Nomegestrol acetate, a novel progestogen for oral contraception

Meningioma in patients exposed to progestin drugs: results from a real-life screening program

PURPOSE

To report the results of systematic meningioma screening program implemented by French authorities in patients exposed to progestin therapies (cyproterone (CPA), nomegestrol (NA), and chlormadinone (CMA) acetate).

METHODS

We conducted a prospective monocentric study on patients who, between September 2018 and April 2021, underwent standardized MRI (injection of gadolinium, then a T2 axial FLAIR and a 3D-T1 gradient-echo sequence) for meningioma screening.

RESULTS

Of the 210 included patients, 15 (7.1%) had at least one meningioma; seven (7/15, 47%) had multiple meningiomas. Meningiomas were more frequent in older patients and after exposure to CPA (13/103, 13%) compared to NA (1/22, 4%) or CMA (1/85, 1%; P = 0.005). After CPA exposure, meningiomas were associated with longer treatment duration (median = 20 vs 7 years, P = 0.001) and higher cumulative dose (median = 91 g vs. 62 g, P = 0.014). Similarly, their multiplicity was associated with higher dose of CPA (median = 244 g vs 61 g, P = 0.027). Most meningiomas were ≤ 1 cm³ (44/58, 76%) and were convexity meningiomas (36/58, 62%). At diagnosis, patients were non-symptomatic, and all were managed conservatively. Among 14 patients with meningioma who stopped progestin exposure, meningioma burden decreased in 11 (79%) cases with no case of progression during MR follow-up.

CONCLUSION

Systematic MR screening in progestin-exposed patients uncovers small and multiple meningiomas, which can be managed conservatively, decreasing in size after progestin discontinuation. The high rate of meningiomas after CPA exposure reinforces the need for systematic screening. For NA and CMA, further studies are needed to identify patients most likely to benefit from screening.

Progesterone stimulates cortisol production in the maturing bovine cumulus-oocyte complex

In the bovine cumulus oophorus, 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1)-mediated cortisol production dramatically increases during the periovulatory period. This event is closely associated with increased progesterone (P4) production, implying a functional connection between these C21 steroids. In this study, we investigated the mutual regulation of P4 and cortisol production in the bovine cumulus oophorus. Bovine cumulus-oocyte complexes (COCs) were aspirated from follicles 2-5 mm in diameter and subjected to in vitro maturation (IVM) for 24 h in an M199 supplemented with fetal calf serum (FCS) and follicle-stimulating hormone (FSH). COCs were treated with trilostane (0, 0.1, 1, 10 mM), an inhibitor of P4 synthesis, RU486 (0, 0.1, 1, 10 mM), a receptor antagonist for the progesterone receptor (PR) and glucocorticoid receptor (GR), and various concentrations of a synthetic progestogen nomegestrol acetate (NA; 0, 0.001, 0.01, 0.1, 1, 10 mM) to examine effect of P4. The effects of cortisol (0, 0.1, 1, 10 mM) were also examined in the presence or absence of trilostane. Trilostane and RU486 suppressed cumulus expansion, cortisol production, and HSD11B1 but not hexose-6-phosphate dehydrogenase (H6PDH) expression. Concomitant treatment with NA reversed the effects of trilostane. Unlike NA, cortisol did not alter the antagonistic effects of trilostane on cumulus expansion and HSD11B1 expression. Cortisol did not affect P4 production or steroidogenic acute regulatory protein (STAR), cholesterol side-chain cleavage enzyme (CYP11A1), 3β-hydroxysteroid dehydrogenase type 1 (HSD3B1), and HSD11B1 expression. Collectively, these results indicate that locally produced P4 is crucial in regulating the local glucocorticoid environment through PRtg in the maturing bovine cumulus oophorus. Cortisol, however, does not appear to regulate P4 or its production.

Pharmacokinetics, metabolism and serum concentrations of progestins used in contraception

Many different forms of hormonal contraception are used by millions of women worldwide. These contraceptives differ in the dose and type of synthetic progestogenic compound (progestin) used, as well as the route of administration and whether or not they contain estrogenic compounds. There is an increasing awareness that different forms of contraception and different progestins have different side-effect profiles, in particular their cardiovascular effects, effects on reproductive cancers and susceptibility to infectious diseases. There is a need to develop new methods to suit different needs and with minimal risks, especially in under-resourced areas. This requires a better understanding of the pharmacokinetics, metabolism, serum and tissue concentrations of progestins used in contraception as well as the biological activities of progestins and their metabolites via steroid receptors. Here we review the current knowledge on these topics and identify the research gaps. We show that there is a paucity of research on most of these topics for most progestins. We find that major impediments to clear conclusions on these topics include a lack of standardized methodologies, comparisons between non-parallel clinical studies and variability of data on serum concentrations between and within studies. The latter is most likely due, at least in part, to differences in intrinsic characteristics of participants. The review highlights the importance of insight on these topics in order to provide the best contraceptive options to women with minimal risks.

Evolution of the neurosurgical management of progestin-associated meningiomas: a 23-year single-center experience

PURPOSE

The improving knowledge of interactions between meningiomas and progestin refines the management of this specific condition. We assessed the changes over time of the management of progestin-associated meningiomas.

METHODS

We retrospectively studied consecutive adult patients who had at least one meningioma in the context of progestin intake (October 1995-October 2018) in a tertiary adult Neurosurgical Center.

RESULTS

71 adult women with 125 progestin-associated meningiomas were included. The number of progestin-associated meningioma patients increased over time (0.5/year before 2008, 22.0/year after 2017). Progestin treatment was an approved indication in 27.0%. A mean of 1.7 ± 1.2 meningiomas were discovered per patient (median 1, range 1-6). Surgery was performed on 36 (28.8%) meningiomas and the histopathologic grading was WHO grade 1 in 61.1% and grade 2 in 38.9%. The conservative management of meningiomas increased over time (33.3% before 2008, 64.3% after 2017) and progestin treatment withdrawal increased over time (16.7% before 2008, 95.2% after 2017). Treatment withdrawal varied depending on the progestin derivative used (88.9% with cyproterone acetate, 84.6% with chlormadinone acetate, 28.6% with nomegestrol acetate, 66.7% with progestin derivative combination). The main reason for therapeutic management of meningiomas was the presence of clinical signs. Among the 54 meningiomas managed conservatively for which the progestin had been discontinued, MRI follow-up demonstrated a regression in 29.6%, a stability in 68.5%, and an ongoing growth in 1.9% of cases.

