Acromegaly

Position statement on the diagnosis and management of acromegaly: The French National Diagnosis and Treatment Protocol (NDTP)

Acromegaly is a rare disease with prevalence of approximately 60 cases per million, slight female predominance and peak onset in adults in the fourth decade. Clinical diagnosis is often delayed by several years due to the slowly progressive onset of symptoms. There are multiple clinical criteria that define acromegaly: dysmorphic syndrome of insidious onset, symptoms related to the pituitary tumor (headaches, visual disorders), general signs (sweating, carpal tunnel syndrome, joint pain, etc.), complications of the disease (musculoskeletal, cardiovascular, pneumological, dental, metabolic comorbidities, thyroid nodules, colonic polyps, etc.) or sometimes clinical signs of associated prolactin hypersecretion (erectile dysfunction in men or cycle disorder in women) or concomitant mass-induced hypopituitarism (fatigue and other symptoms related to pituitary hormone deficiencies). Biological confirmation is based initially on elevated IGF-I and lack of GH suppression on oral glucose tolerance test or an elevated mean GH on repeated measurements. In confirmed cases, imaging by pituitary MRI identifies the causal tumor, to best determine management. In a minority of cases, acromegaly can be linked to a genetic predisposition, especially when it occurs at a young age or in a familial context. The first-line treatment is most often surgical removal of the somatotroph pituitary tumor, either immediately or after transient medical treatment. Medical treatments are most often proposed in patients not controlled by surgical removal. Conformal or stereotactic radiotherapy may be discussed on a case-by-case basis, especially in case of drug inefficacy or poor tolerance. Acromegaly should be managed by a multidisciplinary team, preferably within an expert center such as a reference or skill center for rare pituitary diseases.

Real-world experience with pasireotide-LAR in resistant acromegaly: a single center 1-year observation

CONTEXT

Pasireotide-LAR, a second-generation somatostatin receptor ligand (SRL), is recommended for patients with acromegaly as second-line treatment. Its efficacy and safety were assessed in clinical trials; however, the real-world evidence is still scarce.

OBJECTIVE

The aim of this study was to evaluate the impact of 1-year treatment with pasireotide-LAR on disease control and glucose metabolism in acromegaly patients resistant to first-generation SRLs.

DESIGN

A single-center prospective study.

METHODS

Twenty-eight patients with active acromegaly or acrogigantism on first-generation SRLs following ineffective pituitary surgery were switched to treatment with pasireotide-LAR 40 or 60 mg i.m. every 28 days. To assess the efficacy of the treatment GH and IGF-1 levels were measured every 3 months. Safety of treatment was carefully evaluated, especially its impact on glucose metabolism.

RESULTS

Complete biochemical control (GH ≤ 1 ng/mL and IGF-1 ≤ 1 × ULN) was achieved in 26.9% of patients and partial + complete response (GH ≤ 2.5 ng/mL and IGF-1 ≤ 1.3 × ULN) in 50.0% of patients. Mean GH level decrease was the largest within first 6 months (P = 0.0001) and mean IGF-1 level decreased rapidly within the first 3 months (P < 0.0001) and they remained reduced during the study. Blood glucose and HbA1c levels increased significantly within 3 months (P = 0.0001) and stayed on stable level thereafter. Otherwise, the treatment was well tolerated and clinical improvement was noticed in majority of patients.

CONCLUSIONS

This real-life study confirmed good effectiveness of pasireotide-LAR in patients resistant to first-generation SRLs. Pasireotide-LAR was overall safe and well tolerated, however significant glucose metabolism worsening was noted.

Cost-Utility of Acromegaly Pharmacological Treatments in a French Context

Objective

Efficacy of pharmacological treatments for acromegaly has been assessed in many clinical or real-world studies but no study was interested in economics evaluation of these treatments in France. Therefore, the objective of this study was to estimate the cost-utility of second-line pharmacological treatments in acromegaly patients.

Methods

A Markov model was developed to follow a cohort of 1,000 patients for a lifetime horizon. First-generation somatostatin analogues (FGSA), pegvisomant, pasireotide and pegvisomant combined with FGSA (off label) were compared. Efficacy was defined as the normalization of insulin-like growth factor-1 (IGF-1) concentration and was obtained from pivotal trials and adjusted by a network meta-analysis. Costs data were obtained from French databases and literature. Utilities from the literature were used to estimate quality-adjusted life year (QALY).

Results

The incremental cost-utility ratios (ICUR) of treatments compared to FGSA were estimated to be 562,463 € per QALY gained for pasireotide, 171,332 € per QALY gained for pegvisomant, and 186,242 € per QALY gained for pegvisomant + FGSA. Pasireotide seems to be the least cost-efficient treatment. Sensitivity analyses showed the robustness of the results.

