Medroxyprogesterone acetate supplementation diminishes the hypoestrogenic side effects of gonadotropin-releasing hormone agonist without changing its efficacy in endometriosis

A systematic literature review on patient-reported outcome domains and measures in nonsurgical efficacy trials related to chronic pain associated with endometriosis: an urgent call to action

ABSTRACT

Endometriosis, a common cause for chronic pelvic pain, significantly affects quality of life, fertility, and overall productivity of those affected. Therapeutic options remain limited, and collating evidence on treatment efficacy is complicated. One reason could be the heterogeneity of assessed outcomes in nonsurgical clinical trials, impeding meaningful result comparisons. This systematic literature review examines outcome domains and patient-reported outcome measures (PROMs) used in clinical trials. Through comprehensive search of Embase, MEDLINE, and CENTRAL up until July 2022, we screened 1286 records, of which 191 were included in our analyses. Methodological quality (GRADE criteria), information about publication, patient population, and intervention were assessed, and domains as well as PROMs were extracted and analyzed. In accordance with IMMPACT domain framework, the domain pain was assessed in almost all studies (98.4%), followed by adverse events (73.8%). By contrast, assessment of physical functioning (29.8%), improvement and satisfaction (14.1%), and emotional functioning (6.8%) occurred less frequently. Studies of a better methodological quality tended to use more different domains. Nevertheless, combinations of more than 2 domains were rare, failing to comprehensively capture the bio-psycho-social aspects of endometriosis-associated pain. The PROMs used showed an even broader heterogeneity across all studies. Our findings underscore the large heterogeneity of assessed domains and PROMs in clinical pain-related endometriosis trials. This highlights the urgent need for a standardized approach to both, assessed domains and high-quality PROMs ideally realized through development and implementation of a core outcome set, encompassing the most pivotal domains and PROMs for both, stakeholders and patients.

Gonadotropin-releasing hormone analogues for endometriosis

BACKGROUND

Endometriosis is a common gynaecological condition affecting 6 to 11% of reproductive-age women and may cause dyspareunia, dysmenorrhoea, and infertility. One treatment strategy is medical therapy with gonadotrophin-releasing hormone analogues (GnRHas) to reduce pain due to endometriosis. One of the adverse effects of GnRHas is a decreased bone mineral density. In addition to assessing the effect on pain, quality of life, most troublesome symptom and patients' satisfaction, the current review also evaluated the effect on bone mineral density and risk of adverse effects in women with endometriosis who use GnRHas versus other treatment options.

OBJECTIVES

To assess the effectiveness and safety of GnRH analogues (GnRHas) in the treatment of painful symptoms associated with endometriosis and to determine the effects of GnRHas on bone mineral density of women with endometriosis.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO and the trial registries in May 2022 together with reference checking and contact with study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) which compared GnRHas with other hormonal treatment options, including analgesics, danazol, intra-uterine progestogens, oral or injectable progestogens, gestrinone and also GnRHas compared with no treatment or placebo. Trials comparing GnRHas versus GnRHas in conjunction with add-back therapy (hormonal or non-hormonal) or calcium-regulation agents were also included in this review.  DATA COLLECTION AND ANALYSIS: We used standard methodology as recommended by Cochrane. Primary outcomes are relief of overall pain and the objective measurement of bone mineral density. Secondary outcomes include adverse effects, quality of life, improvement in the most troublesome symptoms and patient satisfaction.  Due to high risk of bias associated with some of the studies, primary analyses of all review outcomes were restricted to studies at low risk of selection bias. Sensitivity analysis including all studies was then performed.