CONCLUSIONS

Conservative management, including progestin treatment discontinuation, has grown over time with promising results in terms of efficacy and safety.

Does Nomegestrol Acetate Plus 17β-Estradiol Oral Contraceptive Improve Endometriosis-Associated Chronic Pelvic Pain in Women?

Background: To evaluate the effects of a 24/4 regimen combined oral contraceptive (COC) containing 1.5 mg 17β-estradiol (E2) and 2.5 mg nomegestrol acetate (NOMAC) compared to on-demand nonsteroidal anti-inflammatory drugs (NSAIDs) on women affected by endometriosis-associated chronic pelvic pain (the primary end point) and their quality of life (QoL) and sexual function (the secondary end points).

Materials and Methods: Ninety-nine women on E2/NOMAC constituted the study group; and 63 women on NSAIDs constituted the control group. The visual analogic scale was used to measure the levels of pelvic pain, dysmenorrhea, and dyspareunia. To assess their QoL, sexual function, and sexual distress, the Short Form-36 (SF-36), the Female Sexual Function Index (FSFI), and the Female Sexual Distress Scale (FSDS) were used, respectively. The study included two follow-ups at 3 and 6 months.

Results: Improvement in chronic pelvic pain was observed in the study group at both the 3- and 6-month follow-ups (p < 0.001). SF-36, FSFI, and FSDS had a similar trend at the 3- and 6-month follow-ups (p < 0.001). Women on NSAIDs did not report any reduction in pain symptoms or improvement in QoL (p ≤ 0.4). However, they had a limited improvement of their FSFI and FSDS (p < 0.001). The improvement of the pain symptoms, QoL, FSFI, and FSDS, was more evident in women on E2/NOMAC than in those on NSAIDs, when the study group and control group values were compared at the 3- and 6-month follow-ups (p < 0.001).

Conclusions: Women on E2/NOMAC COC showed a better reduction of endometriosis-associated chronic pelvic pain and an improvement of their QoL and sexual activity than those of the women on NSAIDs.

The effectiveness of quick starting oral contraception containing nomegestrol acetate and 17-β estradiol on ovulation inhibition: A randomized controlled trial

To determine the effectiveness of quick starting combined oral contraception (COC) contain 2.5 mg nomegestrol acetate and 1.5 mg estradiol (NOMAC/E2) comparing with 0.075 mg gestodene and 0.02 mg ethinyl estradiol (GS/EE) on ovarian ovulation inhibition rate, we conducted a non-inferiority randomized controlled trial involving 69 healthy female volunteers aged 18–40 years who had normal menstrual history and were randomized at a 2:1 ratio to take one pack of COC containing either NOMAC/E2 (study group) or GS/EE (control group) starting on menstrual cycle Day7–9. The ovarian activity was assessed by using Hoogland and Skouby grading. Forty-six and 23 participants were randomized to NOMAC/E2 and GS/EE groups, respectively. Baseline characteristics were similar between groups. No significant difference was observed between the study and control groups for ovulation inhibition rate (93.4% vs. 95.6%, risk difference: –2.2%, 95% CI: –13.1, 8.8), ovarian quiescence rate (91.2% vs. 91.2%, P = 1.000), persistent cyst rate (2.2% vs. 4.4%, P = 1.000), and ovulation rate (6.6% vs. 4.4%, P = 1.000). Quick starting COC during day7–9 of menstrual cycle can inhibit ovulation for more than 90%. The quick starting NOMAC/E2 is non-inferior to GS/EE for preventing ovulation and suppressing follicular growth.

The crystal structure of 6-methyl-3,20-dioxo-19-norpregna-4,6-dien-17-yl acetate–2,4-dihydroxybenzoic acid (1/1), C30H36O8

C30H36O8, monoclinic, P21 (no. 4), a = 10.899(2) Å, b = 11.002(2) Å, c = 11.847(2) Å, V = 1310.3(5) Å3, Z = 2, R gt(F) = 0.0504, wR ref(F 2) = 0.1161, T = 163(2) K.

Glucocorticoid and progesterone mechanisms in photoreceptor survival

Death of retinal photoreceptors is the basis of prevalent blinding diseases. Since steroids might have a therapeutic role in retinal degenerations, we compared the protective effects of dexamethasone and progesterone on photoreceptor death induced by mifepristone and light exposure. Therefore, we studied the effective protection doses for each steroid in the two models. In addition, we analyzed changes in the levels of pro- and antiapoptotic molecules, glucocorticoid receptors α and β (GRα and GRβ), and rhodopsin under conditions of successful protection and photoreceptor survival. Mifepristone and light exposure selectively damaged photoreceptors. In light exposed retinas, photoreceptors mainly disappeared in the dorsotemporal region, while mifepristone produced a uniform damage. Dexamethasone and progesterone, at the same dose of 4 mg/kg/day for 2 days, preserved over 88% photoreceptor nuclei in both models. Assessment of cell death regulators showed that, in control retinas, both steroids activated BCL-X_L, a prosurvival molecule, and decreased BID, a proapoptotic regulator. After steroid treatment of damaged retinas, BCL-X_L, BCL2 and BAX showed characteristic patterns depending on the use of dexamethasone or progesterone on mifepristone or light exposed retinas. By contrast, BID decreased with any injury-steroid combination. Changes in GRα or GRβ levels did not correlate with survival but were consistent with a mechanism of ligand induced downregulation of receptor expression. GRβ might be upregulated by progesterone. Both dexamethasone and progesterone increased retinal rhodopsin stores, suggesting a link between photoreceptor protection and transduction pathways. Results show that dexamethasone and progesterone induced comparable but not identical protection responses in each model.

Spontaneous regression of meningiomas after interruption of nomegestrol acetate: a series of three patients

BACKGROUND

The relationship between increased meningioma incidence and growth and long-term hormonal therapy with cyproterone acetate (CPA) in women has been recently established in literature. Following the raise in awareness from hormonal treatment, we describe a potential relationship between the progesterone agonist nomegestrol acetate (NOMAC) and meningioma growth.