Conclusion

FGSA, pegvisomant and pegvisomant + FGSA were on the cost-effective frontier, therefore, depending on the willingness-to-pay for an additional QALY, they are the most cost-effective treatments. This medico-economic analysis highlighted the consistency of the efficiency results with the efficacy results assessed in the pivotal trials. However, most recent treatment guidelines recommend an individualized treatment strategy based on the patient and disease profile.

Clinical and hormonal findings in patients presenting with high IGF-1 and growth hormone suppression after oral glucose load: a retrospective cohort study

OBJECTIVE

High insulin-like growth factor 1 (IGF-1) and unsuppressed growth hormone (GH) levels after glucose load confirm the diagnosis of acromegaly. Management of patients with conflicting results could be challenging. Our aim was to evaluate the clinical and hormonal evolution over a long follow-up in patients with high IGF-1 but normal GH nadir (GHn < 0.4 μg/L according to the latest guidelines).

DESIGN

Retrospective cohort study.

METHODS

We enrolled 53 patients presenting high IGF-1 and GHn < 0.4 μg/L, assessed because of clinical suspicion of acromegaly or in other endocrinological contexts (e.g. pituitary incidentaloma). Clinical and hormonal data collected at the first and last visit were analyzed.

RESULTS

At the first evaluation, the mean age was 54.1 ± 15.4 years, 34/53 were females, median IGF-1 and GHn were +3.1 SDS and 0.06 μg/L, respectively. In the whole group, over a median time of 6 years, IGF-1 and GHn levels did not significantly change (IGF-1 mean of differences: -0.58, P = 0.15; GHn +0.03, P = 0.29). In patients with clinical features of acromegaly, the prevalence of acromegalic comorbidities was higher than in the others (median of 3 vs 1 comorbidities per patient, P = 0.005), especially malignancies (36% vs 6%, P = 0.03), and the clinical worsening overtime was more pronounced (4 vs 1 comorbidities at the last visit).

CONCLUSIONS

In patients presenting high IGF-1 but GHn < 0.4 μg/L, a hormonal progression is improbable, likely excluding classical acromegaly in its early stage. However, despite persistently low GH nadir values, patients with acromegalic features present more acromegalic comorbidities whose rate increases over time. Close clinical surveillance of this group is advised.

Clinical presentation and management of acromegaly in elderly patients

BACKGROUND AND AIM

Acromegaly is a rare disease with a peak of incidence in early adulthood. However, enhanced awareness of this disease, combined with wide availability of magnetic resonance imaging (MRI), has increased the diagnosis of forms with mild presentation, especially in elderly patients. Moreover, due to increased life expectancy and proactive individualized treatment, patients with early-onset acromegaly are today aging. The aim of our study was to describe our cohort of elderly patients with acromegaly.

MATERIALS AND METHODS

This is a cross-sectional retrospective study of 96 outpatients. Clinical, endocrine, treatment, and follow-up data were collected using the electronic database of the University Hospital of Padova, Italy.

RESULTS

We diagnosed acromegaly in 13 patients, aged ≥65 years, presenting with relatively small adenomas and low IGF-1 secretion. Among them, 11 patients were initially treated with medical therapy and half normalized hormonal levels after 6 months without undergoing neurosurgery (TNS). Remission was achieved after TNS in three out of four patients (primary TNS in two); ten patients presented controlled acromegaly at the last visit. Acromegaly-related comorbidities (colon polyps, thyroid cancer, adrenal incidentaloma, hypertension, and bone disease) were more prevalent in patients who had an early diagnosis (31 patients, characterized by a longer follow-up of 24 years) than in those diagnosed aged ≥65 years (5 years of follow-up).

CONCLUSIONS

Elderly acromegalic patients are not uncommon. Primary medical therapy is a reasonable option and is effectively used, while the rate of surgical success is not reduced. A careful cost-benefit balance is suggested. Disease-specific comorbidities are more prevalent in acromegalic patients with a longer follow-up rather than in those diagnosed aged ≥65 years.

Pharmacological Acromegaly Treatment: Cost-Utility and Value of Information Analysis

OBJECTIVES

To conduct a cost-utility analysis comparing drug strategies involving octreotide, lanreotide, pasireotide, and pegvisomant for the treatment of patients with acromegaly who have failed surgery, from a Brazilian public payer perspective.

