Bleeding patterns and endometrial histology during administration of low-dose estradiol sequentially combined with dydrogesterone

Progestogens for endometrial protection in combined menopausal hormone therapy: A systematic review

Menopausal women with an intact uterus choosing estrogens for menopausal symptom relief require a progestogen for endometrial protection. The aim of this systematic review was to evaluate the risks of endometrial hyperplasia resp. malignancy with different progestogens used in combined MHT. Overall, 84 RCTs were included. We found that 1) most studies were done with NETA, followed by MPA, MP and DYD and LNG, 2) most progestogens were only available as oral formulations, 3) the most frequently studied progestogens (oral MP, DYD, MPA, oral and transdermal NETA, transdermal LNG) were assessed in continuously as well as in sequentially combined MHT regimens, 4) FDA endometrial safety criteria were only fulfilled for some progestogen formulations, 5) most studies demonstrated endometrial protection for the progestogen dose and time period examined. However, 6) study quality varied which should be taken into account, when choosing a combined MHT, especially if off-label-use is chosen.

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.

Risks of endometrial cancer associated with different hormone replacement therapies in the E3N cohort, 1992-2008

We assessed whether different oral progestogens in hormone replacement therapy may differentially affect the risk of endometrial cancer, using data from the Etude Epidémiologique auprès de femmes de l'Education Nationale (E3N), a French cohort study (1992-2008). Hazard ratios and their confidence intervals were derived from Cox models. Among 65,630 postmenopausal women (mean follow-up: 10.8 years), 301 endometrial cancers occurred. Compared with never use, ever use of estrogen + micronized progesterone was associated with an increased risk of endometrial cancer (hazard ratio (HR) = 1.80, 95% confidence interval (CI): 1.38, 2.34) that was significantly more marked with longer duration of use (for ≤5 years, HR = 1.39 (95% CI: 0.99, 1.97); for >5 years, HR = 2.66 (95% CI: 1.87, 3.77)). Although use of estrogen + dydrogesterone was not associated overall with endometrial cancer risk (HR = 1.05, 95% CI: 0.76, 1.45), there was a significantly increased risk with long-term use compared with never use (for >5 years, HR = 1.69, 95% CI: 1.06, 2.70). Users of preparations containing other progesterone derivatives or a norsteroid derivative were not at significantly increased risk (HR = 0.79 (95% CI: 0.60, 1.05) and HR = 1.30 (95% CI: 0.85, 1.99), respectively). In conclusion, micronized progesterone and, to a lesser extent, dydrogesterone at the doses used in France may not be sufficient to prevent estrogen-induced endometrial cancers.

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.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia or carcinoma.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2012), The Cochrane Library (Issue 1, 2012), MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to January 2012) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy, sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of 12 months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals owing to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this update, 46 studies were included. Odds ratios (ORs) were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta-analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low-dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate (NETA) or 1.5 mg medroxyprogesterone acetate (MPA) is not significantly different from placebo at two years (1 mg NETA: OR 0.04; 95% confidence interval (CI) 0 to 2.8; 1.5 mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

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.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Declining circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2008), The Cochrane Library (Issue 1, 2008), MEDLINE (1966 to May 2008), EMBASE (1980 to May 2008), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to May 2008) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy and/or sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of twelve months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals due to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this substantive update, forty five studies were included. Odds ratios were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate or 1.5 mg medroxyprogesterone acetate is not significantly different from placebo (1mg NETA: OR=0.04 (0 to 2.8); 1.5mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Effects of dydrogesterone on the vascular system

Estrogens exert beneficial effects on the vascular system, while progestogens generally have a negative impact (e.g. vasoconstrictor effects on the arterial system). In contrast, dydrogesterone appears to be largely neutral in terms of biochemical markers and indirect clinical endpoints, such as blood pressure, that act as surrogate markers for vascular function. Studies on lipid and carbohydrate metabolism, which can also influence vascular function, demonstrate that the addition of dydrogesterone intensifies rather than attenuates beneficial estrogenic effects. Dydrogesterone also has largely neutral effects on hemostasis. Since there are relatively few data available on clinical parameters such as blood flow measurements, especially in women with pre-existing cardiovascular diseases, increased risks cannot be excluded for a combination of estrogen replacement with dydrogesterone. Further studies should focus on this open question since dydrogesterone, with its largely neutral properties, might be a suitable option, including for older women already at increased cardiovascular risk.

Continuous combined hormone replacement therapy with 1mg 17β-oestradiol and 5mg dydrogesterone (Femoston®-conti): Endometrial safety and bleeding profile

OBJECTIVES

The aim of the study was to confirm the endometrial safety and describe the bleeding profile of continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone in post-menopausal women.

METHODS

An open, multicentre study was carried out in 290 healthy, non-hysterectomised post-menopausal women receiving oral continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone (Femoston-conti) for 1 year. Aspiration endometrial biopsies were performed at baseline and at the end of the study; those classified as hyperplasia or malignancy were considered treatment failures.

