Changes in the withdrawal bleeding pattern and endometrial histology during 17 beta-estradiol-dydrogesterone therapy in postmenopausal women: a 2 year prospective study

Choice of progestogen for endometrial protection in combination with transdermal estradiol in menopausal women

Transdermal estradiol (TE) application (using gels, patches or a novel spray) is now a preferred route of hormone therapy (HT) in menopausal women, because various risks such as venous thromboembolism, stroke and unwanted hepatic effects can be reduced compared with oral HT. However, in the presence of an intact uterus, concurrent administration of progestogen is needed for endometrial protection. Due to the variety of progestogens available and differences in their clinical effects, the selection of the most appropriate substance and dosing for individual combination therapy can be difficult. This is especially true for TE gels and the novel spray because no fixed combination products are commercially available, meaning all progestogens must be added separately, and even for patches only two transdermal synthetic progestogens are available. The aim of this review was to summarize data on the endometrial effects of the different progestogens and to provide practical recommendations for the choice of progestogen (type and dosing), with a focus on endometrial protection when using TE, especially when using the novel estradiol (E2) spray.

Oral estradiol and dydrogesterone combination therapy in postmenopausal women: review of efficacy and safety

HRT is known to be effective for the relief of menopausal symptoms and prevention of osteoporosis. HRT should be tailored to the woman, enhancing the beneficial effects of the treatment while minimizing the risks. It is difficult to evaluate data on particular preparations of HRT and the different dosages in isolation. The purpose of this review is to highlight the efficacy and safety specific to oral estradiol and dydrogesterone combinations of four different dose strengths. A systematic literature search using Medline was carried out to identify studies containing efficacy or safety data. The findings of the retrieved publications confirm that estradiol and dydrogesterone combinations give very effective menopausal symptom relief and prevention of osteoporosis whilst maintaining a good safety profile. Data also show that these combinations of HRT give additional benefit to certain metabolic parameters including lipids, insulin, glucose and body fat distribution. By selecting the treatment and dose most suitable for each individual woman at her particular stage of menopause, the benefits can be optimized whilst mitigating the risks. HRT plays an important role in improving and maintaining women's health when used appropriately.

Progestational effects of dydrogesterone in vitro, in vivo and on the human endometrium

Dydrogesterone has a molecular structure closely related to that of natural progesterone, but it has enhanced oral availability compared with progesterone. The hormonal profile and the progestational potency of dydrogesterone has been determined in vitro, in vivo and in humans, in combination with estrogens or without. It showed varying affinity for progesterone-binding proteins in uterine tissue in vitro, depending on the species. It exerted a clear progestational response in the rabbit in vivo, although the potency was influenced somewhat by the route of administration. When used in hormone replacement therapy, 10mg dydrogesterone given sequentially provides adequate protection against endometrial hyperplasia in postmenopausal women using 2mg estradiol. Similarly, a dydrogesterone dose of 5mg also protects the endometrium when continuously combined with 1mg estradiol. Dydrogesterone also has beneficial effects in women with amenorrhea/oligomenorrhea, dysfunctional uterine bleeding and irregular cycles. In conclusion, having a similar profile to progesterone but with better oral availability, dydrogesterone has been used successfully to treat disorders related to absolute or relative progesterone deficiency.

Cyclical dydrogesterone in secondary amenorrhea: results of a double-blind, placebo-controlled, randomized study