METHODS

A probabilistic cohort Markov model was developed. One-year cycles were employed. The patients started at 45 years of age and were followed lifelong. Costs, efficacy, and quality of life parameters were retrieved from the literature. A discount rate (5%) was applied to both costs and efficacy. The results were reported as costs per quality-adjusted life year (QALY), and incremental cost-effectiveness ratios (ICERs) were calculated when applicable. Scenario analyses considered alternative dosages, discount rate, tax exemption, and continued use of treatment despite lack of response. Value of information (VOI) analysis was conducted to explore uncertainty and to estimate the costs to be spent in future research.

RESULTS

Only lanreotide showed an ICER reasonable for having its use considered in clinical practice (R$ 112,138/US$ 28,389 per QALY compared to no treatment). Scenario analyses corroborated the base-case result. VOI analysis showed that much uncertainty surrounds the parameters, and future clinical research should cost less than R$ 43,230,000/US$ 10,944,304 per year. VOI also showed that almost all uncertainty that precludes an optimal strategy choice involves quality of life.

CONCLUSIONS

With current information, the only strategy that can be considered cost-effective in Brazil is lanreotide treatment. No second-line treatment is recommended. Significant uncertainty of parameters impairs optimal decision-making, and this conclusion can be generalized to other countries. Future research should focus on acquiring utility data.

Cardiovascular complications of acromegaly

Acromegaly is a chronic disease due to growth hormone (GH) and insulin-like growth factor 1 (IGF-1) excess. It is associated with various systemic complications including cardiovascular disease. Arterial hypertension occurs in about 20% to 30% of patients. Its pathogenesis is mainly related to the increase in plasma volume secondary to a sodium retaining actions of GH and IGF-1 in the kidney, but abnormalities in vessel architecture and reactivity participate. Left ventricular hypertrophy and diastolic dysfunctions were frequently reported in echo-based studies and are mostly mild and without clinical consequences. Recent cardiac MRI studies described a much lower frequency of myocardial hypertrophy than echo-based assessments. Progression to systolic dysfunction with congestive heart failure is nowadays very rare. Risk of coronary heart disease and of clinically significant arrythmias does not seem to be increased. Acromegaly-related cardiac valve abnormalities may be related to fibrotic changes and seem to persist after effective treatment of acromegaly. Advances in acromegaly treatment over the last decades significantly diminished the cardiovascular burden of the disease, with the cardiovascular disease anymore being the leading cause of death.

Growth hormone and prolactin-staining tumors causing acromegaly: a retrospective review of clinical presentations and surgical outcomes

OBJECTIVE

Acromegaly results in disfiguring growth and numerous medical complications. This disease is typically caused by growth hormone (GH)-secreting pituitary adenomas, which are treated first by resection, followed by radiation and/or medical therapy if needed. A subset of acromegalics have dual-staining pituitary adenomas (DSPAs), which stain for GH and prolactin. Presentations and treatment outcomes for acromegalics with DSPAs are not well understood.

METHODS

The authors retrospectively reviewed the records of more than 5 years of pituitary adenomas resected at their institution. Data were collected on variables related to clinical presentation, tumor pathology, radiological size, and disease recurrence. The Fisher's exact test, ANOVA, Student t-test, chi-square test, and Cox proportional hazards and multiple logistic regression were used to measure statistical significance.

RESULTS

Of 593 patients with pituitary adenoma, 91 presented with acromegaly. Of these 91 patients, 69 (76%) had tumors that stained for GH only (single-staining somatotrophic adenomas [SSAs]), while 22 (24%) had tumors that stained for GH and prolactin (DSPAs). Patients with DSPAs were more likely to present with decreased libido (p = 0.012), signs of acromegalic growth (p = 0.0001), hyperhidrosis (p = 0.0001), and headaches (p = 0.043) than patients with SSAs. DSPAs presented with significantly higher serum prolactin (60.7 vs 10.0 µg/L, p = 0.0002) and insulin-like growth factor-1 (IGF-1) (803.6 vs 480.0 ng/ml, p = 0.0001), and were more likely to have IGF-1 levels > 650 ng/ml (n = 13 [81.3%] vs n = 6 [21.4%], p = 0.0001) than patients with SSAs despite similar sizes (1.8 vs 1.7 cm, p = 0.5). Patients with DSPAs under 35 years of age were more likely to have a recurrence (n = 4 [50.0%] vs n = 3 [11.1%], p = 0.01) than patients with SSAs under the age of 35. DSPA patients were less likely to achieve remission with surgery than SSA patients (n = 2 [20%] vs n = 19 [68%], p = 0.01). Univariate analysis identified single-staining tumors (p = 0.02), gross-total resection (p = 0.02), and tumor diameter (p = 0.05) as predictors of surgical remission. Multiple logistic regression demonstrated that SSAs (p = 0.04) were independently associated with surgical remission of acromegaly. Kaplan-Meier analysis revealed that DSPAs had more time until disease remission (p = 0.033).