MAIN RESULTS

Seventy-two studies involving 7355 patients were included. The evidence was very low to low quality: the main limitations of all studies were serious risk of bias due to poor reporting of study methods, and serious imprecision.  Trials comparing GnRHas versus no treatment  We did not identify any studies. Trials comparing GnRHas versus placebo There may be a decrease in overall pain, reported as pelvic pain scores (RR 2.14; 95% CI 1.41 to 3.24, 1 RCT, n = 87, low-certainty evidence), dysmenorrhoea scores (RR 2.25; 95% CI 1.59 to 3.16, 1 RCT, n = 85, low-certainty evidence), dyspareunia scores (RR 2.21; 95% CI 1.39 to 3.54, 1 RCT, n = 59, low-certainty evidence), and pelvic tenderness scores (RR 2.28; 95% CI 1.48 to 3.50, 1 RCT, n = 85, low-certainty evidence) after three months of treatment. We are uncertain of the effect for pelvic induration, based on the results found after three months of treatment (RR 1.07; 95% CI 0.64 to 1.79, 1 RCT, n = 81, low-certainty evidence). Besides, treatment with GnRHas may be associated with a greater incidence of hot flushes at three months of treatment (RR 3.08; 95% CI 1.89 to 5.01, 1 RCT, n = 100, low-certainty evidence). Trials comparing GnRHas versus danazol For overall pain, for women treated with either GnRHas or danazol, a subdivision was made between pelvic tenderness, partly resolved and completely resolved. We are uncertain about the effect on relief of overall pain, when a subdivision was made for overall pain (MD -0.30; 95% CI -1.66 to 1.06, 1 RCT, n = 41, very low-certainty evidence), pelvic pain (MD 0.20; 95% CI -0.26 to 0.66, 1 RCT, n = 41, very low-certainty evidence), dysmenorrhoea (MD 0.10; 95% CI -0.49 to 0.69, 1 RCT, n = 41, very low-certainty evidence), dyspareunia (MD -0.20; 95% CI -0.77 to 0.37, 1 RCT, n = 41, very low-certainty evidence), pelvic induration (MD -0.10; 95% CI -0.59 to 0.39, 1 RCT, n = 41, very low-certainty evidence), and pelvic tenderness (MD -0.20; 95% CI -0.78 to 0.38, 1 RCT, n = 41, very low-certainty evidence) after three months of treatment. For pelvic pain (MD 0.50; 95% CI 0.10 to 0.90, 1 RCT, n = 41, very low-certainty evidence) and pelvic induration (MD 0.70; 95% CI 0.21 to 1.19, 1 RCT, n = 41, very low-certainty evidence), the complaints may decrease slightly after treatment with GnRHas, compared to danazol, for six months of treatment. Trials comparing GnRHas versus analgesics  We did not identify any studies. Trials comparing GnRHas versus intra-uterine progestogens We did not identify any low risk of bias studies. Trials comparing GnRHas versus GnRHas in conjunction with calcium-regulating agents There may be a slight decrease in bone mineral density (BMD) after 12 months treatment with GnRHas, compared to GnRHas in conjunction with calcium-regulating agents for anterior-posterior spine (MD -7.00; 95% CI -7.53 to -6.47, 1 RCT, n = 41, very low-certainty evidence) and lateral spine (MD -12.40; 95% CI -13.31 to -11.49, 1 RCT, n = 41, very low-certainty evidence).  AUTHORS' CONCLUSIONS: For relief of overall pain, there may be a slight decrease in favour of treatment with GnRHas compared to placebo or oral or injectable progestogens. We are uncertain about the effect when comparing GnRHas with danazol, intra-uterine progestogens or gestrinone. For BMD, there may be a slight decrease when women are treated with GnRHas, compared to gestrinone. There was a bigger decrease of BMD in favour of GnRHas, compared to GnRHas in conjunction with calcium-regulating agents. However, there may be a slight increase in adverse effects when women are treated with GnRHas, compared to placebo or gestrinone. Due to a very low to low certainty of the evidence, a wide range of outcome measures and a wide range of outcome measurement instruments, the results should be interpreted with caution.

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.

Minimising menopausal side effects whilst treating endometriosis and fibroids

Medical management of endometriosis and fibroids involves manipulation of the hypothalamic-pituitary-gonadal axis to alter the balance of sex hormones thereby inhibiting disease progression and ameliorate symptoms. Unfortunately, resultant menopausal symptoms sometimes limit the tolerability and duration of such treatment. The use of gonadotrophin-releasing hormone agonists to treat these diseases can result in short-term hypoestrogenic and vasomotor side effects as well as long-term impacts on bone health and cardiovascular risk. The routine use of add-back hormone replacement has reduced these risks and increased patient compliance, making this group of drugs more useful as a medium-term treatment option. The estrogen threshold hypothesis highlights the concept of a 'therapeutic window' in which bone loss is minimal but the primary disease is not aggravated. It explains why add-back therapy is appropriate for such patients and helps to explain the basis behind new developments in the treatment of hormonally responsive gynaecological conditions such as gonadotrophin-releasing hormone antagonists and progesterone receptor modulators.

Triptorelin for the treatment of endometriosis

INTRODUCTION

Over the past 30 years, gonadotropin-releasing hormone agonists (GnRH-a) have been used to induce a hypoestrogenic status in women with endometriosis with the aim to cause an improvement in pain symptoms similar to that observed after menopause. Triptorelin is one of the most commonly used GnRH-a.

AREAS COVERED

This review offers an explanation of the mechanism of action, of the pharmacokinetics and pharmacodynamics of triptorelin and gives the readers a complete overview of the studies on the clinical efficacy, tolerability and safety of this agent in patients with endometriosis.

