Executive summary of the expert consensus document from the Spanish Society of Neurosurgery and the Spanish Society of Endocrinology and Nutrition: Clinical recommendations on the perioperative management of pituitary tumors

Pituitary tumors (PT) account for 15% of intracranial tumors affect 10.7%-14.4% of the population although the incidence of clinically relevant PT is 5.1 cases/100,000 inhabitants. Surgical treatment is indicated in PTs with hormone hypersecretion (except for prolactin-producing PTs) and those with local compressive or global neurological symptoms. Multidisciplinary care, is essential for patients with PTs, preferably delivered in a center of excellence and based on a well-defined care protocol. In order to facilitate and standardize the clinical procedures for this type of tumor, this document gathers the positioning of the Neuroendocrinology Knowledge Area of the Spanish Society of Endocrinology and Nutrition (SEEN) and the Spanish Society of Neurosurgery (SENEC) on the management of patients with PTs and their preoperative, surgical and postoperative follow-up.

Executive summary of the expert consensus document from the Spanish Society of Neurosurgery and the Spanish Society of Endocrinology and Nutrition: clinical recommendations on the perioperative management of pituitary tumors

Pituitary tumors (PT) account for 15% of intracranial tumors affect 10.7-14.4% of the population although the incidence of clinically relevant PT is 5.1 cases/100,000 inhabitants. Surgical treatment is indicated in PTs with hormone hypersecretion (except for prolactin-producing PTs) and those with local compressive or global neurological symptoms. Multidisciplinary care, is essential for patients with PTs, preferably delivered in a center of excellence and based on a well-defined care protocol. In order to facilitate and standardize the clinical procedures for this type of tumor, this document gathers the positioning of the Neuroendocrinology Knowledge Area of the Spanish Society of Endocrinology and Nutrition (SEEN) and the Spanish Society of Neurosurgery (SENEC) on the management of patients with PTs and their preoperative, surgical and postoperative follow-up.

Hypopituitarism after traumatic brain injury in adults: Clinical guidelines of the neuroendocrinology area of the Spanish Society of Endocrinology and Nutrition (SEEN)

Traumatic brain injury (TBI) is associated with hypopituitarism with a variable incidence, depending on the time and methods used to diagnosis, and on factors related to the trauma, such as its severity, its anatomical location and the drugs used in the acute phase. The pituitary gland can be damaged directly by the impact or secondary to factors such as ischemia, inflammation, excitotoxicity or immunity. In acute phases ACTH deficiency is the most relevant, since failure to detect and treat it can compromise the patient's life. Clinical manifestations are typical of each hormone deficient axes, although the combination hypopituitarism-trauma has been associated with cognitive deterioration, worse metabolic profile and greater impairment of quality of life. One of the clinical challenges is to determine which patients benefit from a systematic hormonal evaluation, and therefore from hormone replacement, and what is the appropriate time to do so and the most suitable diagnostic methods.

Magnetic resonance imaging as a predictor of therapeutic response to pasireotide in acromegaly

OBJECTIVE

Hyperintensity signal in T2-weighted magnetic resonance imaging (MRI) has been related to better therapeutic response during pasireotide treatment in acromegaly. The aim of the study was to evaluate T2 MRI signal intensity and its relation with pasireotide therapeutic effectiveness in real-life clinical practice.

DESIGN, PATIENTS AND MEASUREMENTS

Retrospective multicentre study including acromegaly patients treated with pasireotide. Adenoma T2-weighted MRI signal at diagnosis was qualitatively classified as iso-hyperintense or hypointense. Insulin-like growth factor (IGF-I), growth hormone (GH) and tumour volume reduction were assessed after 6 and 12 months of treatment and its effectiveness evaluated according to baseline MRI signal. Hormonal response was considered 'complete' when normalization of IGF-I levels was achieved. Significant tumour shrinkage was defined as a volume reduction of ≥25% from baseline.