CONCLUSIONS

Acromegalics with tumors that stain for prolactin and GH, which represented almost a quarter of acromegalics in this cohort, had more aggressive clinical presentations and postoperative outcomes than SSAs. Prolactin staining provides useful information for acromegalics undergoing pituitary surgery.

Patients' perspectives on acromegaly diagnostic delay: a qualitative study

Context Acromegaly has a substantial diagnostic delay associated with an increased risk of comorbidities and psychosocial deterioration. Qualitative methods which focus on the ways that individuals understand and relate to what they are experiencing are the best methods for exploring patients' perspectives. To the best of our knowledge, they have not been developed in the context of acromegaly. Objectives This study aimed to explore the experience of the diagnostic pathway of patients with acromegaly. Design We conducted a qualitative study, based on 20 face-to-face unstructured interviews in a third referral Endocrinology center. Participants, purposively selected until data saturation, were patients with acromegaly with diverse disease durations, types of treatment or associated comorbidities. The data were examined by thematic analysis. Results Our analysis found four themes: (i) what happened for patients before the diagnosis; (ii) what happened after; (iii) the style or type of doctor involved and (iv) patients' suggestions for limiting diagnostic delay. Our findings underlined the direct associations between diagnostic delay and the doctor-patient encounter, and the truly catastrophic experience of this disease, both before and after the diagnosis. Conclusions Diagnosis of acromegaly requires active medical involvement and awareness. Intervention of patient-experts in medical schools may help to be more aware of this disease. Endocrinologists caring for patients with acromegaly should also address the catastrophic dimension of the patient's experience and initiate the narrative to help them to put it into words for preventing harmful consequences such as social isolation and QoL impairment, but also anxiety or depression.

National acromegaly registries

Acromegaly is a rare disease, associated with multiple organs and systems damage. Thanks to implementation of registries, systematic data gathering, knowledge sharing and standardizing medical practices for optimal care greatly improved. Data concerning 19 national acromegaly registries are available, involving more than 16,000 patients. The weighted mean age of diagnosis is 45.2 years and seems stable over time. A macroadenoma is found in 75% of the cases. The proportion of patients operated (>80%) did not change along time. By contrast, use of radiotherapy has decreased while use of medical therapy increased. If judged on IGF-I levels, acromegaly is controlled in 61.3% of the patients. The disease control rate has improved over time. This is likely due to the development of medical treatment strategies. The collection of data about comorbidities in national registries is much less comprehensive than those about epidemiology, disease control or treatment strategies. The most reported comorbidities are arterial hypertension and diabetes. Data concerning mortality trends are controversial. It seems that cancer has become a leading cause of death in acromegaly patients in the last decade, period in which life expectancy improved, while cardiovascular mortality decreased. In conclusion, acromegaly registries offer a global view of the disease with no "a priori" assumptions. This is of outmost importance, because of the large amount of data and the huge number of associated comorbidities. This will help to establish guidelines for management of this rare disease.

Acromegaly

Acromegaly is characterized by increased release of growth hormone and, consequently, insulin-like growth factor I (IGF1), most often by a pituitary adenoma. Prolonged exposure to excess hormone leads to progressive somatic disfigurement and a wide range of systemic manifestations that are associated with increased mortality. Although considered a rare disease, recent studies have reported an increased incidence of acromegaly owing to better disease awareness, improved diagnostic tools and perhaps a real increase in prevalence. Acromegaly treatment approaches, which include surgery, radiotherapy and medical therapy, have changed considerably over time owing to improved surgical procedures, development of new radiotherapy techniques and availability of new medical therapies. The optimal use of these treatments will reduce mortality in patients with acromegaly to levels in the general population. Medical therapy is currently an important treatment option and can even be the first-line treatment in patients with acromegaly who will not benefit from or are not suitable for first-line neurosurgical treatment. Pharmacological treatments include somatostatin receptor ligands (such as octreotide, lanreotide and pasireotide), dopamine agonists and the growth hormone receptor antagonist pegvisomant. In this Primer, we review the main aspects of acromegaly, including scientific advances that underlie expanding knowledge of disease pathogenesis, improvements in disease management and new medical therapies that are available and in development to improve disease control.

An update on clinical care for pregnant women with acromegaly

INTRODUCTION

As pregnancy is rare in women with acromegaly, only case reports and few series have been published.

