Continuous Combined Estrogen-progestin Therapy Research Articles

Continuation of postmenopausal hormone replacement therapy: comparison of cyclic versus continuous combined schedules.

Discontinuation of hormone replacement therapy (HRT) is much more common than what is reported in randomized, double-blind clinical trials. Our purpose in this retrospective study, using a prescription database, was to compare the continuation rate among women who took cyclic combination therapy adding progesterone to estrogen (CYC-PERT) or continuous combined estrogen progestin therapy (CC-PERT). The study subjects were 1,532 women, ≥45 years old, who initially filled index prescriptions for 0.625 mg conjugated estrogens. They were divided into two groups (CYC-PERT = 644, CC-PERT = 888) on the basis of coprescribed medroxyprogesterone. We found that for all women initiating therapy, 35-40% did not return for a refill and 76-81% stopped therapy within 3 years. Those prescribed CC-PERT initially were more likely to stop than those prescribed CYC-PERT (rate ratio [RR] = 1.20; 95% confidence interval [CI] = 1.06-1.35). Adjustments for age, year of starting medication, cost of medication, and prescriber specialty did not affect the difference in discontinuation between the two regimens (RR 1.18, 95% CI = 1.04-1.34). We conclude that the likelihood of women continuing HRT beyond 3 years of initiation is low. Furthermore, compared with CYC-PERT users, those receiving CC-PERT have a slightly higher probability of discontinuation. Efforts should be made to understand why three quarters of women beginning HRT will stop it long before it can provide major long-term benefit.

Incidence of endometrial spotting or bleeding during continuous-combined estrogen-progestin therapy in postmenopausal women with and without hypertension.

Endometrial spotting or bleeding is a common adverse effect among women taking continuous-combined estrogen-progestin therapy. The renin-angiotensin-aldosterone system plays a major role in hypertension and is present in the endometrium. We hypothesized that postmenopausal women with hypertension would have a higher incidence of bleeding compared with postmenopausal women without hypertension. A multivariate mixed-effects logistic model estimated the odds ratios for the relationship of hypertension status or use of antihypertensive drugs with endometrial bleeding using the Women's Health Initiative database. The incidence of spotting or bleeding in the first 12 months of estrogen-progestin use was 42% in women aged 50 to 79 years. Women with hypertension were more likely to experience bleeding than women without hypertension (odds ratio, 1.07; 95% CI, 1.02-1.13). Overall antihypertensive medication use increased bleeding with an odds ratio of 1.24, whereas angiotensin II receptor antagonists had a reduced odds ratio (0.53). Postmenopausal women with hypertension are more likely to bleed than postmenopausal women without hypertension when taking continuous estrogen-progestin, with less bleeding in women using angiotensin II receptor antagonists. This finding is novel and supports our hypothesis that the endometrial renin-angiotensin-aldosterone system may contribute to endometrial bleeding.

Cancer of the corpus uteri.

Cancer of the corpus uteri.

Differential effects of menopausal therapies on the endometrium

Currently available treatments for menopausal symptoms are associated with differing endometrial safety and endometrium-related tolerability profiles. This article reviews the differential endometrial effects associated with estrogen therapy, estrogen-progestin therapy (EPT), selective estrogen receptor modulators (SERMs), and tissue-selective estrogen complex (TSEC). Searches of electronic databases and of recent presentations at congresses were performed. Articles and abstracts relevant to the endometrial effects of estrogen therapy, EPT, SERMs, and TSECs were summarized in this interpretive literature review. Owing to their effects on the endometrium, cyclic and continuous-combined EPT can induce irregular uterine bleeding. Cyclic EPT may induce endometrial proliferation. Continuous-combined EPT reduces the incidence of endometrial cancer. In the endometrium, SERM activity ranges from essentially neutral to agonist, depending on the individual SERM. Raloxifene, tamoxifen, lasofoxifene, ospemifene, and bazedoxifene (BZA) demonstrated different degrees of endometrial tissue effects in preclinical and clinical studies. BZA inhibits the effects of conjugated estrogens on the endometrium. These effects are attributable to tissue-specific estrogen receptor degradation, which effectively diminishes the molecular target of estrogen activity in the endometrium. Conjugated estrogens/BZA, a TSEC, has a favorable endometrial profile, with incidences of hyperplasia and bleeding/spotting similar to those of placebo. Endometrial safety is a significant hurdle in the development of new hormone therapies for postmenopausal women. Preclinical and clinical findings suggest that BZA has an endometrial profile distinct from those of other SERMs. TSECs are a novel approach to providing relief of menopausal symptoms with adequate endometrial safety profile.