Secondary amenorrhea in women with normal estrogen levels increases the risk of endometrial carcinoma. Cyclical dydrogesterone induces regular withdrawal bleeding and effectively protects the endometrium of postmenopausal women receiving estrogens. In order to assess the efficacy of dydrogesterone in inducing regular withdrawal bleeds in premenopausal women with secondary amenorrhea or oligomenorrhea and normal estrogen levels, a double-blind, randomized, placebo-controlled, multicenter study was conducted in 104 women using cyclical dydrogesterone as is used for estrogen replacement therapy. Treatment consisted of dydrogesterone (10 mg/day on days 1-14 followed by placebo on days 15-28 of each cycle) given for six cycles of 28 days. The control group received placebo throughout the six cycles. Bleeding was documented by the patient on diary cards. The number of women with withdrawal bleeding during the first cycle was twice as high in the dydrogesterone group as in the placebo group (65.4% vs. 30.8%; p = 0.0004). Superiority of dydrogesterone was also observed for regularity of bleeding over the six cycles (p < 0.0001), although endometrial thickness after six cycles did not differ between the groups. In conclusion, dydrogesterone is significantly superior to placebo in inducing withdrawal bleeding, and maintaining regular bleeding, in women with secondary amenorrhea and normal estrogen levels.

Endometrial safety of hormone replacement therapy: review of literature

Unopposed estrogens for treating menopausal symptoms were extensively used when epidemiological findings associated them with an increased endometrial cancer risk. Adding progestogens reverse this side effect efficiently but patient, dose, type and especially time during which the progestogen is administered are important. Long-term uterine safety of the long cycle HRT with administration of the progestogen every 3 months remains unclear. Because regular bleeding lowers compliance, continuous combined estrogen-progestogen treatment has become popular. Many different regimens are now available using oral, transdermal, subcutaneous, intravaginal or intra-uterine application of the estrogen and/or progestogen. Available but inadequate studies seem to point towards a slightly decreased endometrial cancer risk with continuous combined preparations compared with non-HRT-users and an increased risk with long-term oral but not vaginal treatment with low-potency estrogen formulations such as estriol. Newer compounds for menopausal health such as tibolone and raloxifene seem to be safe. As for any women with abnormal vaginal bleeding, those on HRT must have an intra-uterine evaluation. Transvaginal ultrasound (TVU) is very accurate in predicting a normal uterine cavity but inaccurate in predicting endometrial pathology because of a low specificity and positive predictive value of a thick echogenic endometrium. In all such cases a three-dimensional visualisation of intra-uterine lesions is more accurate. Periodic examination with TVU and/or endometrial biopsy of HRT exposed endometrium in asymptomatic women is not cost-effective. The available limited data on the use of HRT in hysterectomised women for early stage endometrial cancer show little evidence in terms of recurrence.

Oral 17beta-estradiol (1 mg) continuously combined with dydrogesterone improves the serum lipid profile of postmenopausal women

OBJECTIVE

To investigate the effects of 1 mg 17beta-estradiol continuously combined with 2.5, 5, 10, or 20 mg dydrogesterone on the serum lipid profile of postmenopausal women.

DESIGN

Serum lipid profile was measured in two 1-year studies performed in healthy, nonhysterectomized, postmenopausal women. One study (n = 182) had an open design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 mg daily; the other study (n = 326) had a double-blind, randomized design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone at doses of 5, 10, or 20 mg daily.

RESULTS

With all four dosages of dydrogesterone, serum total and low-density lipoprotein cholesterol were significantly reduced (-4.6% to -7.6% and -6.3% to -11.6%, respectively), whereas high-density lipoprotein cholesterol was significantly increased (+4.3% to +7.4%). Serum apolipoprotein A1 and B also improved significantly, reflecting the favorable changes in high-density lipoprotein and low-density lipoprotein cholesterol, as did lipoprotein(a).

CONCLUSION

Oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 to 20 mg daily has beneficial effects on serum lipid profile in postmenopausal women.

Chlormadinone acetate versus micronized progesterone in the sequential combined hormone replacement therapy of the menopause

OBJECTIVE

The efficacy and safety of chlormadinone acetate (CA) versus micronized progesterone (P) were assessed in non-hysterectomized postmenopausal women.