AREAS COVERED

All case reports and publications dealing with pregnancy in patients with acromegaly were collated. Information concerning the effects of acromegaly on pregnancy outcomes, the impact of pregnancy on GH/IGF-I measurements, acromegaly comorbidity and pituitary adenoma size, the effects of treatment of acromegaly on fetus outcomes were retrieved and analyzed.

EXPERT COMMENTARY

Based on the small number of reported cases, pregnancy is generally uneventful, except for a potential increased incidence of gestational hypertension and diabetes mellitus. Medical therapy of acromegaly (dopamine agonists, somatostatin analogs, growth hormone-receptor antagonists) is generally interrupted before or at diagnosis of pregnancy. In very rare patients with a pituitary adenoma, particularly a macroadenoma that has not been surgically treated before pregnancy, or if a surgical remnant persists, or when acromegaly is revealed during pregnancy, tumor volume may increase and cause symptoms through a mass effect. Close monitoring of clinical manifestations and imaging are necessary during pregnancy in these cases. In the rare cases of symptomatic tumor enlargement during pregnancy, medical treatment with dopamine agonists or eventually somatostatin analogs may be attempted before resorting to transsphenoidal surgery.

Changes in metabolic parameters and cardiovascular risk factors after therapeutic control of acromegaly vary with the treatment modality. Data from the Bicêtre cohort, and review of the literature

CONTEXT

Untreated acromegaly is associated with increased morbidity and mortality due to malignant, cardiovascular, and cerebrovascular disorders. Effective treatment of acromegaly reduces excess mortality, but its impact on cardiovascular risk factors and metabolic parameters are poorly documented.

AIM

We analyzed changes in cardiovascular risk factors and metabolic parameters in patients receiving various treatment modalities.

PATIENTS AND METHODS

We retrospectively studied 96 patients with acromegaly, both at diagnosis and after IGF-I normalization following surgery alone (n = 51) or medical therapy with first generation somatostatin analogues (SSA, n = 23), or pegvisomant (n = 22). Duration of follow-up was 77 (42-161) months, 75 (42-112) months, and 62 (31-93) months, in patients treated with surgery alone, SSA, and pegvisomant, respectively. In all the cases except four, patients treated medically had underwent previous unsuccessful surgery.

RESULTS

IGF-I normalization was associated with increased body weight, decreased systolic blood pressure (SBP) in hypertensive patients, decreased fasting plasma glucose (FPG) and HOMA-IR and HOMA-B levels, increased HDL cholesterol (HDLc); whereas, LDL cholesterol (LDLc) was not significantly different. Plasma PCSK9 levels were unchanged in patients with available values. Cardiovascular and metabolic changes varied with the treatment modality: surgery, but not pegvisomant, had a beneficial effect on SBP; FPG decreased after surgery but increased after SSA; the decline in HOMA-IR was only significant after surgery; pegvisomant significantly increased LDLc and total cholesterol; whereas SA increased HDLc and had no effect on LDLc levels.

CONCLUSION

Treatments used to normalize IGF-I levels in patients with acromegaly could have differential effects on cardiovascular risk factors and metabolic parameters.

Effectiveness and safety of pegvisomant: a systematic review and meta-analysis of observational longitudinal studies

PURPOSE

Acromegaly is a rare disease that often requires drug treatment to achieve control, with pegvisomant being one of the most widely used therapies. In the present paper, we aimed to obtain evidence regarding the effectiveness and safety of pegvisomant by reviewing real-world observational longitudinal studies.

METHODS

A systematic review was performed with a meta-analysis of event rates (95% confidence interval (CI)) using a random effects model. Sensitivity and subgroup analyses were performed (comprehensive meta-analysis 2.0). The systematic review was performed in accordance to preferred reporting items for systematic reviews and meta-analyses, meta-analysis of observational studies in epidemiology, and Cochrane recommendations (PROSPERO register CRD 42017059880). PubMed, Scopus, Web of Science, and SciELO were used to search for literature. Observational studies in patients using pegvisomant for the treatment of acromegaly were included.

RESULTS

Initially, 552 papers were retrieved from the databases; and 31 articles were included in the qualitative analysis and 14 in the quantitative analysis. Eight primary meta-analyses were performed. The overall rate of patients with disease control was of 60.9% (51.8-69.3%; 95% CI). When considering patients under monotherapy, the control rate was 71.7% (64.0-78.4%; 95% CI). Tumor growth was estimated in 7.3% (4.7-11.1%; 95% CI) and elevation of transaminases in 3.0% (1.7-5.2%; 95% CI).

CONCLUSIONS

The real-world data showed that the effectiveness of pegvisomant is not as high as reported in interventional studies. Acromegaly appears to be better controlled when pegvisomant is used as a monotherapy. No serious adverse events were associated with the use of pegvisomant; however, given the high cost of this drug, further studies are required.