EXPERT OPINION

The studies reviewed in the current manuscript demonstrate the efficacy of triptorelin in improving pain symptoms caused by endometriosis. Further, this effect is confirmed by the reduction in the volume of the endometriotic nodules during treatment. Future research should evaluate whether the pre-operative administration of triptorelin prior to surgical excision of endometriomas may be useful in preserving the ovarian reserve.

ESHRE guideline: management of women with endometriosis

STUDY QUESTION

What is the optimal management of women with endometriosis based on the best available evidence in the literature?

SUMMARY ANSWER

Using the structured methodology of the Manual for ESHRE Guideline Development, 83 recommendations were formulated that answered the 22 key questions on optimal management of women with endometriosis.

WHAT IS KNOWN ALREADY

The European Society of Human Reproduction and Embryology (ESHRE) guideline for the diagnosis and treatment of endometriosis (2005) has been a reference point for best clinical care in endometriosis for years, but this guideline was in need of updating.

STUDY DESIGN, SIZE, DURATION

This guideline was produced by a group of experts in the field using the methodology of the Manual for ESHRE Guideline Development, including a thorough systematic search of the literature, quality assessment of the included papers up to January 2012 and consensus within the guideline group on all recommendations. To ensure input from women with endometriosis, a patient representative was part of the guideline development group. In addition, patient and additional clinical input was collected during the scoping and review phase of the guideline.

PARTICIPANTS/MATERIALS, SETTING, METHODS

NA.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 83 recommendations on diagnosis of endometriosis and on the treatment of endometriosis-associated pain and infertility, on the management of women in whom the disease is found incidentally (without pain or infertility), on prevention of recurrence of disease and/or painful symptoms, on treatment of menopausal symptoms in patients with a history of endometriosis and on the possible association of endometriosis and malignancy.

LIMITATIONS, REASONS FOR CAUTION

We identified several areas in care of women with endometriosis for which robust evidence is lacking. These areas were addressed by formulating good practice points (GPP), based on the expert opinion of the guideline group members.

WIDER IMPLICATIONS OF THE FINDINGS

Since 32 out of the 83 recommendations for the management of women with endometriosis could not be based on high level evidence and therefore were GPP, the guideline group formulated research recommendations to guide future research with the aim of increasing the body of evidence.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the implementation of the guideline. The guideline group members did not receive payment. All guideline group members disclosed any relevant conflicts of interest (see Conflicts of interest).

TRIAL REGISTRATION NUMBER

NA.

Gonadotropin-releasing hormone agonist and add-back therapy: what do the data show?

PURPOSE OF REVIEW

Endometriosis is a gynecologic disorder that can lead to debilitating chronic pelvic pain and infertility. Gonadotropin-releasing hormone agonists (GnRHa) have emerged as a primary medical therapy for patients with symptomatic disease, but secondary hypoestrogenic side effects may limit compliance. Add-back therapy is a means of surmounting this problem.

RECENT FINDINGS

Progestins such as norethindrone acetate may be administered with or without addition of low doses of estrogens to safely and effectively extend GnRHa therapy while minimizing side effects. Recent studies have demonstrated that the use of add-back enhances compliance and duration of therapy. The initiation of an add-back should not be deferred given evidence demonstrating an increase in vasomotor symptoms and bone loss if not administered concomitantly. The subset of adolescents with endometriosis who require GnRHa therapy should be administered an add-back, but require careful monitoring of bone mineral density.

SUMMARY

Implementation of an appropriately selected add-back will significantly reduce hypoestrogenic side effects, enhance compliance, and allow for prolongation of therapy without interfering with the efficacy of GnRHa in treating symptomatic endometriosis.

Hormone therapy for endometriosis and surgical menopause

BACKGROUND

Endometriosis is characterized by the presence of ectopic endometrial tissue that might lead to many distressing and debilitating symptoms. Despite available studies supporting standard hormone therapy for women with endometriosis and post-surgical menopause, there is still a concern that estrogens may induce a recurrence of the disease and its symptoms.

OBJECTIVES

This review aimed to look at pain and disease recurrence in women with endometriosis who used hormone therapy for post-surgical menopause.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialized Register (March 2008), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 3), MEDLINE (1966 to March 2008), EMBASE (1980 to March 2008), and references lists of articles. Relevant journals and conference proceedings were handsearched.

SELECTION CRITERIA

Randomized controlled trials studying hormone therapy for women with endometriosis in post-surgical menopause.