MATERIALS AND METHODS

This was a multicenter, randomized, parallel group study with a 6-month double-blind period followed by a 12-month open period. Patients were randomized to receive every month during 18 months percutaneous 17 beta-estradiol (E(2)) 1.5 mg/day from Day 1 to 24 of treatment cycle, combined from Day 11 to 24 to either CA 10 mg/day (n=167) or P 200 mg/day (n=169). Endometrial biopsy (EB, main analysis criterion) was performed at baseline, and at Day 18-24 of the 6th and 18th cycles.

RESULTS

At Month 6, EB did not evidence any hyperplasia. EB were inadequate for assessment in 24.5% and 47.5% of patients in the CA and MP groups, respectively. CA was found to be as protective as P (96.3% and 92.0% of success). However, the hormonal status of the endometrium differed (P<0.001): a secretory endometrium was found in 81.5% of the CA patients, compared to 50.7% in the P group. These transformations resulted in predictable, cyclic bleeding in 94.5% of the CA patients, compared to only 62.3% of the P patients (P=0.0001). Unscheduled bleeding, spotting and/or metrorrhagia, were more frequent under P than under CA (17.9% and 13.7%, respectively). The beneficial effects on hot flushes were more important in the CA group than in the P (P<0.001). At Month 18, the biopsy and clinical results were similar to those obtained at Month 6. The safety profile, particularly the lipid one, was similar in both groups, except for drowsiness and dizziness, which were significantly more frequent under P than under CA.

CONCLUSION

The progestative effects of CA on the endometrium and on menopause-related symptoms were at least as good as those of P. Moreover, CA resulted more often than P in secretory effects, and in satisfying bleeding patterns.

Endometrial safety of continuous combined hormone replacement therapy with 17beta-oestradiol (1 or 2 mg) and dydrogesterone

OBJECTIVES

To determine the endometrial safety of oral 17beta-oestradiol combined continuously with dydrogesterone in preventing endometrial proliferation.

METHODS

The low dose group comprised three 52-week (13 cycles of 28 days) studies (two of which were double blind) using a 17beta-oestradiol dose of 1 mg daily combined with dydrogesterone 2.5, 5, 10 or 20 mg daily. The high dose group comprised two 24-week double-blind studies using a 17beta-oestradiol dose of 2 mg daily combined with dydrogesterone 2.5, 5, 10 or 15 mg daily. Endometrial safety was verified by aspiration endometrial biopsies. Inadequate progestational response was defined as proliferative endometrium, endometrial polyp, hyperplasia and carcinoma.

RESULTS

Data was evaluable from 650 healthy postmenopausal women in the low dose group and 310 in the high dose group. Endometrial protection was achieved with dydrogesterone at doses of 5 mg or higher combined with 1 or 2 mg 17beta-oestradiol. The success rate was 97%, 97% and 98% in women receiving 1/5, 1/10 and 1/20 mg, respectively, and 95%, 98% and 91% in women receiving 2/5, 2/10 and 2/15 mg, respectively. A lower success rate was achieved with the 2.5 mg dydrogesterone dosage (93% in the 1/2.5 mg group and 85% in the 2/2.5 mg group) due to more cases of proliferative endometrium. None of the women in the low dose group developed hyperplasia or carcinoma; five (0.7%) had endometrial polyps. In the high dose group, one woman given 2.5 mg dydrogesterone developed hyperplasia; there were no cases of carcinoma.

CONCLUSION

5 mg daily dydrogesterone appears to be the lowest effective dose to ensure endometrial safety in a continuous combined regimen with 1 or 2 mg 17beta-oestradiol.

Low incidence of endometrial hyperplasia with acceptable bleeding patterns in women taking sequential hormone replacement therapy with dydrogesterone