Signs and symptoms of acromegaly at diagnosis: the physician's and the patient's perspectives in the ACRO-POLIS study

PURPOSE

Acromegaly is characterized by a broad range of manifestations. Early diagnosis is key to treatment success, but is often delayed as symptomatology overlaps with common disorders. We investigated sign-and-symptom associations, demographics, and clinical characteristics at acromegaly diagnosis.

METHODS

Observational, cross-sectional, multicenter non-interventional study conducted at 25 hospital departments in France that treat acromegaly (ClinicalTrials.gov: NCT02012127). Adults diagnosed with acromegaly < 5 years were enrolled. Demographic and clinical data were obtained from medical reports and patient questionnaires. Sign-and-symptom associations were assessed by multiple correspondence analysis (MCA).

RESULTS

Overall, 472 patients were included in the analyses. MCA was unsuccessful in identifying sign-and-symptom associations at diagnosis. Endocrinologists (29.5% patients) and other clinical specialists (37.2% patients) were commonly first to suspect acromegaly. Morphologic manifestations (83.7-87.9% patients), snoring syndrome (81.4% patients), and asthenia (79.2% patients) were frequently present at diagnosis; differences were found between sexes for specific manifestations. Rates of discrepancy between patient- and physician-reported manifestations were highest for functional signs. Earliest manifestations prior to diagnosis, according to how they were detected, were enlarged hands and feet (6.4 ± 6.8 and 6.2 ± 6.9 years, functional signs), hypertension (6.6 ± 7.5 years, complementary examination) and carpal/cubital tunnel syndrome (5.7 ± 6.7 years, functional signs with complementary examination).

CONCLUSIONS

Results confirm the broad range of manifestations at diagnosis and delay in recognizing the disease. We identified early manifestations and sex differences that may aid physicians in diagnosing acromegaly. Discrepancy rates suggest physicians should obtain the patient's perspective and seek functional signs during diagnosis.

A designed cell-penetrating human SOCS2 protein suppresses GH-dependent cancer cell proliferation

Suppressor of cytokine signaling (SOCS) 2, a negative regulator of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), which is associated with acromegaly and cancers, is a promising candidate molecule for treating various diseases. To facilitate its use in protein therapy, we designed and constructed a human SOCS2 protein containing a membrane-permeable peptide sequence and expressed it in an Escherichia coli system. The partially purified recombinant protein was effectively delivered into several cancer cell lines and inhibited cell growth. Biochemical analysis showed that the recombinant SOCS2 protein interacted with growth hormone receptor (GHR) and downregulated GH-STAT5 signaling target genes. Our results suggest that the designed cell-penetrating SOCS2 protein will be useful in intercellular protein therapy to cure cancers. Abbreviations: SOCS: suppressor of cytokine signaling; GH: growth hormone; GHR: growth hormone receptor; IGF-1: insulin-like growth factor 1; CP: cell-penetrating; STAT: signal transducer and activator of transcription; JAK: Janus kinase; HNF: hepatocyte nuclear factor; MTM: membrane-translocating motif; HIV: human immunodeficiency virus.

Classification of Patients With GH Disorders May Vary According to the IGF-I Assay

CONTEXT

Insulinlike growth factor I (IGF-I) measurement is essential for the diagnosis and management of growth hormone (GH) disorders. However, patient classification may vary substantially according to the assay technique.

OBJECTIVE

We compared individual patient data and classifications obtained with six different IGF-I assay kits in a group of patients with various GH disorders.

DESIGN

In this cross-sectional study, we measured IGF-I with six immunoassays in 102 patients with active or treated acromegaly or GH deficiency. IGF-I normative data previously established for the same six assay kits were used to classify the patients (high, low, or normal IGF-I levels), using both raw data and standard deviation scores (SDSs). Pairwise concordance between assays was assessed with Bland-Altman plots and with the percentage of observed agreement and the weighted κ coefficient for categorized IGF-I SDS.

RESULTS

We observed marked variability both across each individual's IGF-I raw data and across IGF-I SDS values obtained with each of the six immunoassays. Pairwise concordance between assay values, as assessed with the weighted κ coefficient, ranged from 0.50 (moderate) to 0.81 (excellent).

CONCLUSION

Even when using normative data obtained in the same large population of healthy subjects and when using calculated IGF-I SDSs, agreement among IGF-I assay methods is only moderate to good. Differences in assay performance must be taken into account when evaluating and monitoring patients with GH disorders. This argues for the use of the same IGF-I assay for a given patient throughout follow-up.

