Prediction of the change in bone mineral density induced by gonadotropin-releasing hormone agonist treatment for endometriosis

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease on the background of progesterone resistance. Increased estrogen production, low estrogen metabolization, and altered estrogen receptors (ERs) expression contribute to the hyperestrogenic milieu within endometriotic lesions. Since estrogens play a crucial role in the pathogenesis of the disease, inhibition of estrogen production is one of the main targets of available and emerging drugs.

AREAS COVERED

Firstly, we described the molecular alterations responsible for estrogen dependence. Secondly, we reviewed available and emerging treatments that interfere, through central (gonadotropin-releasing hormone analogs (GnRH-a), GnRH antagonists) or local mechanisms (aromatase inhibitors (AIs), inhibitors of steroid sulfatase (STS) and hydroxysteroid dehydrogenase type 1 (17β-HSD1)), with estrogen dependence. Finally, we focused on emerging treatments targeting ERs (selective estrogen receptor modulators (SERMs), estrogen receptors agonists, and antagonists).

EXPERT OPINION

Available treatments interfering with estrogen pathways exert a contraceptive effect, have hypoestrogenic side effects, and cannot prevent or definitively treat the disease. Preclinical and animal studies are focusing on emerging drugs targeting ERs in order to overcome limitations of available treatments. These treatments may represent a promising option, as they may produce a more specific inhibition of disease activity within endometriotic implants, avoiding prolonged hypoestrogenic status and limiting systemic side effects.

Evidence-Based Management of Uterine Fibroids With Botanical Drugs-A Review

Uterine fibroids (UFs) are a common benign gynecological tumor that affect the majority of women over their lifetime. Several pharmacological agents are available to reduce the size of fibroids and ameliorate the symptoms of UF. However, these drugs are expensive and are usually associated with profound side effects. Thus, botanical drugs are gaining attention in this era due to their cost effectiveness with a comparable and more potent therapeutic efficacy while demonstrating lesser adverse effects. The objective of this review is to summarize the available information on the mechanism of various botanical drugs and polyherbal formulations with anti-uterine fibroid activity. A systematic search was performed on botanical drugs with anti-uterine fibroid activity using several search engines, which include PubMed, Google Scholar, and Science Direct. Based on the literatures identified, a total of five botanical drugs and three polyherbal formulations were included and discussed in this review, which yields useful information regarding the mechanism of different botanical drugs and polyherbal formulations in exerting anti-uterine fibroid activity for its potential use as an alternative treatment choice for uterine fibroids.

The effect of pharmacological cessation and restoration of menstrual cycle on bone metabolism in premenopausal women with endometriosis

INTRODUCTION

GnRH-analogs induce bone loss. We aimed to investigate the effects of goserelin-induced menstrual cessation (MC) and subsequent menstrual restoration (MR) on bone metabolism (BM).

METHODS

In this prospective cohort study, premenopausal women (PMW) with histologically verified endometriosis (n = 21) received goserelin monthly for 6 months (6 m) resulting in MC and were followed up for another 6 m after MR (12 m). Age- and BMI-matched healthy PMW (n = 20) served as controls for bone mineral density (BMD) measurements. The primary endpoint was changes in lumbar spine (LS)-BMD at 6 m and 12 m; Secondary endpoints were changes in femoral neck (FN)-BMD, bone turnover markers (P1NP and CΤx), sclerostin, and expression of bone-related circulating microRNAs (miRNAs) at 6 m and 12 m.

RESULTS

Goserelin-induced MC reduced LS- and FN-BMD at 6 m (both p < 0.001). From 6 m to 12 m, LS-BMD increased (p < 0.001) but remained below baseline values (p = 0.012), whereas FN-BMD remained stable (p = 1.000). CTx and P1NP levels increased at 6 m (both p < 0.001) and decreased at 12 m (p < 0.001 and p = 0.013, respectively), while CTx (p = 1.000) alone and not P1NP (p = 0.020) returned to baseline. Sclerostin levels did not change. Relative expression of miRNAs targeting RUNX 2 and beta-catenin was significantly downregulated at 6 m compared to baseline (p < 0.001), while the expression of miRNAs targeting osteoblast and osteoclast function at both directions demonstrated a robust increase (up to 400fold) at 12 m (p < 0.001).

CONCLUSIONS

Six months of goserelin-induced MC lead to significant bone loss associated with increased bone turnover and changes in the expression of bone-related miRNAs, changes that are only partially reversed at 6 m after MR.