DATA COLLECTION AND ANALYSIS

Review authors assessed the eligibility of trials and their quality.

MAIN RESULTS

Two studies fulfilled our inclusion criteria. One trial compared the nonstop transdermal application of 17beta-estradiol (0.05 mg/day) combined with cyclic medroxy progesterone acetate (10 mg per day) for 12 days per month in women with a conserved uterus with nonstop tibolone (2.5 mg/day). The second trial used sequential administration of estrogens and progesterone with two 22 cm(2) patches applied weekly to produce a controlled release of 0.05 mg/day. Micronized progesterone was administered orally (200 mg/day) for 14 days with a 16-day interval free of treatment. Pain and dyspareunia The first trial reported recurrence of pain in the estrogen and progesterone arm in 4/10 of women compared with 1/11 in the tibilone arm. In the latter, 4/115 women reported recurrence of pain in the treatment group compared with 0/57 patients in the no-treatment arm. Neither finding was statistically different.Confirmed recurrence or exacerbation of endometriosis This outcome was not reported in the first trial. The second found that 2/115 of the treatment group developed recurrence of endometriosis with no recurrence reported in the no-treatment group. This was not statistically significant. No woman was re-operated on in the no-treatment group compared with 2/115 in the treatment group.

AUTHORS' CONCLUSIONS

Hormone replacement therapy for women with endometriosis in post-surgical menopause could result in pain and disease recurrence. However, the evidence in the literature is not strong enough to suggest depriving severely symptomatic patients from this treatment. There is a need for more randomised controlled studies.

WITHDRAWN: Gonadotrophin-releasing hormone analogues for pain associated with endometriosis

BACKGROUND

Endometriosis is a common gynaecological condition that frequently presents with the symptom of pain. The precise pathogenesis (mode of development) of endometriosis is unclear but it is evident that endometriosis arises by the dissemination of endometrium to ectopic sites and the subsequent establishment of deposits of ectopic endometrium. The observation that endometriosis is rarely seen in the hypo-oestrogenic (low levels of oestrogen) post-menopausal woman led to the concept of medical treatment by induction of a pseudo-menopause using Gonadotrophin Releasing Hormone Analogues (GnRHas). When administered in a non-pulsatile manner (the pituitary is normally stimulated by pulses of natural GnRH and all analogues act on the pituitary at a constant level) their use results in down regulation (switching off) of the pituitary and a hypogonadotrophic hypogonadal state (low levels of female hormones due to non stimulation of the ovary).

OBJECTIVES

To determine the effectiveness of Gonadotrophin Releasing Hormone analogues (GnRHas) in the treatment of the painful symptoms of endometriosis by comparing them with no treatment, placebo, other recognised medical treatments, and surgical interventions.

SEARCH STRATEGY

The search strategy of the Menstrual Disorders and Subfertility review group (please see Review Group details) was used to identify all randomised trials of the use of GnRHas for the treatment of the painful symptoms of endometriosis.

SELECTION CRITERIA

Trials were included if they were randomised, and considered the effectiveness of GnRHas in the treatment of the painful symptoms of endometriosis.

DATA COLLECTION AND ANALYSIS

Twenty-six studies had data appropriate for inclusion in the review. The largest group (15 studies) compared GnRHas with danazol. There are five studies comparing GnRHas with GnRHas plus add-back therapy, three comparing GnRHa with GnRHa in a different form or dose, one compares them with gestrinone, one with the combined oral contraceptive pill, and one with placebo. Data was extracted independently by two reviewers. The authors of eleven studies have been contacted to clarify missing or unclear data. Only four have replied to date. Data on relief of pain, change in revised American Fertility Society (rAFS) scores, and side effects was collected.

MAIN RESULTS

No difference was found between GnRHas and any of the other active comparators with respect to pain relief or reduction in endometriotic deposits. The side effect profiles of the different treatments were different, with danazol and gestrinone having more androgenic side effects, while GnRHas tend to produce more hypo-oestrogenic symptoms.

AUTHORS' CONCLUSIONS

There is little or no difference in the effectiveness of GnRHas in comparison with other medical treatments for endometriosis. GnRHas do appear to be an effective treatment. Differences that do exist relate to side effect profiles. Side effects of GnRHas can be ameliorated by the addition of addback therapy.