Changes in the management and comorbidities of acromegaly over three decades: the French Acromegaly Registry

CONTEXT

Acromegaly is a rare disease associated with chronic multisystem complications. National registries have been created in several countries.

DESIGN

The French Registry contains data on acromegaly epidemiology, management and comorbidities recorded over more than three decades, retrospectively until 1999 and prospectively from 1999 to 2012.

RESULTS

Data could be analyzed for 999 of the 1034 patients included in the registry (46% males). Disease control, defined as IGF-I normalization (adjusted for age and sex), was achieved in 75% of patients at the last follow-up visit. Half the patients with uncontrolled disease had IGF-I levels below 1.5 times the upper limit of normal (ULN). The proportion of patients with surgically cured disease did not change markedly over time, whereas the proportion of patients with uncontrolled disease fell and the proportion of patients with medically controlled disease rose. Cardiovascular, metabolic, respiratory and rheumatologic comorbidities and their outcomes were recorded for most patients, and no noteworthy overall deterioration was noted over time. Cancer occurred in 10% of patients, for a standardized incidence ratio of 1.34 (95% CI: 0.94-1.87) in men and 1.24 (0.77-1.73) in women. Forty-one patients died during follow-up, for a standardized mortality ratio of 1.05 (0.70-1.42). Most deaths were due to cancer.

CONCLUSIONS

The majority of patients with acromegaly now have successful disease control thanks to the multistep management. The incidence of comorbidities following diagnosis of acromegaly is very low. Life expectancy is now close to that of the general population, probably owing to better management of the GH/IGF-I excess and comorbidities.

Cabergoline in acromegaly

Acromegaly, a rare disease due to growth hormone (GH) hypersecretion by a pituitary adenoma, is associated with severe comorbidity and premature death if not adequately treated. The usual first-line treatment is surgery. Various drugs, including somatostatin receptor ligands, dopamine agonists and GH receptor antagonists, are now available for use if surgery fails to suppress GH/IGF-I hypersecretion. Cabergoline, now the preferred dopamine agonist for treating hyperprolactinemia, is also used off-label for treating acromegaly. Cabergoline monotherapy is reported to normalize IGF-I levels in more than one-third of patients with acromegaly. When a somatostatin receptor ligand proves ineffective, cabergoline add-on therapy normalizes the IGF-I level in 40-50% of patients. Finally, when combined with the GH receptor antagonist pegvisomant in patients with mild uncontrolled disease, cabergoline helps to achieve normal IGF-I levels while avoiding the need for high-dose pegvisomant. Cabergoline is also inexpensive and well tolerated; in particular, it does not appear to promote heart valve disease.

In vitro impact of pegvisomant on growth hormone-secreting pituitary adenoma cells

Pegvisomant (PEG), an antagonist of growth hormone (GH)-receptor (GHR), normalizes insulin-like growth factor 1 (IGF1) oversecretion in most acromegalic patients unresponsive to somatostatin analogs (SSAs) and/or uncontrolled by transsphenoidal surgery. The residual GH-secreting tumor is therefore exposed to the action of circulating PEG. However, the biological effect of PEG at the pituitary level remains unknown. To assess the impact of PEG in vitro on the hormonal secretion (GH and prolactin (PRL)), proliferation and cellular viability of eight human GH-secreting tumors in primary cultures and of the rat somatolactotroph cell line GH4C1. We found that the mRNA expression levels of GHR were characterized in 31 human GH-secreting adenomas (0.086 copy/copy β-Gus) and the GHR was identified by immunocytochemistry staining. In 5/8 adenomas, a dose-dependent inhibition of GH secretion was observed under PEG with a maximum of 38.2±17% at 1μg/mL (P<0.0001 vs control). A dose-dependent inhibition of PRL secretion occurred in three mixed GH/PRL adenomas under PEG with a maximum of 52.8±11.5% at 10μg/mL (P<0.0001 vs control). No impact on proliferation of either human primary tumors or GH4C1 cell line was observed. We conclude that PEG inhibits the secretion of GH and PRL in primary cultures of human GH(/PRL)-secreting pituitary adenomas without effect on cell viability or cell proliferation.

Medical Treatment of Acromegaly with Dopamine Agonists or Somatostatin Analogs

Treatment of acromegaly aims to correct (or prevent) tumor compression of surrounding tissues by excising the disease-causing lesion and reduce growth hormone (GH) and IGF-1 levels to normal values. When surgery (the usual first-line treatment) fails to correct GH/IGF-1 hypersecretion, medical treatment with dopamine agonists (DAs; particularly cabergoline) or somatostatin analogs (SAs) can be used. The GH receptor antagonist pegvisomant is helpful in patients who are totally or partially resistant to SAs and can be given in association with both SAs and/or DAs. Thanks to this multistep therapeutic strategy, adequate hormonal disease control is achieved in most patients, giving them normal life expectancy. Comorbidities associated with acromegaly generally improve after treatment, but persistent sequelae may nonetheless impair quality of life.