The Relationship Between Bone and Reproductive Hormones Beyond Estrogens and Androgens

Reproductive hormones play a crucial role in the growth and maintenance of the mammalian skeleton. Indeed, the biological significance for this hormonal regulation of skeletal homeostasis is best illustrated by common clinical reproductive disorders, such as primary ovarian insufficiency, hypothalamic amenorrhea, congenital hypogonadotropic hypogonadism, and early menopause, which contribute to the clinical burden of low bone mineral density and increased risk for fragility fracture. Emerging evidence relating to traditional reproductive hormones and the recent discovery of newer reproductive neuropeptides and hormones has deepened our understanding of the interaction between bone and the reproductive system. In this review, we provide a contemporary summary of the literature examining the relationship between bone biology and reproductive signals that extend beyond estrogens and androgens, and include kisspeptin, gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, prolactin, progesterone, inhibin, activin, and relaxin. A comprehensive and up-to-date review of the recent basic and clinical research advances is essential given the prevalence of clinical reproductive disorders, the emerging roles of upstream reproductive hormones in bone physiology, as well as the urgent need to develop novel safe and effective therapies for bone fragility in a rapidly aging population.

The recurrence rate of ovarian endometrioma in women aged 40-49 years and impact of hormonal treatment after conservative surgery

The aim of this study was to evaluate the rate of and risk factors for recurrence ovarian endometrioma after conservative surgery in patients aged 40–49 years. This retrospective, single-center study included 408 women between January 2008 and November 2018. All patients underwent ovarian cyst enucleation, were pathologically diagnosed with ovarian endometrioma and were followed up for ≥ 6 months. Recurrence was defined as a cystic mass with diameter ≥ 2 cm detected by sonography. Recurrence rate after conservative surgery and risk factor of recurrence were analyzed. The median follow-up duration after surgery was 32.0 ± 25.9 months (range 6–125 months). Ovarian endometrioma recurred in 34 (8.3%) of included women and median time to recurrence was 22.4 ± 18.2 months. The cumulative recurrences rate at 12, 24, 36, and 60 months were 3.7%, 6.7%, 11.1%, and 16.7%, respectively. Recurrence was correlated with multilocular cysts (p = 0.038), previous surgical history of ovarian endometrioma (p = 0.006) and salpingectomy (p = 0.043), but not use or duration of post-operative medication. In multivariate analysis, large cyst size (> 5.5 cm) was only risk factor for recurrence in this age group. Post-operative medication did not reduce disease recurrence rate, and thus may be administered for endometriosis-associated pain rather than to prevent recurrence in patients aged 40–49 years.

Short- and long-term impact of gonadotropin-releasing hormone analogue treatment on bone loss and fracture

Gonadotropin-releasing hormone analogues (GnRH-a) are commonly utilized in moderate to severe endometriosis to induce atrophy of endometriotic lesions. Unfortunately, cessation of therapy can lead to recurrence of symptoms. Therefore, long term therapy is sometimes necessary. GnRH analogues cause an immediate decrease in bone mineral density which usually recovers after cessation of its use. However, this recovery in bone mineral density may not always occur after long term use. In order to prevent the deleterious effects on bone, add-back therapy is used frequently. This review will explore the impact of GnRH analogues on both bone loss and fracture risk as well as describe different add-back regimens.

Comparison of long-term use of combined oral contraceptive after gonadotropin-releasing hormone agonist plus add-back therapy versus dienogest to prevent recurrence of ovarian endometrioma after surgery

OBJECTIVE

The aim of this study was to compare long-term use of combined oral contraceptive (COC) after gonadotropin-releasing hormone (GnRH) agonist plus add-back therapy with dienogest (DNG) treatment as medical treatments after surgery for ovarian endometrioma.

METHODS

This prospective cohort study analyzed 52 reproductive-aged women who underwent surgery for ovarian endometrioma and received postoperative medical treatment with either COC after GnRH agonist (n = 20) or DNG (n = 32) for 24 months. Changes in quality-of-life (QOL) and bone mineral density (BMD) were compared according to treatment. In addition, recurrence of pain and lesions were compared.

RESULTS

Baseline characteristics did not differ in demographic profiles and factors associated with endometriosis or QOL. During 24 months of treatment, no differences in any component of QOL were found between the two groups. BMD at the lumbar spine significantly decreased after the first 6 months of treatment in both COC after GnRH agonist (-3.5%) and DNG (-2.3%) groups, but the groups did not differ statistically. After 6 months, further decrease in BMD was not observed until 24 months in both groups. In addition, no cases of pain or endometrioma recurrence were found.

CONCLUSION

Our results suggest that long-term use of COC after GnRH agonist plus add-back therapy is comparable to dienogest as a long-term postoperative medical treatment for endometriosis.

Gonadotropin-releasing hormone agonist with add-back treatment is as effective and tolerable as dienogest in preventing pain recurrence after laparoscopic surgery for endometriosis

PURPOSE

This study was performed to compare the efficacy and tolerability of GnRH agonist with add-back therapy versus dienogest treatment for preventing pelvic pain recurrence after laparoscopic surgery for endometriosis.