Optimizing gonadotropin-releasing hormone agonist therapy in women with endometriosis

Endometriosis is a highly prevalent disease among women of reproductive age. While many treatments are available, one of the most widely utilized is treatment with gonadotropin-releasing hormone (GnRH) agonists. These agents work by producing a profound suppression of gonadotropin secretion by the pituitary, resulting in a hypoestrogenic state and subsequent diminution of endometriosis lesions. The GnRH agonists on the market have been shown to work quite well in reducing all pain symptoms associated with endometriosis, including dysmenorrhea, dyspareunia, and noncyclic pelvic pain. However, there is no evidence to suggest that this treatment is of value in endometriosis-associated infertility. Conflicting data exist regarding the role of GnRH agonists in the treatment of endometriomas, but the bulk of the evidence suggests a low degree of efficacy. GnRH agonists are often initiated with the onset of menses, but a more rapid response is observed with mid-luteal administration. A limit of 6 months per treatment course is required due to loss of bone mineral density during therapy, but this can be extended via the addition of 'add-back' therapy. Such adjunctive regimens demonstrated to maintain efficacy and reduce adverse effects include progestogen alone or a low-dose combination of estrogen and progestogen. Retreatment with these drugs is supported by limited data. The use of GnRH agonists as surgical adjuncts has been studied by several investigators. Their use preoperatively has not been shown to be of value. Similarly, 3 months of postoperative administration has failed to enhance treatment. However, 6 months of postoperative GnRH agonists appear to improve the duration of relief of pain symptoms. Future studies will need to focus on the role of these agents when used for repeated courses, in young women, and in conjunction with assisted reproduction.

Effect of gonadotropin-releasing hormone agonist and medroxyprogesterone acetate on calcium metabolism: a prospective, randomized, double-blind, placebo-controlled, crossover trial

OBJECTIVE

The purpose of this study was to prospectively compare the effectiveness of administering medroxyprogesterone acetate (MPA; 20 mg/d) in either the first (protocol A) or last (protocol B) 12-week period as well as a 6-month course of the GnRH agonist (GnRH-a; leuprolide acetate; 1 mg/d, SC) on calcium (Ca) metabolism.

DESIGN

Prospective, randomized, double-blind, placebo-controlled, crossover trial.

SETTING

Clinical research center, university hospital.

PATIENT(S)

Twenty women were randomized into protocol A or B, received either MPA or placebo along with GnRH-a, and were then crossed over at 12 weeks to placebo or MPA, for the final 12-week interval of GnRH-a therapy.

INTERVENTION(S)

Collection of serum and urine samples and measurement of bone density. Sex hormone, calcitropic hormone, and bone density studies were performed at baseline and at 12 and 24 weeks.

RESULT(S)

In both protocol A and B, LH and E(2) levels declined by 79%-81% and 83%-90% of the baseline, respectively, at 12 and 24 weeks. Serum Ca, phosphorus, alkaline phosphatase, and osteocalcin; 2-h fasting and 24-h urinary Ca excretion; and urinary hydroxyproline levels all increased significantly during GnRH-a treatment alone. Estimated Ca balance decreased significantly during GnRH-a treatment alone. The addition of MPA attenuated the increases in phosphorus, alkaline phosphatase, osteocalcin, and 2-h fasting and 24-h urinary Ca excretion, and the decrease in estimated Ca balance. Comparison of phase order demonstrated that MPA prevented 24-h urinary Ca excretion and urinary hydroxyproline loss and decline in estimated Ca balance when it was added back during the second 12 weeks (protocol B) but not during the first 12 weeks (protocol A). CONCLUSION (S): We conclude that sequential MPA appears to reverse in part the negative effects of GnRH-a on calcitropic hormones and estimated Ca balance.

Consensus statement for the management of chronic pelvic pain and endometriosis: proceedings of an expert-panel consensus process

OBJECTIVE

To develop recommendations for the medical and surgical care of women who present with chronic pelvic pain (CPP) and are likely to have endometriosis as the underlying cause.

DESIGN

An expert panel comprised of practicing gynecologists from throughout the United States and experts in consensus guideline development was convened. After completion of a structured literature search and creation of draft algorithms by an executive committee, the expert panel of >50 practicing gynecologists met for a 2-day consensus conference during which the clinical recommendations and algorithms were reviewed, refined, and then ratified by unanimous or near-unanimous votes.

PATIENT(S)

Women presenting with CPP who are likely to have endometriosis as the underlying cause.

MAIN OUTCOME MEASURE(S)

None.