METHODS

After implementation of a screening protocol to detect potential interactions between hormonal exposure and occurrence of meningioma, we identified patients taking NOMAC and newly diagnosed with a meningioma. NOMAC was stopped and those patients were followed tightly both clinically and radiologically. Retrospective volumetric analysis of the tumors was performed on the imaging.

RESULTS

Three patients were identified for the study. After cessation of the NOMAC, tumor shrinkage was documented for all meningiomas within the first month. Up to 70% of tumor volume reduction was observed during the first year of follow-up in one of them. None of the patients developed new symptoms.

CONCLUSION

We report the first cases of meningiomas responsiveness to discontinuation of hormonal therapy with NOMAC. Similarly to cases associated with long-term CPA intake, tumor reduction, and improvement of clinical symptoms can be observed after cessation of NOMAC.

Combined hormonal influence of cyproterone acetate and nomegestrol acetate on meningioma: a case report

Cyproterone acetate (CPA) is an antiandrogenic drug which has recently been recognized to promote the occurrence and growth of intracranial meningiomas. Nomegestrol acetate (NOMAC) is a widely used progestin-like drug that could be suggested as an alternative for patients taking CPA. We report a case of CPA-related meningioma for which relay from CPA to NOMAC led to further tumor growth and cessation of NOMAC-induced tumor shrinkage. We suggest NOMAC can have a similar effect than CPA on meningiomas. The use of NOMAC as replacement for CPA in the presence of a meningioma should be discouraged until further evidence becomes available on the role of NOMAC in such instances.

Isolation, synthesis, and cytotoxicity evaluation of two impurities in nomegestrol acetate

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth-generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6-methylene to 6-methyl-6,7-unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF-7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 μM). NOMAc and impurity A showed cytotoxicity to L02, MCF-7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested.

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.

Interbirth intervals in wild baboons: Environmental predictors and hormonal correlates

OBJECTIVES

Interbirth intervals (IBIs) are a key metric of female reproductive success; understanding how they are regulated by environmental, social, and demographic factors can provide insight into sources of variance in female fitness.

MATERIALS AND METHODS

Using 36 years of reproductive data on 490 IBIs for 160 wild female baboons, we identified sources of variance in the duration of IBIs and of their component phases: postpartum amenorrhea (PPA), sexual cycling, and pregnancy. We also examined how body fat and fecal hormone concentrations varied during female IBIs.

RESULTS

We found that IBIs tended to be shorter (reproduction was accelerated) when female traits and environmental variables promoted energy acquisition, but with different specific effects for different component phases of the IBI. We also found that females lost a substantial amount of body fat during PPA, indicating that PPA imposes accumulating energetic costs as it progresses. Prior to cycle resumption females began to regain body fat; body fat was stable across the cycling phase and increased throughout most of pregnancy. However, body fat scores per se were not associated with the duration of any of the component phases. Finally, we found that fecal glucocorticoid concentrations decreased as PPA progressed, suggesting a decline in energetic stress over this phase. Fecal progestogen and estrogen concentrations changed over time during sexual cycling; the direction of these changes depended on the phase of the sexual cycle (luteal versus early or late follicular phases).

DISCUSSION

Our study lends insight into the energetic constraints on female primate reproduction, revealing how female environments, changes in body fat, and steroid hormone concentrations relate to IBI duration and to reproductive readiness.

Biphasic modulation of cAMP levels by the contraceptive nomegestrol acetate. Impact on P-glycoprotein expression and activity in hepatic cells

ABC transporters are key players in drug excretion with alterations in their expression and activity by therapeutic agents potentially leading to drug-drug interactions. The interaction potential of nomegestrol acetate (NMGA), a synthetic progestogen increasingly used as oral contraceptive, had never been explored. In this work we evaluated (1) the effect of NMGA on ABC transporters in the human hepatic cell line HepG2 and (2) the underlying molecular mechanism. NMGA (5, 50 and 500 nM) increased P-glycoprotein (P-gp) expression at both protein and mRNA levels and reduced intracellular calcein accumulation, indicating an increase also in transporter activity. This up-regulation of P-gp was corroborated in Huh7 cells and was independent of the classical progesterone receptor. Instead, using a siRNA-mediated silencing approach, we demonstrated the involvement of membrane progesterone receptor α. Moreover, we found that the activation of this receptor by NMGA led to a falling-rising profile in intracellular cAMP levels and protein kinase A activity over time, ultimately leading to transcriptional P-gp up-regulation. Finally, we identified inhibitory G protein and phosphodiesterases as mediators of this novel biphasic modulation. These results demonstrate the ability of NMGA to selectively up-regulate hepatic P-gp expression and activity and constitute the first report of ABC transporter modulation by membrane progesterone receptor α. If a similar regulation took place in vivo, decreased bioavailability and therapeutic efficacy of NMGA-coadministered P-gp substrates could be expected. This holds special importance considering long-term administration of NMGA and broad substrate specificity of P-gp.

Body composition and psychological improvement in healthy premenopausal women assuming the oral contraceptive containing micronized estradiol (E2) and nomegestrol acetate (NOMAC)

This observational study was conducted in healthy premenopausal women, who presented themselves for contraceptive advice at the outpatient Family Planning Clinics of the Department of Obstetrics and Gynecology of the University of Cagliari, Hospital-University of Cagliari (Italy). After a screening period of three menstrual cycles, 48 women without contraindications to estroprogestin contraceptives (OCs) were included in the study. The primary purposes of the study were to evaluate whether a 12-month-treatment with the combined OC containing micronized estradiol (1.5 mg, E2) plus nomegestrol acetate (2.5 mg, NOMAC) (E2/NOMAC) interfere on anthropometric indices (AI), body composition (BC) and psychological status (PS). In subjects with dysmenorrhea (#36), its intensity was evaluated using the visuo analogic scale (VAS), both before and during the 12-month-treatment with E2/NOMAC. E2/NOMAC did not modify neither AI nor BC in the 40 subjects who concluded the study. The PS and the VAS of dysmenorrhea were significantly (p < 0.0001) improved from the first cycle of treatment and throughout the E2/NOMAC treatment in comparison with basal values. The study suggests that E2/NOMAC is devoid of negative effects on AI and BC, with additional benefits on PS and dysmenorrhea.