Long-term use of continuous-combined estrogen-progestin hormone therapy and risk of endometrial cancer

The daily administered dose of progestin in continuous-combined estrogen-progestin therapy is provided to counteract the proliferative effect of estrogen on the postmenopausal endometrium. However, there remains some uncertainty as to whether use of such a combined regimen, over the long term, is associated with an altered risk of endometrial cancer. We pooled data from four population-based case-control studies of endometrial cancer in western Washington State. Cases, ages 45-74, were diagnosed between 1985 and 2005. Using logistic regression with the adjustment for confounding factors, women who had exclusively used continuous-combined estrogen-progestin therapy (90 endometrial cancer cases, 227 controls) were compared with women who had never used any type of hormone therapy (774 cases, 1,116 controls). Associations with duration and recency of use were evaluated overall and within strata defined by body mass index. Long-term use of continuous-combined estrogen-progestin therapy (≥10years) was associated with a reduced risk of endometrial cancer (OR=0.37, 95% CI: 0.21-0.66). This association was most pronounced in women with a body mass index ≥30kg/m(2) (OR=0.19, 95% CI: 0.05-0.68). Associations did not differ according to recency of use. These results suggest that long duration of use of continuous-combined estrogen-progestin therapy is associated with a reduced risk of endometrial cancer.

Menopausal Hormone Therapy and Subsequent Risk of Specific Invasive Breast Cancer Subtypes in the California Teachers Study

Although it is well established that combined estrogen-progestin therapy (EPT) increases breast cancer risk, questions remain regarding the effect of different formulations of hormones, whether certain women are at particularly high risk, and whether risk varies by tumor subtype. We investigated hormone therapy (HT) use in relation to breast cancer risk in the California Teachers Study cohort; after a mean follow-up of 9.8 years, 2,857 invasive breast cancers were diagnosed. Compared with women who had never used HT, women who reported 15 or more years of estrogen therapy (ET) use had a 19% greater risk of breast cancer (95% confidence interval, 1.03-1.37), whereas women using EPT for 15 or more years had an 83% greater risk (95% confidence interval, 1.48-2.26). Breast cancer risk was highest among women using continuous combined EPT regimens. Risks associated with EPT and ET use were increased with duration of HT use for women with a body mass index (BMI) of <29.9 kg/m(2) but not for women with BMI of >or=30 kg/m(2). Elevated risks associated with EPT and ET use were confined to tumors that were positive for both estrogen and progesterone receptors and those that were HER2+ but were slightly diminished for HER2- tumors. Breast cancer risks increased with longer duration of ET and EPT use, and risks were highest for continuous-combined EPT use. Furthermore, risks varied by BMI and tumor subtype. These findings underscore the need for personalized risk-benefit discussions with women contemplating HT use.

A 5-year study on the effect of hormone therapy, tibolone and raloxifene on vaginal bleeding and endometrial thickness