RESULTS

Only one woman developed simple hyperplasia without atypia at the end of the study; the treatment failure rate was therefore 0.4%. Cross-sectional analysis showed that the percentage of women without bleeding increased from 71% during the first cycle to around 80% by the end of the study. Approximately 50% of the bleeding episodes occurred in the form of spotting; severe bleeding was rare and only seven women withdrew prematurely from the study due to uterine bleeding. Overall, 41% of the women were amenorrhoeic throughout the study.

CONCLUSIONS

Continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone provides excellent endometrial safety and is associated with an acceptable bleeding profile.

Hormone replacement therapy in postmenopausal women: endometrial hyperplasia and irregular bleeding

BACKGROUND

The decline in circulating oestrogen around the time of the menopause often induces unacceptable symptoms that affect the health and well being of women. Hormone replacement therapy (both unopposed oestrogen and oestrogen and progestogen combinations) is an effective treatment for these symptoms. In women with an intact uterus, unopposed oestrogen may induce endometrial stimulation and increase the risk of endometrial hyperplasia and carcinoma. The addition of progestogen reduces this risk but may cause unacceptable symptoms, bleeding and spotting which can affect adherence to therapy.

OBJECTIVES

The objective of this review is to assess which hormone replacement therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma with a low rate of abnormal vaginal bleeding.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2003), The Cochrane Library (Issue 2, 2003), MEDLINE (1966 to January 2003), EMBASE (1980 to January 2003), Current Contents (1993 to January 2003), Biological Abstracts (1969 to 2002), Social Sciences Index (1980 to January 2003), PsycINFO (1972 to February 2003) and CINAHL (1982 to January 2003). The search strategy was developed by the Cochrane Menstrual Disorder and Subfertility Group. Attempts were also made to identify trials from citation lists of review articles and drug companies were contacted for unpublished data. In most cases, the corresponding author of each included trial was contacted for additional information.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of unopposed oestrogen therapy, combined continuous oestrogen-progestogen therapy and sequential oestrogen-progestogen therapy with each other and placebo administered over a minimum treatment period of six months. Trials had to assess which regimen was the most protective against the development of endometrial hyperplasia/carcinoma and/or caused the lowest rate of irregular bleeding.

DATA COLLECTION AND ANALYSIS

Sixty RCTs were identified. Of these 23 were excluded and seven remain awaiting assessment. The reviewers assessed the thirty included studies for quality, extracted the data independently and odds ratios for dichotomous outcomes were estimated. Outcomes analysed included frequency of endometrial hyperplasia or carcinoma, frequency of irregular bleeding and unscheduled biopsies or dilation and curettage, and adherence to therapy.

MAIN RESULTS

Unopposed moderate or high dose oestrogen therapy when compared to placebo was associated with a significant increase in rates of endometrial hyperplasia with increasing rates at longer duration of treatment and follow up. Odds ratios ranged from (1 RCT; OR 5.4, 95% CI 1.4 to 20.9) for 6 months of treatment to (4 RCTs; OR 9.6, 95% CI 5.9 to 15.5) for 24 months treatment and (1 RCT; OR 15.0, 95% CI 9.3 to 27.5) for 36 months of treatment with moderate dose oestrogen (in the PEPI trial, 62% of those who took moderate dose oestrogen had some form of hyperplasia at 36 months compared to 2% of those who took placebo). Irregular bleeding and non adherence to treatment were also significantly more likely under these unopposed oestrogen regimens that increased bleeding with higher dose therapy. Although not statistically significant, there was a 3% incidence (2 RCTs) of hyperplasia in women who took low dose oestrogen compared to no incidence of hyperplasia in the placebo group. The addition of progestogens, either in continuous combined or sequential regimens, helped to reduce the risk of endometrial hyperplasia and improved adherence to therapy. At longer duration of treatment, continuous therapy was more effective than sequential therapy in reducing the risk of endometrial hyperplasia. There was evidence of a higher incidence of hyperplasia under long cycle sequential therapy (progestogen given every three months) compared to monthly sequential therapy (progestogen given every month). No increase in endometrial cancer was seen in any of t in any of the treatment groups during the duration (maximum of six years) of these trials. During the first year of therapy irregular bleeding and spotting was more likely in continuous combined therapy than sequential therapy. However, during the second year of therapy bleeding and spotting was more likely under sequential regimens.

REVIEWERS' CONCLUSIONS

There is strong and consistent evidence in this review that unopposed oestrogen therapy, at moderate and high doses, is associated with increased rates of endometrial hyperplasia, irregular bleeding and consequent non adherence to therapy. The addition of oral progestogens administered either sequentially or continuously is associated with reduced rates of hyperplasia and improved adherence to therapy. Irregular bleeding is less likely under sequential than continuous therapy during the first year of therapy but there is a suggestion that continuous therapy over long duration is more protective than sequential therapy in the prevention of endometrial hyperplasia. Hyperplasia is more likely when progestogen is given every three months in a sequential regimen compared to a monthly progestogen sequential regimen.

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.