The effects of progesterones on blood lipids in hormone replacement therapy

The safety of progestogens as a class has drawn much attention after the publication of data from the Women’s Health Initiative (WHI) trial, particularly with respect to cardiovascular disease. Depending on the chemical structure, pharmacokinetics, receptor affinity and potency of action, progestogens have a divergent range of properties that may translate to very different clinical effects. The purpose of this review is to describe the role of varied progestogens in hormone replacement therapy (HRT), especially focusing on blood lipids, which are the most important parameters for assessing cardiovascular disease risk.

Ultra-performance liquid chromatography-tandem mass spectrometry assay for determination of plasma nomegestrol acetate and estradiol in healthy postmenopausal women

A highly sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry method is described for the simultaneous determination of nomegestrol acetate (NOMAC), a highly selective progestogen, and estradiol (E2), a natural estrogen in human plasma. NOMAC was obtained from plasma by solid-phase extraction, while E2 was first separated by liquid-liquid extraction with methyl tert-butyl ether followed by derivatization with dansyl chloride. Deuterated internal standards, NOMAC-d5 and E2-d4 were used for better control of extraction conditions and ionization efficiency. The assay recovery of the analytes was within 90-99%. The analytes were separated on UPLC BEH C₁₈ (50 × 2.1 mm, 1.7 μm) column using a mobile phase comprising of acetonitrile and 3.0 mm ammonium trifluoroacetate in water (80:20, v/v) with a resolution factor (R_s ) of 3.21. The calibration curves were linear from 0.01 to 10.0 ng/mL for NOMAC and from 1.00 to 1000 pg/mL for E2, respectively. The intra- and inter-batch precision was ≤5.8% and the accuracy of quality control samples ranged from 96.7 to 103.4% for both analytes. The practical applicability of the method is demonstrated by analyzing samples from 18 healthy postmenopausal women after oral administration of 2.5 mg nomegestrol acetate and 1.5 mg estradiol film-coated tablets under fasting.

Improvement of Low Sexual Desire Due to Antiandrogenic Combined Oral Contraceptives After Switching to an Oral Contraceptive Containing 17β-Estradiol

OBJECTIVES

To investigate the effects of a combined oral contraceptive (COC) containing 17β-estradiol (E2) 1.5 mg and nomegestrol acetate 2.5 mg (NOMAC/E2) on the sexual health of women affected by low sexual desire due to COCs containing ethinylestradiol.

MATERIALS AND METHODS

Eighty-three women (age range 19-32) participated in the study. Sex hormone-binding globulin (SHBG), total testosterone (TT), and free androgen index (FAI) were measured. The Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale (FSDS) questionnaires were used to assess sexual function and distress, respectively. Hormonal levels were measured and questionnaires were administered before the women switched COC NOMAC/E2 usage (baseline) and at the 3-month (first) and 6-month (second) follow-ups.

RESULTS

SHBG reduction (p < 0.001), TT (p < 0.05), and FAI increases (p < 0.001) were observed during the first and second follow-ups with respect to baseline values. Sexual desire increased from baseline to the first and second follow-ups (p < 0.001). At baseline, the total FSFI score was 22 ± 1.5 and the FSDS score was 16.6 ± 1.3, both indicating sexual dysfunction with sexual distress. At the first follow-up, the total FSFI score and the FSDS score increased toward sexual health values, being 28.3 ± 1.6 and 12.1 ± 1.5, respectively (p < 0.001). At the second follow-up, the FSFI score had risen to 30.6 ± 1.3 (p < 0.001) and the FSDS score had dropped to 8.3 ± 1.4 (p < 0.001).

CONCLUSIONS

COCs containing E2 are an innovation that could help women to not suffer from low sexual desire during hypoandrogenic COC usage.

Nomegestrol acetate/17-beta estradiol: a review of efficacy, safety, and patient acceptability

Nomegestrol acetate (NOMAC) 2.5 mg with 17-beta estradiol (E2) 1.5 mg is a new combined oral contraceptive (COC) formulation and is the first monophasic E2 pill to be marketed, having been licensed for use in Europe in 2011. It is available to be taken daily in a regimen of 24 active pills followed by four placebo pills. NOMAC is a highly selective 19-nor progestogen derivative with specific binding to progesterone receptors, anti-estrogenic activity and no androgenic, mineralocorticoid nor glucocorticoid effects. E2 is an estrogen that is identical to endogenous estrogen. While it has been in use for only a short period of time, current evidence suggests that NOMAC/E2 is just as effective, safe, and acceptable as existing COC preparations. Two large Phase III trials conducted in the Americas and across Europe, Australia, and Asia showed lower cumulative pregnancy rates in the NOMAC/E2 groups compared to the drospirenone (DRSP) 3 mg in combination with ethinyl estradiol (EE) 30 µg (DRSP/EE) groups but this difference was not statistically significant. NOMAC/E2 exhibits a good safety profile and has less effects on cardiovascular risk, hemostatic, metabolic, and endocrine factors in comparison to COCs containing EE in combination with levonorgestrel (LNG) or DRSP. NOMAC/E2 has also been found to cause less breast cell proliferation when compared to E2 alone and has some anti-proliferative effect on human breast cancer cells. NOMAC/E2 is considered acceptable as its compliance, continuation rates, and bleeding patterns were similar to COCs containing DRSP/EE and LNG 150 µg combined with EE 30 µg or LNG 100 µg combined with EE 20 µg (LNG/EE). However, discontinuation was found to be slightly higher in the NOMAC/E2 groups in the two large Phase III trials comparing NOMAC/E2 use with DRSP/EE. As the scientific literature has limited information on NOMAC/E2, further experience with NOMAC/E2 is required.