Objectives To study the effect of standard and low-dose estrogen–progestin therapy (EPT), tibolone and raloxifene on the incidence of vaginal spotting/bleeding and endometrial thickness over a 5-year period. Methods Seven hundred eighty-six postmenopausal women were studied in an open prospective design. Vaginal spotting/bleeding and endometrial thickness as assessed by transvaginal ultrasonography was compared between six categories of women over a 5-year period: three categories in women on continuous combined estrogen–progestin therapy, one category under tibolone, one category under raloxifene and one under no treatment. More specifically, women received tibolone 2.5 mg ( N = 204), raloxifene HCl 60 mg ( N = 137), conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5 mg ( N = 122), 17β-estradiol 2 mg/norethisterone acetate 1 mg ( N = 58), 17β-estradiol 1 mg/norethisterone acetate 0.5 mg ( N = 76) or no therapy (controls, N = 189). Women with suspected endometrial pathology were referred for hysteroscopy. Results Bleeding/spotting incidence was highest among standard dose EPT users (conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5 mg: 40.1%, 17β-estradiol 2 mg/norethisterone acetate 1 mg: 44.8%, p < 0.001 compared to controls). Low-dose EPT associated with lower incidence of spotting/bleeding (34.1%). The incidence under tibolone and raloxifene was 22.5% and 2.9%, respectively, while 3.2% of women not receiving therapy reported vaginal spotting/bleeding. Mean endometrial thickness was not significantly affected in any of the groups studied. The drop-out rate due to spotting/bleeding was higher in the two higher dose EPT regimens. After logistic regression analysis, age at baseline was the only significant predictor of subsequent spotting/bleeding ( b = −0.25, S.E. = 0.09, p = 0.006), while menopausal age and pre-treatment serum FSH had marginal significance. Conclusions EPT, tibolone and raloxifene do not appear to associate with significant changes in endometrial thickness in the majority of cases. The low-dose EPT regimen associated with a decreased incidence of unscheduled spotting/bleeding compared to the standard dose regimens. Tibolone expressed a favorable endometrial profile, as seen in its effect on unscheduled spotting/bleeding and mean endometrial thickness. Raloxifene associated with the lowest incidence in S/B and the lowest drop-out rate.s

Transition From Estrogen–Progestin to Raloxifene in Postmenopausal Women

To compare vasomotor symptoms after transition from estrogen-progestin therapy to raloxifene 60 mg/d with and without a placebo washout. Postmenopausal women currently taking continuous combined estrogen-progestin therapy (conjugated equine estrogen, 0.625 mg/medroxyprogesterone acetate, 2.5 or 5 mg) daily for 5 or more months were enrolled. Women were randomized to 1 of 4 blinded regimens: 1) 12 weeks estrogen-progestin; 2) 12 weeks placebo; 3) 4 weeks placebo, then 8 weeks raloxifene; or 4) 12 weeks raloxifene. For the final 36 weeks, all subjects received raloxifene. Vasomotor symptoms were assessed by patient diaries. A total of 266 women (mean age 57.5) were enrolled. Mean hot flush frequency at baseline was approximately 1 per week in the entire population, with 16% of women reporting hot flushes. Mean frequency and severity of hot flushes during the first 12 weeks of the study were statistically greater in the 3 groups transitioned off estrogen-progestin (range of hot flushes per week: 4 weeks, 11-12; 8 weeks, 18-24; 12 weeks, 13-16), as compared with those continuing estrogen-progestin, with no difference between these 3 groups (P> or =.1). Approximately 50-70% of these women reported hot flushes, generally rated as mild to moderate by participants, after estrogen-progestin discontinuation. A large proportion of women discontinuing estrogen-progestin experience hot flushes. Raloxifene does not appear to increase the frequency or severity of vasomotor symptoms in women discontinuing estrogen-progestin more than that observed with placebo treatment after estrogen-progestin discontinuation. Transition from estrogen-progestin to raloxifene with no washout period therefore may be acceptable. I

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study: design and baseline characteristics

The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) trial is a three-arm, randomized, placebo-controlled, double-blind study to determine the effect of tibolone 2.5 mg (Org OD 14) and continuous combined conjugated equine estrogens plus medroxyprogesterone acetate (0.625 mg/2.5 mg respectively) on progression of intima-media thickness of the carotid arteries and bone mineral density of the lumbar vertebrae and proximal femur in postmenopausal women. A total of 866 healthy postmenopausal women were recruited in six U.S. centers and five European centers. Duplicate carotid ultrasound examinations of the common carotid artery, the carotid bifurcation, and the internal carotid artery were performed at baseline. Single measurements of bone mineral density of the lumbar vertebrae and proximal femur were obtained at baseline. After randomization, ultrasound examinations were repeated every 6 months for 36 months following baseline, with a duplicate examination at the end of the study. Bone mineral density was measured every 12 months throughout the trial. The primary outcome is change in mean common carotid intima-media thickness (CIMT), defined as the average of the intima-media thickness measurements performed circumferentially at predefined angles for the near and far wall of 10-mm segments of the right and left distal common carotid arteries. Unique new features of the OPAL study are the specifically developed OPAL ultrasound protocol, yielding highly reproducible CIMT measurements, and the use of two experienced core laboratories for CIMT readings (one in the United States and one in Europe) with one common quality assurance and control program. The OPAL study is a large, placebo-controlled trial evaluating the effects of tibolone, as well as one of the first large randomized studies to determine the effects of continuous combined estrogen-progestin therapy on carotid atherosclerosis in healthy postmenopausal women. The OPAL study results are expected to complement other studies on atherosclerosis progression in healthy postmenopausal women.

