Estroprogestinic pill normalizes IGF-I levels in acromegalic women

Role of Estrogen and Estrogen Receptor in GH-Secreting Adenomas

Acromegaly is a rare disease with several systemic complications that may lead to increased overall morbidity and mortality. Despite several available treatments, ranging from transsphenoidal resection of GH-producing adenomas to different medical therapies, complete hormonal control is not achieved in some cases. Some decades ago, estrogens were first used to treat acromegaly, resulting in a significant decrease in IGF1 levels. However, due to the consequent side effects of the high dose utilized, this treatment was later abandoned. The evidence that estrogens are able to blunt GH activity also derives from the evidence that women with GH deficiency taking oral estro-progestins pills need higher doses of GH replacement therapy. In recent years, the role of estrogens and Selective Estrogens Receptor Modulators (SERMs) in acromegaly treatment has been re-evaluated, especially considering poor control of the disease under first- and second-line medical treatment. In this review, we analyze the state of the art concerning the impact of estrogen and SERMs on the GH/IGF1 axis, focusing on molecular pathways and the possible implications for acromegaly treatment.

Managing Estrogen Therapy in the Pituitary Patient

Growth hormone (GH) regulates metabolic and physical health in the adult human. Because the GH system is regulated by estrogens, therapeutic estrogen compounds are likely to affect metabolic health. Estrogens are available for oral and parenteral use in natural, prodrug, and synthetic formulations including selective estrogen receptor modulators (SERMs). This review covers the pharmacology of estrogen and the effects on GH action to inform judicious use in the pituitary patient. The effects on the GH system are route dependent due to first-pass hepatic metabolism. Oral but not parenteral estrogen compounds inhibit GH action, reducing hepatic insulin-like growth factor-1 (IGF-1) production, protein anabolism, and fat utilization. In patients with GH deficiency, oral estrogen therapy exacerbates the degree of hyposomatotrophism and attenuates the beneficial effects of GH replacement therapy, effects that are greater with contraceptive than replacement doses. Surveys report that less than one-fifth of hypopituitary women are appropriately replaced by a transdermal route and up to half on oral therapy are inappropriately treated with contraceptive steroids. In acromegaly, however, estrogens, especially synthetic formulations of greater potency, reduce IGF-1, improving disease control, an effect also observed in men treated with SERMs. The route-dependent effects and potency of estrogen formulations are important considerations for optimizing the management of hypogonadal patients with pituitary disease, in particular GH deficiency and acromegaly. For hypopituitary women, estrogens should be replaced by a nonoral route. For acromegaly, oral estrogen formulations can be considered as simple adjuvant therapy for disease control.

A prospective study on the efficacy of oral estrogen in female patients with acromegaly

PURPOSE

To evaluate the efficacy and safety of oral estrogen therapy in female patients of childbearing age with uncontrolled acromegaly and to verify the significance of the presence of estrogen receptor α (ER-α) in somatotropinomas.

METHODS

Prospective study in which biochemical and radiological evaluations were performed at baseline and after six months of treatment with an oral formulation of ethinyl-estradiol 0.03 mg and levonorgestrel 0.15 mg. ER-α was assessed by immunohistochemistry and immunopositivity was considered when it was present in ≥ 1% of cells.

RESULTS

Eight patients with uncontrolled acromegaly were selected. All patients underwent surgery. Four patients were on octreotide LAR 30 mg, two patients were on lanreotide autogel 120 mg, and two patients had active disease after surgery. At the end of follow-up, IGF-I normalized in 3/8 (37%), 2/8 (25%) patients presented with mean IGF-I reduction of 25% but without IGF-I normalization, and 2/8 (25%) did not respond-one had a 13% increase in IGF-I and IGF-I level remained unchanged after treatment in the other. In one patient, treatment was discontinued after 3 months due to side effects (headache), with an IGF-I reduction of 28% but without normalization. Tumor volume increase (41%) was observed in only one patient (the only tumor with positive ER-α expression).

CONCLUSIONS

In uncontrolled patients with acromegaly, a trial with oral estrogen can be an option for young women. Oral estrogen was well tolerated, but the somatotropinoma that presented ER-α expression was the only somatotropinoma that presented growth during treatment.

Clinical features and therapeutic outcomes of patients with acromegaly in Saudi Arabia: a retrospective analysis

BACKGROUND

Acromegaly is a rare disease resulting in clinical sequelae with significant morbidity and mortality due to the central tumor mass effect and prolonged growth hormone (GH) hypersecretion.