A meta-analysis was undertaken to assess the incidence of endometrial hyperplasia during sequentially combined oral 17 beta-estradiol and dydrogesterone (Femoston) treatment in postmenopausal women. Bleeding pattern was assessed separately in each study. Two studies were double-blind, 6-month studies and two were open, long-term (1- or 2-year) studies. 17 beta-estradiol 2 mg daily was combined with dydrogesterone 10 mg for 14 days per 28-day cycle. Endometrial safety was assessed by endometrial biopsy in 369 women treated. In 236 women treated for one year or more, one simple hyperplasia was diagnosed (success rate: 99.61%; lower limit of one-sided 95% confidence interval: 98.16). The last observation carried forward analysis in 369 women also revealed one simple hyperplasia (success rate: 99.73%; lower limit of one-sided 95% confidence interval: 98.72). Cyclic bleeding occurred in approximately 90% of women; the duration and day of onset was highly predictable between cycles and the severity of bleeding was generally rated as slight. In conclusion, sequentially combined 17 beta-estradiol 2 mg and dydrogesterone 10 mg has very good endometrial safety and is associated with light and predictable bleeding of short duration.

Hormonal replacement regimens and bleeding

Hormone replacement therapy may increase the quality of life of postmenopausal women. Any regimen need to offer long-term endometrial safety. It is a standard to consider the co-administration of a sequential progestogen when estrogen replacement should be initiated in non-hysterectomized women. It is almost impossible to decide which combination of an estrogen and a progestogen seems to be optimal as individual tolerance of HRT may very well limit acceptability despite metabolic benefits and proven endometrial safety of a given combination. Several combinations of oral and transdermal estradiol or conjugated equine estrogens, oral progestogens, transdermal norethisterone acetate and levonorgestrel, and intrauterine levonorgestrel may achieve endometrial safety. It is noteworthy that there is no uniform correlation between the timing of onset of bleeding induced by any sequential estrogen and progestogen replacement and a certain pattern of histology. Therefore, although it is likely, there is no absolute reassurance that regular bleeding on or after day 11 of progestogen administration rules out abnormal histopathology. Transvaginal sonography seems not to be of pivotal importance to screen asymptomatic women on replacement therapy for detection of serious abnormal endometrial findings such as hyperplasia and endometrial cancer. Continuous combined hormone replacement therapy or the use of tibolone may be an alternative in postmenopausal women, who do not want any uterine bleedings after menopause. However, spottings or bleedings most often occur at the beginning of treatment. Vaginal administration of estriol and estradiol for urogenital symptoms of estrogen deficiency may stimulate the endometrium unintentionally. Available data suggest that use of oral estriol may be associated with endometrial hyperplasia and endometrial carcinoma relatively more often compared to sequential HRT. Raloxifene, a benzothiophene derivative acting as a selective estrogen receptor modulator approved for prevention of vertebral osteoporosis, rarely causes uterine bleeding. There is no ideal therapy available to suit women looking for a permanently bleed-free hormonal replacement therapy today.

The menopause

Menopause is diagnosed after 12 months of amenorrhoea resulting from the permanent cessation of ovarian function. The mean age at menopause is 51 years. The perimenopause, a time of changing ovarian function, precedes the final menses by several years. The physiology and clinical manifestations of this transition to menopause are not well understood; however, some symptoms, such as hot flashes, certainly begin in the perimenopause. Causal associations between menopause and several symptoms and diseases are proposed. The evidence for these associations varies and is reviewed. Hormone replacement therapy can be directed at symptom relief or at prevention or treatment of chronic diseases. Doses and routes of hormone replacement therapy vary by indication. Complications of hormone replacement therapy depend on the regimen used. Knowing the expected vaginal bleeding pattern for each hormone replacement therapy regimen is important, since unexpected bleeding may signal endometrial hyperplasia. Postmenopausal hormone therapy is a complex intervention that produces positive and negative specific health effects. Overall, based on observational studies, postmenopausal women who use hormones have a 30-50% lower all-cause mortality rate than those who do not use hormones. It is important to recognise that the value that individual women place on various health outcomes associated with hormone replacement therapy may differ. Thus, the decision to use hormone replacement therapy should be made jointly by each woman and her health-care provider, after careful consideration of possible benefits, risks, and her personal preferences.