Serum lipids and apolipoproteins in Greek postmenopausal women: association with estrogen, estrogen-progestin, tibolone and raloxifene therapy.

The aim of this study was to assess lipid and apolipoprotein levels in postmenopausal women taking various regimens of replacement therapy or no therapy. Seven hundred forty-eight postmenopausal women followed in the Menopause Clinic of the 2nd Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, were studied in a cross-sectional design. Women were either non-users of replacement therapy (no. = 511) or users of one of the following regimens: conjugated equine estrogen 0.625 mg (CEE, no. = 34), CEE 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, no. = 60), 17beta-estradiol 2 mg plus norethisterone acetate 1 mg (E2/NETA, no. = 44), tibolone 2.5 mg (no. = 84), raloxifene HCI 60 mg (no. = 51). Total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C), triglycerides (TG), apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) levels were assessed. Women were grouped according to replacement regimen and mean levels of lipid and apolipoproteins were compared between groups. Women in the raloxifene group were older and longer menopaused. After adjustment for age and duration of menopause, TG levels were significantly lower in the tibolone and E2/NETA groups (75 and 89.9 mg/dl, respectively) compared to non-users. TC was lower in all therapy groups, but the difference acquired significance only in the E2/NETA (207.8 mg/dl), compared to non-users (231.5 mg/dl). LDL-C levels were significantly lower in the CEE (133.8 mg/dl), CEE/MPA (130.4 mg/dl) and raloxifene group (129.9 mg/dl) compared to non-users (151.9 mg/dl). There was no difference in HDL-C levels between users and non-users (58.9 mg/dl) except for the tibolone group where HDL-C was significantly lower (48.6 mg/dl). ApoA1 levels were significantly higher in the CEE/MPA group (194.4 mg/dl) and significantly lower in the tibolone group (141.6 mg/dl) compared to non-users (170.4 mg/dl). No difference was detected between groups concerning ApoB levels. In conclusion, tibolone therapy is associated with lower TG levels as well as lower HDL and ApoA1 levels. ERT, continuous combined estrogen-progestin therapy (HRT) and raloxifene are associated with lower LDL-C levels. Among continuous combined HRT users, CEE/MPA is associated with higher ApoA1 levels, while E2/NETA with lower TG levels. Large prospective randomized studies are required to validate these results.

Differing effects of low-dose estrogen–progestin therapy and pravastatin in postmenopausal hypercholesterolemic women