CONCLUSION(S)

Chronic pelvic pain frequently occurs secondary to nongynecologic conditions that must be considered in the evaluation of affected women. For women in whom endometriosis is the suspected cause of the pain, laparoscopic confirmation of the diagnosis is unnecessary, and a trial of medical therapy, including second-line therapies such as danazol, GnRH agonists, and progestins, is justified provided that there are no other indications for surgery such as the presence of a suspicious adnexal mass. When surgery is necessary, laparoscopic approaches seem to offer comparable clinical outcomes to those performed via laparotomy, but with reduced morbidity. The balance of evidence supports the use of adjuvant postoperative medical therapy after conservative surgery for CPP. There is some evidence that adjuvant presacral neurectomy adds benefit for midline pain, but currently, there is inadequate evidence to support the use of uterosacral nerve ablation or uterine suspension. Hysterectomy alone has undocumented value in the surgical management of women with endometriosis-associated CPP.

The treatment of endometriosis: a review of the evidence

The treatment of endometriosis focuses upon amelioration of two symptoms: pain and infertility. The treatment of endometriosis-associated pain has been well studied and all major medical therapies appear to be superior to placebo. In addition, none seems to be drastically better than another. Surgical therapy also appears to be efficacious, albeit with a relatively high rate of recurrence of symptoms following conservative surgical intervention. There are no trials comparing the relative value of medical versus surgical therapy. Combination surgery/medical therapy has several high-quality trials for evaluation, but its value remains unclear. The treatment of endometriosis-associated infertility presents a different picture: medical therapy has not been shown to be of any value and may prove detrimental to fertility. Surgical treatment does improve fertility, probably for all stages of disease. Assisted reproduction also seems to be efficacious, with both controlled ovarian hyperstimulation and intrauterine insemination as well as in vitro fertilization shown to be of benefit. Finally, the combination of in vitro fertilization and either medical or surgical therapy may be beneficial with advanced endometriosis, but further study is required.

Conventional medical therapies for endometriosis

Endometriosis is a common gynecologic disorder that affects approximately 14% of all women and 30% to 50% of infertile women. Since the most common symptoms of endometriosis--progressive dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility--are also symptoms of multiple disorders, a diagnosis of endometriosis can be elusive and confirmed only by visualization, that is, laparoscopy. Endometriosis is often treated surgically upon diagnosis; however, the rate of recurrence is high, suggesting that a combination of therapeutic approaches might provide better outcomes than any one option alone. The most widely utilized hormonal treatments for endometriosis are GnRH agonists and oral contraceptives; agents indicated by the Food and Drug Administration include GnRH agonists and the androgen, danazol. The majority of evidence in support of medical therapy for endometriosis is largely observational, with the exception of studies of GnRH agonists, danazol, and a few progestins. Conventional treatment approaches for the medical management of endometriosis focus on suspected endometriosis, following a diagnosis of endometriosis, following surgical treatment of endometriosis, long-term management, and retreatment. Although major advances have been made in the treatment of endometriosis in recent decades, lack of randomized clinical trials evaluating the use of agents such as oral contraceptives alone or as add-back therapy for GnRH agonists, or those that examine combined medical and surgical treatments, has hampered the ability of physicians to provide the broadest range of medical therapies for this disorder. Future trials addressing these issues are warranted.

Gonadotropin-releasing hormone agonist plus "add-back" hormone replacement therapy for treatment of endometriosis: a prospective, randomized, placebo-controlled, double-blind trial

OBJECTIVE

To assess the effect of add-back therapy with continuous combined estrogen-progestin on the GnRH agonist-induced hypoestrogenic state and its effectiveness in healing of endometriotic lesions.

DESIGN

A prospective, randomized, placebo-controlled, double-blind trial.

SETTING

Multiple centers in The Netherlands.

PATIENT(S)

41 premenopausal women with laparoscopically diagnosed endometriosis (revised American Fertility Society scores >/=2).

INTERVENTION(S)

Patients were randomly assigned to receive a subcutaneous depot formulation of goserelin, 3. 6 mg, every 4 weeks, plus oral placebo or oral continuous combined estradiol-norethisterone acetate add-back therapy daily for 24 weeks.

MAIN OUTCOME MEASURE(S)

Endometriosis response, bone mineral density, transvaginal ultrasonographic changes, endocrinologic effects, and subjective side effects.

RESULT(S)

The number of endometriotic implants was significantly reduced in both groups. In the group that received GnRH agonist plus placebo, bone mineral density of the lumbar spine decreased by 5.02%.

CONCLUSION(S)

The effectiveness of GnRH agonist treatment for endometriosis was not decreased by the addition of add-back continuous combined hormone replacement therapy. Bone mineral density of the lumbar spine was maintained and subjective side effects were diminished.