RESULTS

Eighty-one patients were included (48% women, 50 ± 1.5 years); 93% had previously received somatostatin receptor ligands (SRLs) treatment. MRI signal was hypointense in 25 (31%) and hyperintense in 56 (69%) cases. At 12 months of follow-up, 42/73 cases (58%) showed normalization of IGF-I and 37% both GH and IGF-I. MRI signal intensity was not associated with hormonal control. 19/51 cases (37%) presented a significant tumour volume shrinkage, 16 (41%) from the hyperintense group and 3 (25%) from the hypointense.

CONCLUSIONS

T2-signal hyperintensity was more frequently observed in pasireotide treated patients. Almost 60% of SRLs resistant patients showed a complete normalization of IGF-I after 1 year of pasireotide treatment, regardless of the MRI signal. There was also no difference in the percentage tumour shrinkage over basal residual volume between the two groups.

Implications of Heterogeneity of Epithelial-Mesenchymal States in Acromegaly Therapeutic Pharmacologic Response

Acromegaly is caused by excess growth hormone (GH) produced by a pituitary tumor. First-generation somatostatin receptor ligands (SRLs) are the first-line treatment. Several studies have linked E-cadherin loss and epithelial-mesenchymal transition (EMT) with resistance to SRLs. Our aim was to study EMT and its relationship with SRLs resistance in GH-producing tumors. We analyzed the expression of EMT-related genes by RT-qPCR in 57 tumors. The postsurgical response to SRLs was categorized as complete response, partial response, or nonresponse if IGF-1 was normal, had decreased more than 30% without normalization, or neither of those, respectively. Most tumors showed a hybrid and variable EMT expression profile not specifically associated with SRL response instead of a defined epithelial or mesenchymal phenotype. However, high SNAI1 expression was related to invasive and SRL-nonresponsive tumors. RORC was overexpressed in tumors treated with SRLs before surgery, and this increased expression was more prominent in those cases that normalized postsurgical IGF-1 levels under SRL treatment. In conclusion, GH-producing tumors showed a heterogeneous expression pattern of EMT-related genes that would partly explain the heterogeneous response to SRLs. SNAI1 and RORC may be useful to predict response to SRLs and help medical treatment decision making.

Acromegaly disease activity according to ACRODAT®, a cross-sectional study in Spain: ACROVAL study

OBJECTIVES

To evaluate disease activity status using the Acromegaly Disease Activity Tool (ACRODAT^®) in a cohort of Spanish acromegaly patients, to assess the relationship between the level of disease activity according to both ACRODAT^® and the physicians' clinical evaluation, and to study the potential discrepancies in the perception of symptoms between physicians and patients.

DESIGN

Multicenter, observational, descriptive and cross-sectional study.

METHODS

Disease activity was assessed in adult patients with acromegaly under pharmacological treatment during at least 6 months using ACRODAT^®.

RESULTS

According to ACRODAT^®, 48.2%, 31.8% and 20.0% of a total of 111 patients were classified as having a stable disease (S), mild disease activity (M-DA) and significant disease activity (S-DA) respectively. ACRODAT^® classification of disease activity significantly correlated with physicians' opinion, with a moderate inter-rater agreement and a specificity of 92.45% (PPV = 86.21%). No correlation was found between IGF-I levels and severity of symptoms or quality of life (QoL). A decision to take clinical action was significantly more frequent in S-DA and M-DA patients than S patients but no action was taken on 5 (22.7%) and 27 (77.1%) S-DA and M-DA patients, respectively CONCLUSIONS: ACRODAT^® detected disease activity in 51.8% of patients. Interestingly, although M-DA and S-DA patients were likely to be in the process of being controlled, action was not always taken on these patients. ACRODAT^® is a validated and highly specific tool that may be useful to routinely monitor acromegaly and to identify patients with non-obvious disease activity by incorporating "patient-centred" parameters like symptoms and QoL to the clinical evaluation of acromegaly.

Pituitary surgery in elderly patients: a safe and effective procedure

PURPOSE

The incidence of pituitary adenoma (PA) increases with age. Transsphenoidal surgery (TSS) in elderly patients is often considered to have greater risk compared to the younger population. The aim of this study is to compare surgical results, evolution and postoperative complications between elderly and young patients undergoing TSS.