OBJECTIVES

The goal is to describe the epidemiology, clinical features, presence of comorbidities, and treatment outcomes of acromegaly in Saudi Arabia.

METHODS

Data was collected through a retrospective review of the charts of all patients diagnosed with acromegaly from nine major hospitals in Saudi Arabia over a period of more than 25 years.

RESULTS

A total of 195 patients (116 males and 79 females), with a mean age at diagnosis of 43 ± 12 (males) and 46 ± 14 years (females), from nine major hospitals were identified and included in the analysis. All cases were caused by pituitary adenomas, of which 92.4% were macroadenomas. Headache, coarse facial features, acral growth, and sweating/oily skin were by far the most frequent presenting complaints. The most common comorbidities were diabetes mellitus (51.7%), followed by hypertension (50%) and visual field defect (30.5%). The vast majority (95%) of patients were treated surgically (98%). Twenty-four percent also received radiotherapy, and 74.4% received medical therapy. When stringent criteria were applied for assessment of outcomes of therapy, 28.7% of the patients were cured and 30.1% had their disease under control, while 28.7% were found to have active disease despite receiving multimodal therapy.

CONCLUSIONS

Our findings highlight the need for a national acromegaly registry to enable early identification, evaluation, and selection of the best therapeutic approaches to improve the outcome and remission rate of the disease.

Estrogens and selective estrogen receptor modulators in acromegaly

Despite recent advances in acromegaly treatment by surgery, drugs, and radiotherapy, hormonal control is still not achieved by some patients. The impairment of IGF-1 generation by estrogens in growth hormone deficient patients is well known. Patients on oral estrogens need higher growth hormone doses in order to achieve normal IGF-1 values. In the past, estrogens were one of the first drugs used to treat acromegaly. Nevertheless, due to the high doses used and the obvious side effects in male patients, this strategy was sidelined with the development of more specific drugs, as somatostatin receptor ligands and dopamine agonists. In the last 15 years, the antagonist of growth hormone receptor became available, making possible IGF-1 control of the majority of patients on this particular drug. However, due to its high cost, pegvisomant is still not available in many centers around the world. In this setting, the effect of estrogens and also of selective estrogen receptor modulators on IGF-1 control was reviewed, and proved to be an ancillary tool in the management of acromegaly. This review describes data concerning their efficacy and place in the treatment algorithm of acromegaly.

Estrogen and selective estrogen receptor modulators (SERMs) for the treatment of acromegaly: a meta-analysis of published observational studies

Estrogen and selective estrogen receptor modulator (SERM) treatments for acromegaly have received limited attention since the development of newer pharmacologic therapies. There has been ongoing research evidence suggesting their utility in the biochemical control of acromegaly. Therefore, the aim of this meta-analysis was to synthesise current evidence with a view to determining to what extent and in which acromegalic patient subsets do estrogen and SERMs reduce IGF-1 levels. A literature search was conducted (finished December 2012), which included all studies pertaining to estrogen or SERM treatment and IGF-1. Seven patient subsets were identified from six published observational studies, and were pooled using meta-analytic methods. Overall, the pooled mean loss in IGF-1 was -29.09 nmol/L (95 % CI -37.23 to -20.95). A sensitivity analysis indicated that women receiving estrogen had a substantially greater reduction in IGF-1 levels compared with women receiving SERMs, with a weighted mean loss in IGF-1 of -38.12 nmol/L (95 % CI -46.78 to -29.45) compared with -22.91 nmol/L (95 % CI -32.73 to -13.09). There was a trend that did not reach statistical significance for men receiving SERM treatment at -11.41 nmol/L (95 % CI -30.14 to 7.31). It was concluded that estrogen and SERMs are a low cost and effective treatment to achieve control of IGF-1 levels in acromegalic women either as concomitant treatment for refractory disease, or where access to conventional therapy is restricted. Their use in men requires further study.

Estrogen treatment for acromegaly

Estrogens have been used in patients with acromegaly since the 1930-1940s, suppressing plasma IGF-1 levels and improving clinical signs and symptoms of acromegaly. Estrogens antagonize GH function at the post-receptor level, inhibiting GH signaling, thus decreasing GH-induced hepatic IGF-1 synthesis. We report our experience with four female patients with active acromegaly, naïve to medical treatment or inadequately controlled by somatostatin receptor ligands (SRLs) or the GH-receptor antagonist. Adding estrogen treatment (contraceptive pills or transdermal estrogen patches) to their ongoing medical treatment, suppressed IGF-1 significantly in all patients, achieving hormonal remission in three of them. We review the available data on the use of estrogens and selective estrogen receptor modulators in acromegaly, and their mechanisms of action. Estrogens could be an alternative, inexpensive adjuvant treatment for females with active acromegaly, who are only partially responding to SRLs or to the GH-receptor antagonist.