Comparison of transvaginal ultrasonography and endometrial biopsy in endometrial surveillance in postmenopausal HRT users

OBJECTIVES

To compare transvaginal ultrasonography with histological findings in endometrial evaluation of postmenopausal women using hormone replacement therapy and to evaluate endometrial safety of three hormone replacement therapy regimens.

METHODS

In a randomized, comparative study in postmenopausal women, endometrial safety was evaluated using (1) no hormone replacement therapy, (2) oral micronized 17 beta-estradiol/oral sequential dydrogesterone, (3) transdermal 17 beta-estradiol/oral sequential dydrogesterone, or (4) oral tibolone. 85 Non-hysterectomised subjects underwent transvaginal ultrasonography immediately before Pipelle biopsy at baseline and subsequently after 12 and 24 months. Endometrial thickness and uterine dimensions were determined by transvaginal ultrasonography, and endometrial thickness (double-layer) was compared with biopsy results.

RESULTS

Endometrial evaluation was conveniently performed by transvaginal ultrasonography, and endometrial thickness correlated well with biopsy findings. If endometrial thickness was < 5 mm, the endometrial biopsy sample was either inactive/atrophic or insufficient for histopathological diagnosis. Hyperplastic or malignant changes were not reported. After 24 months, endometrial thickness was increased both in the oral (P < 0.001) and transdermal (P < 0.001) 17 beta-estradiol/dydrogesterone groups, whereas with tibolone the change in endometrial thickness was not different from controls.

CONCLUSION

transvaginal ultrasonography of the endometrium reliably predicts the histological picture in hormone replacement therapy users. Using 5 mm endometrial thickness as cut-off point, more than 75% of biopsies could be avoided. All three hormone replacement therapies were safe with respect to the endometrium. With sequential 17 beta-estradiol/dydrogesterone the expected progestogen-induced secretory pattern was observed, whereas endometrial histology under tibolone closely mimicked the natural atrophic postmenopausal state.

Endometrial histology and bleeding patterns in post-menopausal women taking sequential, combined estradiol and dydrogesterone

OBJECTIVES

To determine the endometrial response and bleeding patterns in post-menopausal women who were given a sequential hormone replacement regimen with estradiol 2 mg and dydrogesterone 10 mg.

METHODS

One-hundred-and-eighty-eight (188) post-menopausal women with amenorrhea of 6 months or longer, with FSH/estradiol (E2) levels in the post-menopausal range and normal endometrium were entered in the study. All patients received a daily dose of 2 mg E2 during day 1-14 of each 28 day cycle and 2 mg E2 combined with 10 mg dydrogesterone during cycle day 15-28. The total duration of treatment was 12 months (13 cycles of 28 days).

RESULTS

The rate of adequate progestational response (secretory or atrophic) in the 146 patients who remained in the study for at least 356 days with 90% study medication compliance and received an endometrial biopsy after 13 cycles of study medication was 97.2%. Three patients had proliferative endometrium and one simple hyperplasia. Cyclic bleedings in the 153 women who remained on study medication for at least 76 days occurred in over 85% of all cycles; the day of onset occurring regularly on day 13 or 14 of the combined period; the mean duration of bleeding per cycle was approximately 5 days with most patients having (very) slight bleeding. Sixty percent of patients had no intermittent bleedings over the whole 12-month study period. The average incidence of intermittent bleeding in the remaining patients was only 2.7 and generally of very slight quantities and of short duration. Per evaluable cycle the percentage of patients with an intermittent bleeding varies from 4.6 to 9.8%. Only two patients discontinued therapy because of bleeding problems. A clear decrease in the incidence of typical menopausal symptoms, i.e. hot flushes and night sweats was observed by the first visit after 6 weeks of treatment.

CONCLUSIONS

The endometrial safety of 2 mg E2 sequentially combined with 10 mg dydrogesterone is very good as determined by the histologic response of the endometrium. The incidence of cyclic bleedings with this combination therapy is very high as is the regularity of day of onset and duration of bleeding. Blood loss during intermittent bleedings was mild and of short duration.