METHODS

Retrospective review of patients undergoing TSS between 2011 and 2018 in our institution. Patients were divided into two cohorts: elderly (≥65 years) and non-elderly (<65 years). Characteristics and outcomes of both groups were compared at diagnosis, before surgery and for an average of 5.9 years of postoperative follow-up.

RESULTS

One hundred and twenty-five patients were included, 53 patients were ≥65 years (42%). The elderly patients were more likely to have non-functioning PA (NFPA) (90.5% vs. 45.8%, p: <0.01), a higher proportion of macroadenomas (92.4% vs. 77.8%, p = 0.029) and greater extrasellar extension (88.7% vs. 68.1%, p = 0.007). The elderly group also had more compressive symptoms (54.7% vs. 34.7%, p = 0.035) and hypopituitarism (66% vs. 47.2%, p = 0.029). Overall, surgical and endocrinological outcomes between the two groups were similar. Inpatient mortality in the elderly group was 1.8%. Regarding long-term outcomes, elderly patients had more postoperative hypopituitarism (67.9% vs. 45.8%, p = 0.03) with no differences in permanent diabetes insipidus, less residual tumours (24.5% vs. 40.3%, p = 0.019) and a higher rate of remission after surgery (71.7% vs. 52.8%, p = 0.034). When only NFPA cases were compared, the only significant difference was a higher frequency of macroadenomas in the elderly group.

CONCLUSIONS

Our results support the safety and efficacy of TSS in elderly patients with PA. Age should not be considered an exclusion criterion for TSS given that successful results can be achieved if an experienced pituitary team is available.

GFRα 1-2-3-4 co-receptors for RET Are co-expressed in Pituitary Stem Cells but Individually Retained in Some Adenopituitary Cells

The RET tyrosine kinase receptor is expressed by the endocrine somatotroph cells of the pituitary where it has important functions regulating survival/apoptosis. However, RET is also expressed by the GPS pituitary stem cells localized in a niche between the adenopituitary and the intermediate lobe. To bind any of its four ligands, RET needs one of four co-receptors called GFRα1-4. It has been previously shown that GFRα1 is expressed by somatotroph cells and acromegaly tumors. GFRα2 was shown to be expressed by pituitary stem cells. GFRα4 was proposed as not expressed in the pituitary. Here we study the RNA and protein expression of the four GFRα co-receptors for RET in rat and human pituitary. The four co-receptors were abundantly expressed at the RNA level both in rat and human pituitary, although GFRα4 was the less abundant. Multiple immunofluorescence for each co-receptor and β-catenin, a marker of stem cell niche was performed. The four GFRα co-receptors were co-expressed by the GPS cells at the niche colocalizing with β-catenin. Isolated individual scattered cells positive for one or other receptor could be found through the adenopituitary with low β-catenin expression. Some of them co-express GFRα1 and PIT1. Immunohistochemistry in normal human pituitary confirmed the data. Our data suggest that the redundancy of GFRα co-expression is a self-supportive mechanism which ensures niche maintenance and proper differentiation.

Unmasking a new prognostic marker and therapeutic target from the GDNF-RET/PIT1/p14ARF/p53 pathway in acromegaly

Background

Acromegaly is produced by excess growth hormone secreted by a pituitary adenoma of somatotroph cells (ACRO). First-line therapy, surgery and adjuvant therapy with somatostatin analogs, fails in 25% of patients. There is no predictive factor of resistance to therapy. New therapies are investigated using few dispersed tumor cells in acute primary cultures in standard conditions where the cells do not grow, or using rat pituitary cell lines that do not maintain the full somatotroph phenotype. The RET/PIT1/p14ARF/p53 pathway regulates apoptosis in normal pituitary somatotrophs whereas the RET/GDNF pathway regulates survival, controlling PIT1 levels and blocking p14ARF (ARF) and p53 expression.