Pegvisomant treatment in patients with acromegaly in clinical practice: The French ACROSTUDY

OBJECTIVE

To monitor long-term pegvisomant treatment of patients with acromegaly in routine clinical practice.

PATIENTS AND METHODS

The French ACROSTUDY is part of the global ACROSTUDY, an observational post-authorization safety surveillance study of acromegaly treatment with pegvisomant.

RESULTS

The median duration of follow-up of the 292 included patients was 5.2 years. Overall 272 (93%) patients received somatostatin analogues before initiation of pegvisomant. The most prescribed initial dose of pegvisomant (after possible administration of a loading dose) was 10mg/day and, starting from the 2nd year, the median dose was 20mg/day. Serum IGF-1 concentration decreased as soon as pegvisomant was started and after 5 years there was a 62% mean decrease in serum IGF-1 concentration. The percentage of patients with serum IGF-1 concentration within normal ranges (for age and sex) of the local laboratory shifted from 11% at start of pegvisomant to 43% at 6 months and 63% after 5 years. The last available imaging (242 patients) showed an increased or decreased tumor size in 4 and 10% of patients, respectively. Mean weight increased by 3 kg over the 5-year period (P<10(-3)). Mean fasting blood glucose significantly decreased over time (P<0.05), while HbA1c level remained unchanged. Tolerance profile was generally good and similar to that described in clinical studies.

CONCLUSION

This analysis showed a significant decrease in IGF-1 levels throughout the follow-up period, and confirmed that pegvisomant treatment is safe in acromegaly. The results of this interim analysis remain to be confirmed by the final analysis.

Long-term effects of pegvisomant on comorbidities in patients with acromegaly: a retrospective single-center study

CONTEXT

The effect of pegvisomant on IGF1 levels in patients with acromegaly is well documented, but little is known of its long-term impact on comorbidity.

AIM

The aim of this retrospective study was to evaluate the effects of long-term pegvisomant therapy on cardiorespiratory and metabolic comorbidity in patients with acromegaly.

PATIENTS AND METHODS

We analyzed the long-term (up to 10 years) effect of pegvisomant therapy given alone (n=19, 45%) or in addition to somatostatin analogues and/or cabergoline (n=23, 55%) on echocardiographic, polysomnographic and metabolic parameters in respectively 42, 12 and 26 patients with acromegaly followed in Bicêtre hospital.

RESULTS

At the first cardiac evaluation, 20±16 months after pegvisomant introduction, IGF1 levels normalized in 29 (69%) of the 42 patients. The left ventricular ejection fraction (LVEF) improved significantly in patients whose basal LVEF was ≤60% and decreased in those whose LVEF was >70%. The left ventricular mass index (LVMi) decreased from 123±25 to 101±21 g/m(2) (P<0.05) in the 17 patients with a basal LVMi higher than the median (91 g/m(2)), while it remained stable in the other patients. Pegvisomant reduced the apnoea-hypopnea index and cured obstructive sleep apnea (OSA) in four of the eight patients concerned. Long-term follow-up of 22 patients showed continuing improvements in cardiac parameters. The BMI and LDL cholesterol level increased minimally during pegvisomant therapy, and other lipid parameters were not modified.

CONCLUSIONS

Long-term pegvisomant therapy not only normalizes IGF1 in a large proportion of patients but also improves cardiac and respiratory comorbidity.

Medical combination therapies in Cushing's disease

INTRODUCTION

There has been growing interest on medical therapy for the management of Cushing's disease (CD), particularly in cases of persistent or recurrent hypercortisolism. Ketoconazole, an inhibitor of adrenal steroidogenesis, is the most widely used drug, whereas cabergoline and pasireotide are the most promising centrally acting agents. The main purpose of this review article is to highlight the options of medical treatment for CD, with a special emphasis on combination therapies, a topic that has only been addressed by a limited number of studies.

CONCLUSIONS

According to the results of these studies, combination therapies involving medications with additive or synergistic effects on ACTH and cortisol secretion seem quite attractive as they yield higher probability of longterm control of the hypercortisolism at lower doses, a lower incidence of side-effects, and possibly a lower rate of treatment escapes. Currently, ketoconazole, cabergoline, and pasireotide are the best drugs to be prescribed in combination.