Epidemiology of hormonal contraceptives-related venous thromboembolism

For many years, it has been well documented that combined hormonal contraceptives increase the risk of venous thromboembolism (VTE). The third-generation pill use (desogestrel or gestodene (GSD)) is associated with an increased VTE risk as compared with second-generation (levonorgestrel) pill use. Other progestins such as drospirenone or cyproterone acetate combined with ethinyl-estradiol (EE) have been investigated. Most studies have reported a significant increased VTE risk among users of these combined oral contraceptives (COCs) when compared with users of second-generation pills. Non-oral combined hormonal contraception, such as the transdermal patch and the vaginal ring, is also available. Current data support that these routes of administration are more thrombogenic than second-generation pills. These results are consistent with the biological evidence of coagulation activation. Overall, the estrogenic potency of each hormonal contraceptive depending on both EE doses and progestin molecule explains the level of thrombotic risk. Some studies have shown a similar increased VTE risk among users of COCs containing norgestimate (NGM) as compared with users of second-generation pill. However, for this combination, biological data, based on quantitative assessment of sex hormone-binding globulin or haemostasis parameters, are not in agreement with these epidemiological results. Similarly, the VTE risk associated with low doses of EE and GSD is not biologically plausible. In conclusion, newer generation formulations of hormonal contraceptives as well as non-oral hormonal contraceptives seem to be more thrombogenic than second-generation hormonal contraceptives. Further studies are needed to conclude on the combinations containing NGM or low doses of EE associated with GSD.

Effects of estroprogestins containing natural estrogen on vaginal flora

Estroprogestins with "natural oestrogen" has represented a new option in terms of combined hormonal contraception. So, the aim of this study is to investigate how estroprogestins with natural estrogen may modify the vaginal niche. In literature, very few studies focused on the interaction between hormonal contraception and vaginal milieu. This is a prospective comparative study. We enrolled 60 women from January 2013 to September 2013, 30 of them were administered estradiol valerate dienogest (E2V+DNG - Klaira®) in a quadriphasic regimen, while the other 30 women were administered 17-β estradiol with nomestrol acetate (EV+NOMAC - Zoely®) in a monophasic regimen. After a baseline study of vaginal milieu at recruitment of patients (Gram stain with Nugent score, vaginal pH, vaginal wet mount for the quantification of leukocytes, Lactobacilli and/or presence of Candida), we performed the same follow-up after six months of estroprogestin therapy. Our results showed that the women treated with E2V+DNG had a trend of an improvement of vaginal health in terms of increase of lactobacillar flora and reduction of vaginal pH in place of women treated with EV+NOMAC that showed a reduction of cervical mucus. Finally, our data about the effects on vaginal flora exerted by two estroprogestin pills (EPs) containing a natural estrogen suggest slight, but interesting differences in terms of vaginal ecology. These differences could be related to the type of estrogen, type of progestin, regimen of administration and, after all, to the net balance between estrogenic and progestin component of the EPs.

The "newer" progestogens and postmenopausal hormone therapy (HRT)

After a worldwide breakdown of hormone therapy [HT] following the publications of the Women's Health Initiative trial and Million Women's Study in 2002-2003, there is now a trend to turn attention again to HT and to explore particular progestogens, which have been discredited with respect to their side effects. The progestogens to be considered should control undue proliferation of the endometrium and should not interfere negatively with the positive effects of estradiol, regarding carbohydrate and lipid metabolism as well as hemostasis. In the present review, three "newer progestogens" are scrutinized regarding their various actions, in combination with estradiol; the progestogens include dienogest, drospirenone and nomegestrol acetate. This article is part of a special issue entitled Menopause.

Classical and newly recognised non-contraceptive benefits of combined hormonal contraceptive use in women over 40

Although age is the most crucial predictor of a woman's reproductive capacity, it is assumed that there is still a risk of pregnancy in menopause transition, as occasional spontaneous ovulation is possible. Moreover, age alone is not sufficient to contraindicate the use of any contraceptive method, whether hormonal or not. The use of new CHC in women over 40 has not only been associated with an improved safety profile but has also been associated with other non-contraceptive benefits or the consolidation of already-known benefits. The studies with new CHC have demonstrated that efficacy and safety do not differ from the corresponding parameters observed in younger women. Additionally, the new CHC offers specific and especially useful benefits for women over 40 in the treatment of menstrual disorders. Finally, interest is currently focused on the potential of early diagnosis and the prevention of cardiovascular disease and depression, both of which may be alleviated by the CHC.

Are we overestimating the stroke risk related to contraceptive pills?

PURPOSE OF REVIEW

Hormonal contraceptives are used by million of women worldwide. Ischemic stroke is one of the major harmful effects of hormonal contraceptives, but remains a very uncommon disease before menopause. The increased risk of stroke under third and fourth-generation contraceptive pills and nonoral contraceptives has been recently highlighted. Given the benefits associated with combined hormonal contraceptives (COCs), it is important to properly evaluate their risks in order to provide a better benefit/risk balance to young women.

RECENT FINDINGS

Scarce studies addressing the rates of stroke in young women suggest that the fraction attributable to the contraceptive pill remains low. In contrast, there is abundant literature on the relative risks of stroke under COCs. The risk of arterial disease seems to be similar among users of second and third-generation pills, drospirenone-containing pills and nonoral hormonal contraceptives. Progestin-only contraceptives do not appear to be associated with an increased risk of stroke.

SUMMARY

New formulations of hormonal contraceptives are not safer than second-generation COCs. Even if the absolute numbers of strokes attributable to hormonal contraceptives is very low, stringent selection of patients should help to reduce the events still more, and progestin-only contraceptives/nonhormonal methods should be preferred in cases of associated risk factors.

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

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

Toward a new concept of "natural balance" in oral estroprogestin contraception

The Pill has undergone many changes since its first appearance some 50 years ago. Key developments included the reduction of ethinylestradiol doses and the synthesis of new progestins in order to increase safety, compliance and efficiency. Low-dose combined oral contraceptives (COCs) are currently the preferred option for millions of women. Due to this widespread use, it has been argued that the safety of COCs should be even better, raising the threshold for excellence. Yet in spite of major improvements, there is still an associated risk of venous thromboembolism (VTE). The next step in COCs' evolution should take total estrogenicity and hepatic estro-androgenic balance into account. The focus on the estrogen component--which has not changed in 50 years--has yielded a new class of natural estrogen pills. Following the introduction of a first quadriphasic pill, a monophasic estradiol pill based on the concept of "natural balance" was subsequently made available. These recent achievements could represent a step forward in the evolution of COCs and pave the way for better safety.