Methods

We investigated these two RET pathways in a prospective series of 32 ACRO and 63 non-functioning pituitary adenomas (NFPA), studying quantitative RNA and protein gene expression for molecular-clinical correlations and how the RET pathway might be implicated in therapeutic success. Clinical data was collected during post-surgical follow-up. We also established new'humanized’ pituitary cultures, allowing 20 repeated passages and maintaining the pituitary secretory phenotype, and tested five multikinase inhibitors (TKI: Vandetanib, Lenvatinib, Sunitinib, Cabozantinib and Sorafenib) potentially able to act on the GDNF-induced RET dimerization/survival pathway. Antibody arrays investigated intracellular molecular pathways.

Findings

In ACRO, there was specific enrichment of all genes in both RET pathways, especially GDNF. ARF and GFRA4 gene expression were found to be opposing predictors of response to first-line therapy. ARF cut-off levels, calculated categorizing by GNAS mutation, were predictive of good response (above) or resistance (below) to therapy months later. Sorafenib, through AMPK, blocked the GDNF/AKT survival action without altering the RET apoptotic pathway.

Interpretation

Tumor ARF mRNA expression measured at the time of the surgery is a prognosis factor in acromegaly. The RET inhibitor, Sorafenib, is proposed as a potential treatment for resistant ACRO.

Fund

This project was supported by national grants from Agencia Estatal de Investigación (AEI) and Instituto Investigación Carlos III, with participation of European FEDER funds, to IB (PI150056) and CVA (BFU2016-76973-R). It was also supported initially by a grant from the Investigator Initiated Research (IIR) Program (WI177773) and by a non-restricted Research Grant from Pfizer Foundation to IB. Some of the pituitary acromegaly samples were collected in the framework of the Spanish National Registry of Acromegaly (REMAH), partially supported by an unrestricted grant from Novartis to the Spanish Endocrine Association (SEEN).

CVA is also supported from a grant of Medical Research Council UK MR/M018539/1.

Long-term outcome of multimodal therapy for giant prolactinomas

Giant prolactinomas are rare tumors characterized by their large size, compressive symptoms, and extremely high prolactin secretion. The aim of this study is to describe our experience with a series of 16 giant prolactinomas cases in terms of clinical presentation, therapeutic decisions, and final outcomes. Retrospective analysis of adult patients diagnosed with giant prolactinomas at the endocrine departments of three university tertiary hospitals. We included 16 patients (43.7 % women); mean age at diagnosis: 42.1 ± 21 years. The most frequent presentation was compressive symptoms. The delay in diagnosis was higher in women (median of 150 months vs. 12 in men; p = 0.09). The mean maximum tumor diameter at diagnosis was 56.9 ± 15.5 mm, and mean prolactin levels were 10,995.9 ± 12,157.8 ng/mL. Dopamine agonists were the first-line treatment in 11 patients (mean maximum dose: 3.9 ± 3.2 mg/week). Surgery was the initial treatment in five patients and the second-line treatment in six. Radiotherapy was used in four cases. All patients but one, are still with dopamine agonists. After a mean follow-up of 9 years, prolactin normalized in 7/16 patients (43.7 %) and 13 patients (81 %) reached prolactin levels lower than twice the upper limit of normal. Mean prolactin level at last visit: 79.5 ± 143 ng/mL. Tumor volume was decreased by 93.8 ± 11.3 %, and final maximum tumor diameter was 18.4 ± 18.8 mm. Three patients are actually tumor free. Giant prolactinomas are characterized by a large tumor volume and extreme prolactin hypersecretion. Multimodal treatment is frequently required to obtain biochemical and tumor control.

Safety of long-term treatment with Pegvisomant: analysis of Spanish patients included in global ACROSTUDY

PURPOSE

To evaluate the long-term safety of Pegvisomant (PEG) in the Spanish cohort of ACROSTUDY.

METHODS

As of July 2013, 199 Spanish patients were included in ACROSTUDY, a global non interventional safety PEG surveillance study. Patients were observed for safety, biochemical outcome and magnetic resonance imaging evaluations.