Octreotide long-acting repeatable for acromegaly

Acromegaly remains a therapeutic challenge for the endocrinologist. Among the available therapeutic options, octreotide long-acting repeatable (Sandostatin(®) LAR(®), Novartis) plays a chief role, both as a primary therapy and as an adjuvant treatment after unsuccessful surgery. A plethora of papers and a meta-analysis have demonstrated its efficacy in: control of clinical picture; achievement of safe growth hormone and normal age-matched IGF-I levels (both factors associated with restoration of normal life expectancy) in 60-70% of patients; control of tumor volume (with real shrinkage in over half of cases); and halt or reversal of most acromegaly-associated comorbidities. Treatment is well tolerated in most patients and can be safely prolonged for many years if required.

Oral estroprogestin: an alternative low cost therapy for women with postoperative persistent acromegaly?

Oral estrogens reduce GH-induced IGF-1 production and preliminary studies have shown that adjuvant estroprogestin (EP) therapy with octreotide LAR may control disease activity in some female patients who are partially responsive to octreotide LAR. Our aim was to verify if EP alone or in combination with octreotide LAR can achieve remission of acromegaly in selected cases of patients uncontrolled by surgery. Eleven women with persistent active acromegaly following surgery participated in this unblinded open label pilot study. Their mean age was 49.8 ± 4.3 years. Two patients were drug naïve, two patients had stopped octreotide LAR because of intolerance and seven were treated with octreotide LAR. The patients received either EP (EP pill, 20 μg ethinylestradiol, 100 μg levonorgestrel) alone (4 patients) or added to octreotide LAR (7 patients). Fasting GH, IGF-1, glucose, HDL- and LDL-cholesterol, and triglycerides were measured at baseline and at last visit. MRI was controlled at baseline and at last visit. Duration of estrogen treatment was 3.1 ± 0.5 years. Serum IGF-1 levels were normalized in 8/11 patients (73%). Serum GH concentrations did not change significantly during treatment (11.6 ± 5.6 μg/L prior to EP vs 5.5 ± 1.2 μg/L following EP). In patients treated with EP alone, remission was achieved in 2/4 patients (IGF-1 percentages of the upper limit of normal age-matched range (%ULN): 211 ± 40% before EP compared to 95 ± 15% after EP, P = 0.028). In the seven patients treated by EP added to octreotide LAR, remission was achieved in 6 patients (IGF-1%ULN: 158 ± 9% before EP compared to 86 ± 4% after EP, P = 0.0003). Glucose and cholesterol levels were unchanged by EP treatment (data not shown). MRI did not show any evidence of tumour progression with EP in patients who had a tumour remnant. In conclusion, oral estrogen treatment appears to normalize serum IGF-1 concentrations in over 70% of women with acromegaly uncured by surgery irrespective of their sensitivity to octreotide LAR. We suggest that estrogens may be a temporary cost-effective and safe treatment for women with postoperative persistent acromegaly.

A consensus on criteria for cure of acromegaly

OBJECTIVE

The Acromegaly Consensus Group met in April 2009 to revisit the guidelines on criteria for cure as defined in 2000.

PARTICIPANTS

Participants included 74 neurosurgeons and endocrinologists with extensive experience of treating acromegaly. EVIDENCE/CONSENSUS PROCESS: Relevant assays, biochemical measures, clinical outcomes, and definition of disease control were discussed, based on the available published evidence, and the strength of consensus statements was rated.

CONCLUSIONS

Criteria to define active acromegaly and disease control were agreed, and several significant changes were made to the 2000 guidelines. Appropriate methods of measuring and achieving disease control were summarized.

Clinical and biochemical improvement in acromegaly during pregnancy

Numerous case reports of pregnancy in acromegaly exist, however detailed descriptions of changes in placental and pituitary GH and IGF-I throughout gestation are rare. A 19-yr-old female presented to this institution with signs and symptoms of a GH-secreting pituitary adenoma. Following transphenoidal hypophysectomy, she had 3 unplanned pregnancies, despite ongoing active disease. No pregnancy was complicated by glucose intolerance or hypertension and 3 healthy newborns were delivered near or at term. Clinical improvement was observed during each pregnancy, accompanied by IGF-I levels lower than in the non-pregnant state, the majority lying within the normal range. This was despite increasing placental GH levels, and was not consistent with previous reports in the literature. Further surgical and medical therapies for acromegaly failed to normalize nonpregnant GH or IGF-I levels in this woman. Estrogen is known to alter GH signaling via its interaction with Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. We hypothesize that increasing concentrations of estrogen or other pregnancy-related hormones resulted in her clinical and biochemical improvement during pregnancy. This may be used for future therapeutic benefit.