METHODS

Sixty-four reproductive-aged women who underwent laparoscopic surgery for endometriosis received post-operative medical treatment with either GnRH agonist plus 17β-estradiol and norethisterone acetate (n = 28) or dienogest (n = 36) for 6 months. The pre- to post-treatment changes in pain were assessed using a visual analogue scale, and changes in quality-of-life and menopausal symptoms were measured by questionnaire.

RESULTS

Visual analogue scale pain score decreased significantly for both treatments with no significant differences between groups. Neither physical, psychological, social, and environmental components of quality-of-life nor menopausal rating scale score were significantly different between the two groups. Bone mineral density at the lumbar spine declined significantly in both treatment groups (-2.5 % for GnRH agonist plus add-back and -2.3 % for dienogest), with no significant difference between the two groups.

CONCLUSION

GnRH agonist and add-back therapy using 17β-estradiol and norethisterone acetate are as effective and tolerable as dienogest for the prevention of pelvic pain recurrence after laparoscopic surgery for endometriosis.

Hormonal Add-Back Therapy for Females Treated With Gonadotropin-Releasing Hormone Agonist for Endometriosis: A Randomized Controlled Trial

OBJECTIVE

To assess whether add-back therapy with norethindrone acetate or norethindrone acetate plus conjugated equine estrogens is superior to maintain bone health in adolescents and young women using gonadotropin-releasing hormone agonists for endometriosis. Gonadotropin-releasing hormone agonists are associated with deleterious effects on bone. Hormonal add-back may mitigate these effects.

METHODS

Adolescents and young women (n=51) received a random, double-blind assignment to add-back with norethindrone acetate (5 mg/day) plus conjugated equine estrogens (0.625 mg/day) or norethindrone acetate plus placebo for 12 months. Body composition, bone mineral content, and bone mineral density (BMD) were obtained by dual-energy X-ray absorptiometry every 6 months. Quality-of-life measures were collected every 3 months. Intention-to-treat comparison of outcomes was conducted by repeated-measures analysis of variance.

RESULTS

Thirty-four adolescents and young women completed the trial; dropouts did not differ from those who completed the trial. Bone mineral density was normal at baseline. At 12 months, total body bone mineral content and BMD had increased in the norethindrone acetate plus conjugated equine estrogens group (bone mineral content +37 g, P<.001 and BMD +0.012 g/cm, P=.05), but not in those receiving norethindrone acetate plus placebo (bone mineral content P=.19 and BMD P=.95). Lean mass increased only in those receiving conjugated equine estrogens (+1.4 kg, P=.001). Improvements in physical functioning domains of quality-of-life assessments were greater with norethindrone acetate plus conjugated equine estrogens (P=.005). No differences were seen at the hip or lumbar spine by dual-energy X-ray absorptiometry. No significant adverse events occurred.

CONCLUSION

Hormonal add-back successfully preserved bone health and improved quality of life for adolescents and young women with endometriosis during 12 months of gonadotropin-releasing hormone agonist therapy. Combination norethindrone acetate plus conjugated equine estrogens add-back appears to be more effective for increasing total body bone mineral content, areal BMD, and lean mass than norethindrone acetate monotherapy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; www.clinicaltrials.gov, NCT00474851.

LEVEL OF EVIDENCE

I.

The use of gonadotropin releasing hormone analogues in adolescent and young patients with endometriosis

PURPOSE OF REVIEW

Endometriosis is increasingly being recognized and diagnosed in adolescents. As a result of this earlier diagnosis, treatment with agents like gonadotropin releasing hormone agonist (GnRHa) begins earlier and may last longer. Long-term effects of GnRHa treatment for endometriosis are of concern when treating adolescents.

RECENT FINDINGS

GnRHas are used for adolescents with surgically confirmed endometriosis. GnRHa treatment is effective for pain reduction, but is associated with menopausal symptoms and decreases in bone density. Different regimens of hormonal add-back therapy have been studied in adults to attempt to prevent these side-effects.

SUMMARY

GnRHa therapy is a highly effective, nonsurgical treatment option for many adolescents with endometriosis, but is accompanied by side-effects of bone loss and menopausal symptoms. Side-effects may be decreased by introducing appropriate add-back therapy. Monitoring of bone density by DXA is recommended for prolonged use of GnRHa in adolescents.