Nomegestrol acetate-17b-estradiol for oral contraception

Oral contraceptives remain a popular method of contraception over 50 years after their introduction. While safe and effective for many women, the failure rate of oral contraception is about 8%. Concerns about the risk of venous thromboembolism continue to drive the search for the safest oral contraceptive formulations. The oral contraceptive NOMAC-E2 contains nomegestrol acetate (NOMAC) 2.5 mg + 17b-estradiol (E2) 1.5 mg. The approved dosing regimen is 24 days of active hormone, followed by a 4-day hormone-free interval. NOMAC is a progestin derived from testosterone, which has high bioavailability, rapid absorption, and a long half-life. Estradiol, though it has a lower bioavailability, has been successfully combined with NOMAC in a monophasic oral contraceptive. Two recently published randomized controlled trials demonstrate that NOMAC-E2 is an effective contraceptive, with a Pearl Index less than one pregnancy per 100 woman-years. The bleeding pattern on NOMAC-E2 is characterized by fewer bleeding/spotting days, shorter withdrawal bleeds, and a higher incidence of amenorrhea than the comparator oral contraceptive containing drospirenone and ethinyl estradiol. The adverse event profile appears to be acceptable. Few severe adverse events were reported in the randomized controlled trials. The most common adverse events were irregular bleeding, acne, and weight gain. Preliminary studies suggest that NOMAC-E2 does not seem to have negative effects on hemostatic and metabolic parameters. While no one oral contraceptive formulation is likely to be the optimum choice for all women, NOMAC-E2 is a formulation with effectiveness comparable with that of other oral contraceptives, and a reassuring safety profile.

Efficacy and bleeding profile of a combined oral contraceptive containing oestradiol valerate/dienogest: a pooled analysis of three studies conducted in North America and Europe

OBJECTIVE

To summarise all clinical data on the contraceptive efficacy and bleeding profile associated with an oestradiol valerate (E2V) and dienogest (DNG) [E2V/DNG] combined oral contraceptive (COC) derived from Phase III trials.

METHODS

Pooled analysis of three large-scale multicentre trials conducted in healthy women who received oral E2V/DNG for 7 to 28 cycles (28-day cycles).

RESULTS

A total of 2266 women were included in this analysis. Overall, 19 pregnancies occurred over 13 cycles during 880,950 days of relevant exposure (Pearl Index [PI] of 0.79; upper limit of the two-sided 95% confidence interval [CI]: 1.23). Ten pregnancies attributed to method failure came about during 871,091 days of relevant exposure (adjusted PI of 0.42; upper limit of the two-sided 95% CI: 0.77). In women aged 18 to 35 years (n = 1687), the corresponding PI and adjusted PI were 1.01 (upper limit of the two-sided 95% CI: 1.59) and 0.51 (upper limit of the two-sided 95% CI: 0.97), respectively. In the first 13 cycles of treatment, 76 to 81% of women experienced scheduled withdrawal bleeding, and 13 to 23% experienced intracyclic bleeding.

CONCLUSIONS

E2V/DNG provides reliable contraceptive efficacy in women aged 18 to 50 years.

Progestogens used in postmenopausal hormone therapy: differences in their pharmacological properties, intracellular actions, and clinical effects

The safety of progestogens as a class has come under increased scrutiny after the publication of data from the Women's Health Initiative trial, particularly with respect to breast cancer and cardiovascular disease risk, despite the fact that only one progestogen, medroxyprogesterone acetate, was used in this study. Inconsistency in nomenclature has also caused confusion between synthetic progestogens, defined here by the term progestin, and natural progesterone. Although all progestogens by definition have progestational activity, they also have a divergent range of other properties that can translate to very different clinical effects. Endometrial protection is the primary reason for prescribing a progestogen concomitantly with postmenopausal estrogen therapy in women with a uterus, but several progestogens are known to have a range of other potentially beneficial effects, for example on the nervous and cardiovascular systems. Because women remain suspicious of the progestogen component of postmenopausal hormone therapy in the light of the Women's Health Initiative trial, practitioners should not ignore the potential benefits to their patients of some progestogens by considering them to be a single pharmacological class. There is a lack of understanding of the differences between progestins and progesterone and between individual progestins differing in their effects on the cardiovascular and nervous systems, the breast, and bone. This review elucidates the differences between the substantial number of individual progestogens employed in postmenopausal hormone therapy, including both progestins and progesterone. We conclude that these differences in chemical structure, metabolism, pharmacokinetics, affinity, potency, and efficacy via steroid receptors, intracellular action, and biological and clinical effects confirm the absence of a class effect of progestogens.

Hormonal contraceptives and venous thromboembolism: an epidemiological update

Since the early 1960s, it has been well documented that combined hormonal contraceptives increase the risk of cardiovascular disease. Newer generation of oral formulations, as well as non-oral contraceptives (transdermal and vaginal), have been recently studied for thrombotic risk. This review provides a summary of the association between hormonal contraceptives and venous thromboembolism with emphasis on new formulations of hormonal contraceptives as well as route of administration. A systematic search of Medline database was done for all relevant articles which included women having used third generation pills, and the development of new progestins. Eligible articles published in English and reporting the risk of venous thromboembolism (VTE) (pulmonary embolism or deep venous thrombosis) among users of hormonal contraceptives were reviewed. A quantitative assessment was made from included studies. Current use of drospirenone or cyproterone oral combined contraceptives increased the risk of VTE compared with second generation pills (pooled OR: 1.7; 95% confidence interval [95% CI]: 1.4-2.2 and OR: 1.8; 95% CI: 1.4-2.3, respectively). In the context of contraceptive use, non-oral route of ethinyl-estradiol administration seems to be more thrombogenic than oral route. In contrast, low doses of both oral progestin contraceptives and intrauterine levonorgestrel could be safe with respect to VTE risk. In conclusion, newer generation formulations of hormonal contraceptives, as well as the non-oral hormonal contraceptive, seem to be more thrombogenic than second generation hormonal contraceptives.

Characteristics and metabolic effects of estrogen and progestins contained in oral contraceptive pills

Estrogen and progestins have been used by millions of women as effective combined oral contraceptives. Oral contraceptives (OCs) modify surrogate markers such as lipoproteins, insulin response to glucose, and coagulation factors, that have been associated with cardiovascular and venous risk. Ethinyl-Estradiol (EE) exerts a stronger effect that natural estradiol (E2) on hepatic metabolism. New progestins with high specificity have been designed to avoid interaction with other receptors and prevent androgenic, estrogenic or glucocorticoid related side-effects. The risks and benefits of new progestins used in contraception depend upon their molecular structure, the type and dose of associated estrogen, and the delivery route. The lower impact of E2-based combinations on metabolic surrogate markers may result in an improved safety profile, but only clinical outcomes are relevant to assess the risk. Large surveillance studies are warranted to confirm this hypothesis.