Octreotide for acromegaly

Octreotide has dramatically changed the results of medical treatment of acromegaly. It is the reference drug for the pharmacological treatment of acromegaly, owing to its impressive efficacy in suppressing growth hormome secretion, and excellent compliance. Safe growth hormone and normal insulin-like growth factor I values are reached in 50-60% of unselected patients. Octreotide arrests the growth of the tumor and shrinks tumor in over half of all patients (namely, up to 88% of naive patients and to complete disappearance in anecdotic cases). The safety profile of octreotide is excellent, but in some patients, glucose metabolism worsens and cholelythiasis occurs. This review will address the primary treatment and the relative roles of pharmacological and surgical treatment, as well as the predictivity of octreotide results.

Factors regulating growth hormone secretion in humans

Growth hormone (GH) secretion is pulsatile in nature in all species. The periodic pattern of GH release plays an important role in transmitting the GH message in a tissue-specific manner. The question of what regulates the pulsatile GH secretion pattern is an issue of not only theoretical interest but of considerable practical importance for designing different GH therapies for a variety of human diseases. This article provides a brief introductory overview of the different regulators of GH secretion and concentrates primarily on human studies.

Absence of the full-length breast cancer-associated gene-1 leads to increased expression of insulin-like growth factor signaling axis members

The breast cancer-associated gene-1 (BRCA1) plays many important functions in multiple biological processes/pathways. Mice homozygous for a targeted deletion of full-length BRCA1 (Brca1Delta11/Delta11) display both increased tumorigenesis and premature aging, yet molecular mechanisms underlying these defects remain elusive. Here, we show that Brca1 deficiency leads to increased expression of several insulin-like growth factor (IGF) signaling axis members in multiple experimental systems, including BRCA1-deficient mice, primary mammary tumors, and cultured human cells. Furthermore, we provide evidence that activation of IGF signaling by BRCA1 deficiency can also occur in a p53-independent fashion. Our data indicate that BRCA1 interacts with the IRS-1 promoter and inhibits its activity that is associated with epigenetic modification of histone H3 and histone H4 to a transcriptional repression chromatin configuration. We further show that BRCA1-deficient mammary tumor cells exhibit high levels of IRS-1, and acute suppression of Irs-1 using RNA interference significantly inhibits growth of these cells. Those observations provide a molecular insight in understanding both fundamental and therapeutic BRCA1-associated tumorigenesis and aging.

Modulation of the growth hormone-insulin-like growth factor (GH-IGF) axis by pharmaceutical, nutraceutical and environmental xenobiotics: an emerging role for xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. A review

The growth hormone-insulin-like growth factor (GH-IGF) axis has gained considerable focus over recent years. One cause of this increased interest is due to a correlation of age-related decline in plasma GH/IGF levels with age-related degenerative processes, and it has led to the prescribing of GH replacement therapy by some practitioners. On the other hand, however, research has also focused on the pro-carcinogenic effects of high GH-IGF levels, providing strong impetus for finding regimes that reduce its activity. Whereas the effects of GH/IGF activity on the action of xenobiotic-metabolizing enzyme systems is reasonably well appreciated, the effects of xenobiotic exposure on the GH-IGF axis has not received substantial review. Relevant xenobiotics are derived from pharmaceutical, nutraceutical and environmental exposure, and many of the mechanisms involved are highly complex in nature, not easily predictable from existing in vitro tests and do not always predict well from in vivo animal models. After a review of the human and animal in vivo and in vitro literature, a framework for considering the different levels of direct and indirect modulation by xenobiotics is developed herein, and areas that still require further investigation are highlighted, i.e. the actions of common endocrine disruptors such as pesticides and phytoestrogens, as well as the role of xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. It is anticipated that a fuller appreciation of the existing human paradigms for GH-IGF axis modulation gained through this review may help explain some of the variation in levels of plasma IGF-1 and its binding proteins in the population, aid in the prescription of particular dietary regimens to certain individuals such as those with particular medical conditions, guide the direction of long-term drug/nutraceutical safety trials, and stimulate ideas for future research. It also serves to warn athletes that using compounds touted as performance enhancing because they promote short-term GH release could in fact be detrimental to performance in the long-run.