Integrated pharmacometrics and systems pharmacology model-based analyses to guide GnRH receptor modulator development for management of endometriosis

Endometriosis is a gynecological condition resulting from proliferation of endometrial-like tissue outside the endometrial cavity. Estrogen suppression therapies, mediated through gonadotropin-releasing hormone (GnRH) modulation, decrease endometriotic implants and diminish associated pain albeit at the expense of bone mineral density (BMD) loss. Our goal was to provide model-based guidance for GnRH-modulating clinical programs intended for endometriosis management. This included developing an estrogen suppression target expected to provide symptomatic relief with minimal BMD loss and to evaluate end points and study durations supportive of efficient development decisions. An existing multiscale model of calcium and bone was adapted to include systematic estrogen pharmacologic effects to describe estrogen concentration-related effects on BMD. A logistic regression fit to patient-level data from three clinical GnRH agonist (nafarelin) studies described the relationship of estrogen with endometrial-related pain. Targeting estradiol between 20 and 40 pg/ml was predicted to provide efficacious endometrial pain response while minimizing BMD effects.

Bone density in adolescents treated with a GnRH agonist and add-back therapy for endometriosis

STUDY OBJECTIVE

To evaluate the bone density of adolescents with endometriosis treated with a GnRH-agonist and "add-back" therapy with norethindrone acetate.

DESIGN

Retrospective chart review.

SETTING

Pediatric gynecology clinic at a tertiary care center.

PARTICIPANTS

36 adolescents, ages 13 to 21 years, with endometriosis.

MAIN OUTCOME MEASURES

Bone mineral density (BMD, g/cm(2)) by dual energy x-ray absorptiometry (DXA); BMD Z-scores of hip and spine.

RESULTS

The mean BMD Z-score at the total hip was -0.24 +/- 1.0, with a range of -2.4 to 1.7. At this site, 6 subjects had a BMD Z-score between -1.0 and -2.0 SD, while 2 had a Z-score < or = -2.0 SD. The mean BMD Z-score at the lumbar spine was 0.55 +/- 1.1, with a range of -2.8 to 1.4. At the spine, 11 subjects had a BMD Z-score between -1.0 and -2.0 SD, while 3 had a Z-score < or = -2.0 SD. There was no correlation noted between duration of therapy with the GnRH-agonist plus add-back and BMD at the hip or spine.

CONCLUSION

BMD at the hip was normal in most adolescents with endometriosis who were receiving a GnRH-agonist plus add-back therapy with norethindrone acetate. Almost one third of subjects exhibited skeletal deficits at the spine. These data suggest that BMD should be carefully monitored in adolescents receiving treatment with GnRH agonists.

Toward gene therapy of endometriosis: adenovirus-mediated delivery of dominant negative estrogen receptor genes inhibits cell proliferation, reduces cytokine production, and induces apoptosis of endometriotic cells

OBJECTIVE

To use dominant negative mutants of estrogen receptor genes delivered to endometriosis cells via an adenovirus vector (Ad-DN-ER) to abrogate estrogen action on these cells.

DESIGN

Experimental in vitro study.

SETTING

University research laboratory.

PATIENT(S)

Patients with ovarian endometriomas provided endometriotic cells, and patients with uterine prolapse or subserous leiomyoma provided control endometrial cells.

INTERVENTION(S)

Transfection of endometriotic cells by dominant negative estrogen receptor genes via adenovirus vector (Ad-DN-ER).

MAIN OUTCOME MEASURE(S)

The main outcome measures were cellular proliferation, cytokine production, and induction of apoptosis in endometriotic cells.

RESULT(S)

Coxsackievirus-adenovirus receptor mRNA expression and adenovirus transduction efficiency were significantly higher in endometriotic than normal endometrial cells. Ad-DN-ER-treated endometriotic cells, as compared with control virus-treated cells, showed cell rounding and detachment (cell death), a 72% reduction in the number of viable cells 5 days after transduction, significantly less production of monocyte chemotactic protein-1 (7.8 +/- 0.5 vs. 152.8 +/- 1.9 pg/mL, respectively), vascular endothelial growth factor (356.2 +/- 11.6 vs. 997.3 +/- 16.5 pg/mL, respectively), and interleukin-6 (268.7 +/- 2.6 vs. 414.5 +/- 3.6 pg/mL, respectively), and a significantly higher percentage of apoptotic cells (51.2 +/- 7.8 vs. 23.8 +/- 1.7, respectively).

CONCLUSION(S)

An adenovirus can effectively transfect endometriotic cells in vitro. The DN-ER delivered to endometriotic cells via an adenovirus decreases cell proliferation, induces apoptosis, and decreases cytokine production. Adenovirus-mediated gene therapy may represent a potential therapeutic option for endometriosis in the future.

GnRH analogs: options for endometriosis-associated pain treatment

While none of the currently available treatment options for endometriosis pain resolved the underlying disease process, there are growing numbers of medical alternatives available. Medical options include the GnRH agonists and antagonists. Review of these treatments in the management of endometriosis pain and the insight often to the etiology of endometriosis are presented for discussion.