Hormonal contraceptives and arterial disease: an epidemiological update

The cardiovascular safety of widely used combined hormonal contraceptives is still debated. Newer generations of oral formulations as well as non-oral contraceptives (transdermal and vaginal) have been recently evaluated in the context of cardiovascular disease. This review provides a summary of the association between combined oral contraceptives (COCs) and arterial diseases, with an emphasis on new formulations of hormonal contraceptives, as well as routes of administration. A systematic search of the Medline database was performed to find all relevant articles which included women who had widely use third generation pills, and the development of new progestins. Eligible articles published in English and reporting risk of arterial events (myocardial infarction [MI] and stroke) among users of hormonal contraceptives were reviewed. A quantitative assessment was made from included studies. Overall, current use of oral combined contraceptives increased the risk of MI and ischemic stroke (pooled OR: 1.7; 95% confidence interval [95% CI]: 1.2-2.3 and OR: 1.8; 95% CI: 1.2-2.8, respectively), but this was not associated with the risk of hemorrhagic stroke (OR: 1.1; 95% CI: 0.7-1.9). The increase in ischemic arterial disease was higher among first generation pill users compared with second or third generation pill users. In contrast, risk of ischemic arterial disease among current users of second or third generation pill was similar (p = 0.23 for MI risk and 0.99 for ischemic stroke). In conclusion, newer generation formulations of COCs, as well as the non-oral hormonal contraceptive, do not seem to be safer than second generation hormonal contraceptives.

Progesterone and related compounds in hepatocellular carcinoma: basic and clinical aspects

Primary liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. Hepatocellular carcinoma (HCC) accounts for 85% to 90% of primary liver cancers. Major risk factors for HCC include infection with HBV or HCV, alcoholic liver disease, and most probably nonalcoholic fatty liver disease. In general, men are two to four times more often associated with HCC than women. It can be suggested that sex hormones including progesterone may play some roles in HCC. Rather, very limited information discusses its potential involvement in HCC. This paper thus collects some recent studies of the potential involvement of progesterone and related compounds in HCC from basic and clinical aspects. In addition, two synthetic progestins, megestrol acetate (MA) and medroxyprogesterone acetate (MPA), will be discussed thoroughly. It is noted that progesterone can also serve as the precursor for androgens and estrogens produced by the gonadal and adrenal cortical tissues, while men have a higher incidence of HCC than women might be due to the stimulatory effects of androgen and the protective effects of estrogen. Eventually, this paper suggests a new insight on the associations of progesterone and related compounds with HCC development and treatment.

A New Contraceptive Pill Containing 17β-Estradiol and Nomegestrol Acetate

Most combined oral contraceptive pills contain ethinyl estradiol (EE) with progestins. In order to minimize the pill's cardiovascular risks, the concept of using 17β-estradiol (E2), the endogenous estradiol, arose in the 1970s. Many attempts to develop a pill containing 17β-E2 have failed as cycle control was low. The first pill containing 17β-E2 was launched in 2011. This monophasic pill contains 24 pills with 1.5 mg 17β-E2 and 2.5 mg nomegestrol acetate, and four placebo pills. Studies conducted in Europe and the USA demonstrate that its Pearl index is 0.38 and 1.13, respectively. It has less influence on hemostasis, fibrinolysis markers, lipids and carbohydrate metabolism than the combined oral contraceptive levonorgestrel/EE (150 g/30 g and 100 μg/20 μg). Withdrawal bleedings are shorter and lighter as compared with women using drospirenone/EE (3 mg/30 μg). The number of women without withdrawal bleeding is approximately 30% after 12 months. Even though its contraindications are identical to other combined oral contraceptives, this nomegestrol acetate/E2 pill should be considered to be of interest for many women.

Defective DNA repair systems and the development of breast and prostate cancer (review)

Genetic defects in DNA repair and DNA damage response genes often lead to an increase in cancer incidence. The role of defects is also associated with the modulation of hormone signaling pathways. A number of studies have suggested a role for estrogen in the regulation of DNA repair activity. Furthermore, mutations or epigenetic silencing in DNA repair genes have been associated with the sensitivity of cancers to hormonal therapy. The molecular basis for the progression of cancers from hormone-dependent to hormone-independent remains a critical issue in the management of these types of cancer. In the present review, we aimed to summarize the function of DNA repair molecules from the viewpoint of carcinogenesis and hormone-related cell modulation, providing a comprehensive view of the molecular mechanisms by which hormones may exert their effects on the regulation of tumor progression.

Nomegestrol acetate sequentially or continuously combined to estradiol did not negatively affect membrane-receptor associated progestogenic effects in human breast cancer cells

OBJECTIVES

Recently the first monophasic contraceptive pill containing estradiol has been developed which is thought to be a milestone in contraception. Nomegestrol acetate (NOM) is the progestogenic component. Progesterone receptor membrane component 1 (PGRMC1) is highly expressed in the tissue of breast cancer patients, and can predict a progestogen dependent risk of breast cancer.

METHODS

MCF-7 cells were transfected with PGRMC1 expression plasmid, and were stimulated with estradiol (E2, 10(-12) and 10(-10) M). NOM, progesterone (P), medroxyprogesterone acetate (MPA) and norethisterone (NET) (each 10(-7) M) were added sequentially or continuously.

RESULTS

E2 at 10(-10) M elicited a significant increase of cell proliferation from 150 to 200%. No effect was seen at 10(-12) M. Addition of the progestogens to E2 at 10(-10) M had no significant effect. However, at an E2 10(-12) M, NET significantly stimulated cell proliferation more pronounced in the continuous combined model. No effect was seen for NOM, P and MPA. The E2/NET combined effect could be abrogated by the addition of an estrogen receptor (ER) antagonist.

CONCLUSION

Since NOM did not increase proliferation it may be concluded that it will be neutral in terms of breast cancer risk when combined with E2 at least in women overexpressing PGRMC1.