Resistance to somatostatin analogs in acromegaly: an evolving concept?

The aim of acromegaly treatment is to control the disease by suppressing GH hyperactivity and reducing the size or impeding the growth of the pituitary GH secreting mass. Over recent years, many studies have emphasized the role of SS analogs in the treatment of acromegaly. In fact, SS analogs have been demonstrated to be an effective tool not only in the control of GH hypersecretion but also more recently in the control of tumor growth, in a relevant number of acromegalic patients both as primary or adjunctive treatment. In this context, the therapeutic failure of medical treatment with SS analogs needs to be accurately defined particularly when they are used as primary treatment but also when they are given to patients previously operated upon, since other effective therapeutic options are nowadays available. Current definition of resistance to SS analogs is based on their efficacy to control GH and IGF-I. However, due to the emerging significance of the shrinkage effect of SS analogs on pituitary adenomas as well as to the apparent dissociation between this effect and the biochemical effects of treatment with these analogs, an evolution in the concept of SS resistance is likely to be occurring. In this review, we will discuss the biological basis of the discordance between biochemical and volumetric effects of SS analogs, and we will address the intriguing clinical and therapeutic aspects related to a possible redefinition of the resistance to SS analogs.

Etiologic aspects and management of acromegaly

Acromegaly is a systemic disease with various etiologies. It can occur as a sporadic or, more rarely, as a familial disease. Numerous complications such as endocrine, cardiovascular, respiratory, metabolic, osteoarticular and neoplastic disturbances occur and must be taken into account when establishing a therapeutic strategy. For this reason, the decision as to a treatment modality of acromegaly must be followed by a thorough evaluation of the patient and once the diagnosis of complications is settled, adequate treatment should be instituted. Follow up of the patients requires periodical re-assessment of complications’ status.

Treatment of acromegaly with SS analogues: should GH and IGF-I target levels be lowered to assert a tight control of the disease?

BACKGROUND

in acromegaly, the criteria for the cure of the disease after neurosurgery have become tighter and tighter. In contrast, the evaluation of control of disease activity during medical treatment is based upon the normalisation of IGF-I levels and epidemiological criteria, i.e. lessening GH (assessed by RIA) to levels reported to normalise increased mortality. The aim of this study was to evaluate GH and IGF-I suppression during prolonged SS analogues (SA) treatment. The concordance between "safe" GH and normalised IGF-I levels during SA was also assessed, according to gender and gonadal status.

DESIGN

multicentre, retrospective. Patients. GH/IGF-I levels were evaluated in 207 acromegalic patients (132 females, aged 20-85 yr) during a prolonged treatment (longer than 12 months) with individually tailored doses of depot SA( lanreotide or octreotide-LAR in 97 and 110 patients, respectively). Final IGF-I levels were transformed in z-scores using data collected in a large cohort of normal subjects of 3 different age groups (20-40 yr old, 41-60 yr old, 61-80 yr old, n=160, 148, 115, respectively), that allowed to set up quartiles of normality (I = 3rd-25th percentile, II = 26th-50th, III = 51th-75th, IV = 76th-97th).

RESULTS

fifty-nine and 19.3% of patients achieved GH levels <2.5 and <1 microg/l, respectively. IGF-I were normalised (z-score between 2 and -2) in 58.4% of patients. The distribution of normal IGF-I values among quartiles was uneven: 7%, 19%, 25%, and 49% of values were distributed in the I, II, III, and IV quartile, respectively. The concordance between GH and IGF-I values was poor: 28.4% of patients attaining GH values <2.5 microg/l had still pathological IGF-I (even 12.5% of those with GH <1 microg/l), and 39.3% of those with GH levels still above the "safe" limit had "nor IGF-I. Although proportions of IGF-I normalisation were not different between males and females, the regression line obtained between GH and IGF-I z-score showed the same slope but with a significantly lower intercept in regularly cycling women than in males and in postmenopausal females. Thus for any GH value, cycling females had lower IGF-I than menopausal women and males, and their IGF-I normalisation could be achieved by higher GH values. By ROC analysis, the achievement of normal IGF-I was predicted by the GH value of 1.8 microg/l in males and 2.4 microg/l in females.

CONCLUSIONS

in acromegalic patients on SA treatment, GH and IGF-I levels are often not concordant. In addition to age, sex is to be taken into account in the evaluation of hormonal targets. A better refinement of GH and IGF-I targets to be reached while on treatment with SA is warranted.