Background: Most studies examining the potential cardioprotective effects of postmenopausal estrogen have been undertaken in healthy women, with doses that may not be appropriate for long-term intervention.New low-dose estrogen-progestin regimens alleviate postmenopausal symptoms with a favorable side-effect profile; however, little is known of the impact of such regimens in women at increased risk of cardiovasculardisease. Hence, we have evaluated the effects of low-dose oral estrogen-progestin therapy on serum lipoprotein lipids, brachial artery reactivity and fibrinogen in hypercholesterolemic postmenopausal womenin direct comparison with the effects of pravastatin, a lipid-lowering agent known to reduce cardiovascular events in women.Methods: In a randomized, double-blind, double-dummy, parallel trial,we studied the effects of continuous combined estrogen-progestin therapy (1 mg 17β-estradiol with 500 μg norethisterone acetate daily) or pravastatin (20 mg daily) in 72 postmenopausal women withfasting serum low-density lipoprotein (LDL) cholesterol levels greater than 124 mg/dl after an 8-week run-in diet, over a 24-week period. The primary end-point was percentage change in LDL cholesterol frombaseline.Results: The intention-to-treat population comprised 65 women, mean age 59 ± 6.3 years, and 29 in each group completed the trial. Diet alone reduced LDL cholesterol significantlyin both treatment groups, in association with a reduction in weight during this period. Compared with respective baseline values, pravastatin decreased LDL cholesterol and total cholesterol to a greaterextent than hormone therapy (p = 0.0001 and 0.003 for difference between treatments, respectively). High-density lipoprotein (HDL) cholesterol levels decreased with hormone therapy, but did not changewith pravastatin (p = 0.01). Lipoprotein(a) decreased significantly with hormone therapy only (-14%, 95% confidence interval (CI) -21 to -6%, p = 0.01 for difference between groups). Brachialartery flow-mediated dilatation (FMD) was impaired at baseline, and this increased with hormone therapy (absolute mean change in artery diameter as percentage units 2.07, 95% CI 0.57-3.57, p = 0.009)versus no change with pravastatin (0.19, 95% CI -1.1 to 1.5, p = 0.78), with a near-significant difference between the two groups (p = 0.058). A significant correlation between improved brachialartery FMD and reduction in LDL cholesterol was not observed. Fibrinogen decreased significantly in both treatment groups with no difference between treatments.Conclusions: In postmenopausalhypercholesterolemic women, pravastatin and hormone therapy exhibited divergent effects. The former lowered total and LDL cholesterol more effectively, whereas hormone therapy lowered lipoprotein(a) significantlyand improved brachial artery endothelium-dependent dilatation, independent of the reduction in LDL cholesterol. The modest increase in brachial artery FMD seen is consistent with hypercholesterolemia compromisingendothelial integrity, and suggests that the important effect of estrogen on the endothelial microenvironment may be attenuated in women with endothelial dysfunction.

2.P.104 Effect of continuous combined estrogen-progestin therapy on lipoprotein (a) and lipid metabolism

2.P.104 Effect of continuous combined estrogen-progestin therapy on lipoprotein (a) and lipid metabolism

Estrogen-progestin replacement therapy and endometrial cancer.

It has been known for more than 20 years that estrogen replacement therapy substantially increases a woman's risk of developing endometrial cancer. To reduce this increased risk, progestins have been added to estrogen replacement therapy for between 5 and 15 days (usually 7 or 10 days) per "month" in a sequential fashion (sequential estrogen-progestin replacement therapy) or with each dose of estrogen replacement therapy (continuous combined replacement therapy). At the present time, however, little is known about the effects of varying the number of days that progestin is used in sequential estrogen-progestin replacement therapy. We sought to determine the effects of sequential estrogen-progestin replacement therapy and continuous combined replacement therapy on a woman's risk of developing endometrial cancer. A population-based, case-control study of 833 case subjects and 791 control subjects was conducted. Women were postmenopausal, white, and aged 50-74 years when first diagnosed with invasive endometrial cancer or were aged 50-74 years at the matching date for control subjects. All subjects were interviewed in person with the aid of a month-by-month calendar. Relative risks were estimated by odds ratios (ORs); ORs were adjusted simultaneously for the different forms of hormone replacement therapy and for the known endometrial cancer risk factors. The adjusted OR was 2.17 (95% confidence interval [CI] = 1.91-2.47) per 5 years of estrogen replacement therapy use (based on 422 users among the case subjects and 262 users among the control subjects). For women who received sequential estrogen-progestin replacement therapy with the progestin given for less than 10 days (effectively 7 days) per month, the adjusted OR was only slightly reduced to 1.87 (95% CI = 1.32-2.65) per 5 years of use (74 case subjects and 47 control subjects). However, when progestin was given for 10 or more days (effectively 10 days), there was essentially no increased risk (adjusted OR = 1.07 per 5 years of use; 95% CI = 0.82-1.41) (79 case subjects and 88 control subjects). Continuous combined replacement therapy was also associated with essentially no increased risk (adjusted OR = 1.07 per 5 years of use; 95% CI = 0.80-1.43) (94 case subjects and 81 control subjects). The progestin in sequential estrogen-progestin replacement therapy needs to be given for at least 10 days to block effectively any increased risk of endometrial cancer. Continuous combined estrogen-progestin therapy is similarly effective. Neither regimen reduces a woman's underlying risk of endometrial cancer. The sharp distinction between the effects of less than 10 days (effectively 7 days) and 10 or more days (effectively 10 days) of progestin use in sequential estrogen-progestin replacement therapy suggests that the extent of endometrial sloughing may play a critical role in determining endometrial cancer risk.