Preclinical pharmacological profile of nomegestrol acetate, a synthetic 19-nor-progesterone derivative

BACKGROUND

Nomegestrol acetate (NOMAC), a synthetic progestogen derived from 19-nor-progesterone, recently completed clinical trials for use with 17beta-estradiol in a new monophasic combined oral contraceptive. In this review, published as well as previously unpublished preclinical studies that detail the effects of NOMAC on estrogenic, progestogenic, and androgenic systems, as well as mineralocorticoid, glucocorticoid, bone, and metabolic indices are described.

METHODS

In vitro assays to determine NOMAC structure-activity relationships used tissue derived from rat uteri. Transactivation profiles were performed using Chinese hamster ovary (CHO) cells transfected with cDNAs encoding human steroid receptors. Estrogenic and anti-estrogenic activities were monitored in vivo in rats as well as in vitro in human breast cancer cells. Standard in vivo techniques were used in rats to determine progestational activity; antigonadotropic, androgenic, mineralocorticoid, and glucocorticoid activities; as well as effects on bone and other metabolic indices. Ovulation inhibition was monitored in rats and primates. NOMAC's effects on cardiovascular systems were determined in dogs and primates.

RESULTS

NOMAC was without significant agonistic or antagonistic activity for estrogen receptor alpha or beta in vitro, and inhibited ovulation in rats and monkeys (2.5 mg/kg and 1 mg/kg, respectively). NOMAC lacked androgenic, antimineralocorticoid, glucocorticoid, and metabolic activity and exhibited moderate anti-androgenic activity in rats. NOMAC did not affect bone mineral density (BMD) in rats or hemodynamic and electrophysiologic parameters in dogs and primates.

CONCLUSIONS

NOMAC is a selective progestogen structurally similar to progesterone that has modest anti-androgenic activity and does not affect lipid or carbohydrate metabolism, BMD, or many cardiovascular parameters in selected animal models.

Pharmacokinetic profile of nomegestrol acetate and 17β-estradiol after multiple and single dosing in healthy women

BACKGROUND

The pharmacokinetics of the monophasic oral contraceptive nomegestrol acetate (NOMAC) plus 17β-estradiol (E(2)) were investigated after a single dose and multiple dosing.

STUDY DESIGN

NOMAC/E2 (2.5 mg/1.5 mg) was administered daily to healthy women (18-50 years, n=23) for 24 days; blood samples for pharmacokinetic analysis were obtained on Day 24 and again, after a 10-day pill-free interval, on Day 35 after a single dose.

RESULTS

NOMAC reached steady state after 5 days with mean ±standard deviation (SD) trough NOMAC concentration (C(av)) of 4.4±1.4 ng/mL. On Day 24, mean±SD peak NOMAC concentration (Cmax, 12.3±3.5 ng/mL) was reached in mean 1.5 h (t(max)); the mean±SD elimination half-life (t(½)) was 45.9±15.3 h. After a single dose, NOMAC mean±SD C(max) was 7.2±2.0 ng/mL and mean±SD t(½) was 41.9±16.2 h. On Day 24, E2 mean±SD C(av) was 50.3±25.7 pg/mL; mean±SD Cmax was 86.0±51.3 pg/mL. After a single dose, mean±SD E2 Cmax was 253±179 pg/mL.

CONCLUSIONS

These data demonstrate that NOMAC/E2 has a pharmacokinetic profile consistent with once-daily dosing.

Multiple nuclear receptor signaling pathways mediate the actions of synthetic progestins in target cells

Synthetic progestins are used clinically to treat a variety of women's health issues. Although progestins are designed to signal through the progesterone receptor (PR) to elicit specific pharmacological effects, they can also variably bind to and influence the activity of other nuclear receptors within target tissues, particularly the androgen and glucocorticoid receptors and, in some cases, they regulate mineralocorticoid and estrogen receptors. This article reviews current knowledge on progestin cross-talk to nuclear receptors other than PR, their resultant effect on receptor function in different in vitro models and the potential consequences of this activity for breast, ovarian and endometrial cancer. The impact of cell and tissue context, assay type, steroid metabolism and hormonal milieu in determining progestin-mediated activity are also presented. Collectively this review highlights the complexity of progestin action and the need for consideration of multiple mechanisms that act in concert to influence their ultimate biological activity.

Progesterone and levonorgestrel regulate expression of 17βHSD-enzymes in progesterone receptor positive breast cancer cell line T47D

The use of combined hormone replacement therapy (HRT) with oestrogens and progestins in postmenopausal women has been associated with an increased risk for developing breast cancer. The reasons are not fully understood, but influence of HRT on endogenous conversion of female sex hormones may be involved. The expression of 17β hydroxysteroid dehydrogenases (17βHSD), which are enzymes catalysing the conversion between more or less potent oestrogens, may partly be regulated by progestins. The breast cancer cell lines T47D, MCF7 and ZR75-1 were treated with progesterone, medroxyprogesterone acetate (MPA) or levonorgestrel for 48 and 72 h at 10(-7) and 10(-9)M to investigate influence on 17βHSD1, 17βHSD2 and 17βHSD5 mRNA expression measured by real time PCR. The expression of 17βHSD1 increased in progesterone and levonorgestrel treated T47D cells (48 h 10(-7)M P=0.002; P<0.001) and 17βHSD5 increased after progesterone treatment (48 h 10(-7)M P=0.003), whereas the expression of 17βHSD2 decreased after the (48 h 10(-7)M P=0.003; P<0.001). Similar, but less prominent effects were seen in MCF7 and ZR75-1. The progestin effects on 17βHSD-expression were lost when T47D cells were co-treated with progestins and the progesterone receptor (PgR) inhibitor mifprestone. We show that both reductive (17βHSD1 and 17βHSD5) and oxidative (17βHSD2) members of the 17βHSD-family are under control of progesterone and progestins in breast cancer cell lines. This is most clear in T47D cells which have high PgR expression. 17βHSD-enzymes are important players in the regulation of sex steroids locally in breast tumours and tumoural expression of various 17βHSD-enzymes have prognostic and treatment predictive relevance. We propose a mechanism for increased breast cancer risk after HRT in which hormone replacement affects the expression of 17βHSD-enzymes, favouring the expression of reductive enzymes, which in turn could increase levels of bioactive and mitogenic estrogens in local tissue, e.g. breast tissue.