Clinical pharmacokinetics of goserelin

Goserelin is a synthetic decapeptide analogue of luteinising hormone-releasing hormone (LHRH). For experimental purposes it has been administered subcutaneously as an aqueous solution, but for therapeutic use it is formulated as subcutaneous depots releasing goserelin over periods of 1 (3.6 mg) or 3 (10.8 mg) months. Pharmacokinetic data have been generated using a specific radioimmunoassay. When administered as a solution, goserelin is rapidly absorbed and eliminated from serum with a mean elimination half-life (t1/2beta) of 4.2 hours in males and 2.3 hours in females. The shapes of the observed serum goserelin profiles following administration of the depots are primarily determined by the rate of goserelin release from the biodegradable lactide-glycolide copolymer matrix over periods of 1 or 3 months. There is no clinically relevant accumulation of goserelin during multiple administration of these depots. Goserelin is extensively metabolised prior to excretion. Its pharmacokinetics are unaffected by hepatic impairment, but the mean t1/2beta increases to 12.1 hours in patients with severe renal impairment. This suggests that the total renal clearance (renal metabolism and unchanged drug) is decreased in patients with renal dysfunction. It is unnecessary to adjust the dose or administration interval when the depot formulations are administered to elderly patients or to those with impaired renal or hepatic function. Administration of a goserelin 3.6 mg or 10.8 mg depot results in an initial increase of luteinising hormone (LH) levels and in increases of serum testosterone or oestradiol levels in males and females, respectively. This is followed by a decrease in serum LH levels and suppression of testosterone or oestradiol to within the castrate or menopausal range, respectively. Subsequently, throughout treatment with goserelin depots, serum testosterone or oestradiol levels remain suppressed. Clinical outcomes following treatment of patients with prostate cancer, breast cancer and benign gynaecological conditions with goserelin are described briefly.

Treatment of endometriosis with a decreasing dosage of a gonadotropin-releasing hormone agonist (nafarelin): a pilot study with low-dose agonist therapy ("draw-back" therapy)

OBJECTIVE

To evaluate the efficacy of half-dose GnRH agonist therapy for endometriosis.

DESIGN

Prospective, longitudinal pilot study.

SETTING

Osaka University Hospital.

PATIENT(S)

Patients with symptomatic endometriosis.

INTERVENTION(S)

Fifteen patients were randomized to receive either full-dose nafarelin treatment (200 microgram b.i.d.) for 24 weeks (n = 7) or full-dose nafarelin treatment for 4 weeks followed by half-dose nafarelin treatment (200 microgram daily) for 20 weeks (n = 8).

MAIN OUTCOME MEASURE(S)

Clinical symptoms and the results of physical examinations. Serum E(2) and carcinoma antigen 125 (CA125) levels, lipid profiles, and urinary levels of the N-telopeptide of type I collagen. Bone mineral density of the lumbar spine.

RESULT(S)

Subjective and objective manifestations of endometriosis were decreased to a similar extent in both study groups. Adverse effects were markedly reduced with half-dose administration. In the half-dose group, the mean serum E(2) level was significantly suppressed by 4 weeks of treatment with full-dose nafarelin and remained at approximately 30 pg/mL with half-dose nafarelin. Loss of bone mineral density was significantly less with half-dose treatment.

CONCLUSION(S)

Half-dose administration of nafarelin after pituitary down-regulation with full-dose nafarelin ("draw-back" therapy) is a new protocol for the treatment of endometriosis that is effective and associated with fewer adverse effects.

Add-back therapy and gonadotropin-releasing hormone agonists in the treatment of patients with endometriosis: can a consensus be reached? Add-Back Consensus Working Group

OBJECTIVE

To reach a consensus on the role of add-back therapy for patients with endometriosis administered GnRH agonists (GnRH-a).

DESIGN

Results of consensus conference reviewing MEDLINE search of English language abstracts of both prospective and retrospective series.

SETTING

Consensus conference of 31 specialists in gynecologic surgery and reproductive endocrinology.

PATIENT(S)

Patients with symptomatic endometriosis who were candidates for GnRH-a therapy in treatment courses ranging in duration from 6 to 12 months.

INTERVENTION(S)

Oral steroidal and nonsteroidal add-back regimens.

MAIN OUTCOME MEASURE(S)

Alteration in painful symptoms, extent of disease, vasomotor symptoms, bone mineral density, and serum lipid profile.

RESULT(S)

When added to GnRH-a for 6 months, both 2.5 mg of norethindrone and 0.625 mg of conjugated equine estrogens with 5 mg/d of medroxyprogesterone acetate provide effective relief of vasomotor symptoms and decrease but do not eliminate bone mineral density loss. During 12 months of GnRH-a therapy, bone mineral density loss is eliminated effectively with an add-back of 5 mg of norethindrone acetate alone or in conjunction with low-dose conjugated equine estrogens. Organic bisphosphonates also may play a role.

