogen the findings did not adequately satisfy the criteria of bias, confounding, statistical stability and strength of association, duration-response, internal consistency, external consistency or biological plausibility. CONCLUSION: HRT with estrogen plus progestogen may or may not increase the risk of breast cancer, but the WHI did not establish that it does.

Efficacy and safety of a low-dose continuous combined hormone replacement therapy with 0.5 mg 17ß-estradiol and 2.5 mg dydrogesterone in subgroups of postmenopausal women with vasomotor symptoms.

OBJECTIVES: Various combinations of estrogens and progestogens are available for menopausal hormone therapy that differ in their efficacy and safety profile. We evaluated the efficacy and long-term safety of low-dose estradiol (0.5 mg) / dydrogesterone (2.5 mg) in subgroups of postmenopausal women with vasomotor symptoms. ANALYSIS: Efficacy analysis was performed on data from 2 previously published studies for subgroups defined by age, duration of menopause, and body mass index at baseline. The primary efficacy variable was the number of moderate to severe hot flushes from baseline to week 13. Long-term safety was evaluated in relation to age and duration of menopause. Safety variables included adverse events to week 52 and change from baseline to endpoint in laboratory and vital sign values. RESULTS: The treatment difference seen in the overall population in favour of low-dose estradiol/dydrogesterone was also observed in the subgroups of patients aged 45 to < 55 years (p < 0.01) and ≥55 years (p < 0.05), with menopause duration of >12 months to <60 months (p < 0.05) and ≥ 60 months (p < 0.005), and with a BMI at baseline of <25 kg/m2 (p < 0.05) and 25 to <30 kg/m2 (p < 0.01). Low-dose estradilol/dydrogesterone was well tolerated across the different subgroups. The incidence of breast-related adverse events was very low. No breast malignancy was reported. Only one adverse endometrial outcome of simple hyperplasia was observed. CONCLUSION: The results of our analyses confirmed the consistent treatment effect on vasomotor symptoms and the favourable safety profile of 0.5 mg 17ß estradiol and 2.5 mg dydrogesterone in different patient subgroups.