Estrogen Replacement Therapy: New Options, Continuing Concerns

To the Editor. —The articles by Dr Speroff and colleagues 1 and the Writing Group for the Postmenopausal Estrogen/ Progestin Intervention (PEPI) Trial 2 address a number of relevant issues regarding postmenopausal hormone replacement therapy (HRT) and lend additional weight to the growing body of evidence that suggests that continuous combined estrogen-progestin therapy may be the optimal regimen for HRT in women with an intact uterus. The Editorial by Dr Insogna and colleagues 3 further states that the data from the Postmenopausal Estrogen/Progestin Interventions (PEPI) trial and the Continuous Hormones as Replacement Therapy (CHART) study suggest that continuous conjugated equine estrogen-medroxyprogesterone acetate (CEE-MPA) is superior to continuous norethindrone acetate—ethinyl estradiol (NA-EE 2 ) in terms of effect on lipid profile. By highlighting key findings in the 2 studies, the Editorial provides useful direction for clinical decision making. However, both the Editorial's authors and The Journal's editors appear to have ignored disturbing

Hormone replacement therapy after breast cancer and a review of the therapeutic properties of phyto-estrogens

After breast cancer, about 10% of women have severe, persistent menopausal symptoms, and could benefit from the use of hormone replacement therapy (HRT). Its use is, however, controversial for fear of stimulating tumor growth or recurrence. The effect of continuous combined estrogen-progestin therapy on tumor recurrence and mortality was investigated in a retrospective, matched case-control study. A total of 901 breast cancer patients, of whom 90 had taken estrogen, mostly in combination with progestin, were studied. The results suggest that continuous combined HRT using a moderate dose of progestin appears to be a safe form of treatment for menopausal symptoms after breast cancer.Non-HRT treatments for breast cancer-related symptoms are also considered and found to have application in a variety of situations. The nature of phyto-estrogens is briefly explained and their potential as therapy for symptoms and disease association with breast cancer explored.

Endometrial response to hormone replacement therapy as assessed by expression of insulin-like growth factor-binding protein-1 in the endometrium

To assess endometrial response to parenteral levonorgestrel in hormone replacement therapy by means of morphological criteria and immunohistochemical staining of insulin-like growth factor-binding protein-1 (IGFBP-1). Endometrial samples were collected from 35 postmenopausal women after 12 to 22 months of continuous combined estrogen-progestin therapy. All subjects were treated with parenteral progestin. A group of 8 women was treated with a subdermal levonorgestrel-releasing implant, and 27 women had a levonorgestrel-releasing intrauterine device (IUD). Sections of formalin-fixed paraffin-embedded biopsies were used for immunohistochemistry and after hematoxylin-eosin staining for routine histologic examination. Atrophic epithelium with pronounced decidual reaction in the stroma was detected by histologic examination in all endometrial samples obtained from 27 women treated with the levonorgestrel-releasing IUD. In contrast, the endometrium was proliferative in seven of eight (87.5 percent) biopsies obtained from women treated with the levonorgestrel-releasing implant. Immunoreactive IGFBP-1 was detected in decidualized stromal cells in all endometrial samples obtained during intrauterine levonorgestrel therapy, whereas only one of eight samples obtained from women treated with subdermal levonorgestrel exhibited weak staining for IGFBP-1. Our data show that both the morphological and biochemical response of post- menopausal endometrium to parenteral levonorgestrel was strikingly different, depending on the route of progestin administration, and that the decidual reaction and epithelial atrophy induced by intrauterine levonorgestrel were associated with expression IGFBP-1 in decidualized stromal cells.