CONCLUSION(S)

In patients with symptomatic endometriosis, the efficacy of GnRH agonists may be preserved and therapy prolonged while overcoming hypoestrogenic side effects with the use of appropriate add-back regimens.

The evidence for the management of endometriosis

This review article has focussed on identifying the evidence from randomized controlled trials for the medical and surgical management of endometriosis. A critical summary of the medical management has shown that there is little difference in effectiveness of various medical treatments, but there are differences in the side-effect profiles. Few randomized controlled trials have been undertaken in surgery, but these have shown that surgical management is effective in the management of both painful symptoms and subfertility.

Progestins for symptomatic endometriosis: a critical analysis of the evidence

OBJECTIVE

To obtain estimates of the effects of progestin treatment for pelvic pain associated with endometriosis.

DATA IDENTIFICATION

Information from studies published in the English-language literature between 1966 and 1996 was pooled. Articles were identified through hand and computerized searches using MEDLINE.

STUDY SELECTION

A total of 27 trials that were published in peer-reviewed journals were identified, and 13 of these were excluded from the analysis because of methodologic limitations. Nine of the remaining 14 studies were noncomparative (8 prospective and 1 retrospective), 1 was quasi-randomized, and 4 were true randomized controlled trials.

DATA EXTRACTION AND SYNTHESIS

The sample size was generally limited; the mean number of patients included was 26 in the noncomparative trials and 29 in the randomized controlled trials. The mean duration of treatment was 6 months. A total of 355 women had pain at entry. Considering all noncomparative studies, the pooled frequency of nonresponders at the end of treatment was 9% (18/203; 95% confidence interval [CI], 5.3% to 13.6%). The common odds ratio from the four randomized controlled trials comparing progestins with danazol or a GnRH agonist was 1.1 (95% CI, 0.4 to 3.1), suggesting equivalence in treatment effect. In the only double-blind, placebo-controlled trial, the frequency of nonresponders was not significantly different in the two arms. Only four studies assessed pain after drug withdrawal. The pooled frequency of pelvic pain at the end of follow-up was 50% (35/70; 95% CI, 37.8% to 62.2%). The overall crude conception rate after therapy among women who desired pregnancy was 44% (86/194; 95% CI, 37.2% to 51.6%). Side effects of limited clinical relevance were observed frequently.

CONCLUSION(S)

The available data suggest that the efficacy of progestins for temporary relief of endometriosis-associated pelvic pain is good and comparable to that of other, less safe treatments.

Excretion of urinary N-telopeptides reflects changes in bone turnover during ovarian suppression and indicates individually variable estradiol threshold for bone loss

OBJECTIVE

To evaluate the effectiveness of N-telopeptides and E2 in monitoring bone turnover during GnRH agonist- (GnRH-a) or danazol-induced hypoestrogenism.

DESIGN

Comparative, nonrandomized prospective study.

SETTING

Institute for the Study and Treatment of Endometriosis.

PATIENT(S)

Premenopausal women undergoing ovarian suppression with GnRH-a (n = 16) or danazol (n = 9).

INTERVENTION(S)

Serum and urine samples were collected and bone mineral density was measured before, during, and after treatment.

MAIN OUTCOME MEASURE(S)

N-telopeptide excretion, serum E2, and bone mineral density at L1 to L4 and femoral neck.

RESULT(S)

During treatment in the GnRH-a group, mean E2 levels were 53% below and N-telopeptides were 38% above the mean baseline. At 1 month post-treatment, L1 to L4 bone mineral density decreased by 3.85%. In the danazol group, E2, N-telopeptides and L1 to L4 bone mineral density changed nonsignificantly in the opposite direction with the mean 1.25% increase in L1 to L4 at 1 month post-treatment. In combined groups, L1 to L4 bone mineral density better correlated with other measures than femoral neck bone mineral density. N-telopeptide excretion was more predictive of L1 to L4 change, with correlation the highest between N-telopeptides at month 4 and bone mineral density at month 1 afterward, while E2 appeared more predictive of the less reliable femoral neck bone mineral density. Individual exceptions to the model of an E2 threshold for bone loss were observed. Also noted were high correlation between on-therapy levels of E2 and N-telopeptides, as well as the presence of a 1-month time lag between E2 and N-telopeptide changes.

CONCLUSION(S)

Bone density decreases during GnRH-a and may slightly increase during danazol treatment. However, E2 threshold for bone loss varies individually. N-telopeptides predict changes in bone mineral density at L1 to L4 better than E2.