RESULTS

PEG was administered during an average period of 6.7 ± 2.1 years and a mean daily dose of 15.5 ± 7.5 mg. 48.2% of patients received PEG monotherapy. 90.9% of patients had received other medical treatment before PEG start. 195 adverse events (AEs) were reported in 88 patients (44.2%), and serious AEs were described in 31 patients (15.6%). There were no cases of liver tests >10 ULN, or permanent liver damage. Tumor size changes were locally reported in 61 cases (33.5%), with increases observed in 11 patients (6%). In acromegalic patients with diabetes mellitus a decrease in fasting serum glucose value was reported, reaching statistical significance after 1 and 4 years of treatment (-24.6 and -25.9 mg/dl, p = 0.04). After 60 months, normal or lower limit of normal (LLN) IGF-I levels were found in 67.9% of patients. 85.5% of patients showed an IGF-I normal or <LLN at any time after PEG start. Most patients with uncontrolled IGF-I levels were on submaximal PEG doses.

CONCLUSIONS

ACROSTUDY carried out with the Spanish cohort confirmed that PEG has a favorable safety and efficacy profile. The percentage of patients considered under control was similar to data reported globally and in other local ACROSTUDY results.

Long-term treatment with pegvisomant for acromegaly: a 10-year experience

BACKGROUND

Efficacy of the GH-receptor antagonist pegvisomant (PEG) has differed between preclinical and observational studies mainly due to dose adjustment and IGF-I normalization criteria. An escape phenomenon has also been described, but its definition and underlying causes have not been fully established.

OBJECTIVE

To re-evaluate the outcomes of long-term PEG in a series of previously published patients and analyse the escape phenomenon.

METHODS

We reviewed all patients with acromegaly resistant to SSA in whom PEG was started as monotherapy, who had been included in a previous publication. We prospectively evaluated 64 (56·3% women) from six tertiary care referral hospitals in Spain, for whom data as of June 2014 were available. Escape to PEG was defined as confirmed loss of biochemical control (IGF-I >1·2xULN), after at least 6 months of previous control with a stable dose of PEG.

RESULTS

Patients were followed up for 13·0 (5·9-34·8) years since diagnosis, and 9·0 (4·1-10·4) years since the first administration of PEG. Fifty-one (89·5%) patients had an adequate IGF-I control at the last follow-up visit, 9 of them without treatment. Tumour growth was reported in 6 of 64 cases (9·4%), none of whom had received prior radiotherapy (P = 0·011). Seven patients died during follow-up. We found 16 escapes in 10 patients (15·6%). We identified potential underlying causes in 9 cases (tumour regrowth, previous treatment modifications, concomitant menopause and change in testosterone administration). The reason was unknown in 7 escapes, which occurred in 6 patients (9·4%). All patients, except one, achieved subsequent biochemical control after treatment adjustment.

CONCLUSIONS

We reassure the efficacy and safety of long-term PEG. An escape phenomenon may occur, but it can be overcome by adjusting therapy.

Genetic Predictors of Response to Different Medical Therapies in Acromegaly

In the era of predictive medicine, management of diseases is evolving into a more personal and individualized approach, as more data are available regarding clinical, biochemical, radiological, molecular, histopathological, and genetic aspects. In the particular setting of acromegaly, which is a rare, chronic, debilitating, and disfiguring disease, an optimized approach deems even more necessary, especially because of an associated increased morbidity and mortality, the impact on patients' quality of life, and the increased cost of frequently necessary life-long treatments. In this paper, we review the available studies that address potential genetic influences on acromegaly, their role in the outcome, and response to treatments, as well as their contribution to the risk of developing side effects. We focus mainly on pharmacogenetic factors involved during treatment with dopamine agonists, somatostatin analogs, and pegvisomant. Specifically, mutations in dopamine receptors, somatostatin receptors, growth hormone receptors, and metabolic pathways involved in growth hormone action; polymorphisms in the insulin-like growth factor and the insulin-like growth factor binding proteins; and polymorphisms in other genes that may determine differences in the frequency of developing adverse events.

Update on prognostic factors in acromegaly: Is a risk score possible?

Certain clinical conditions and markers have recently been demonstrated to modify the natural history of acromegaly in affected patients. Thus, some clinical, histological, radiological and molecular factors are associated with more aggressive pituitary tumors that have higher biochemical activity, higher tumor volumes and decreased tumoral and biochemical responses to current therapies. However, these factors do not seem to have an equal influence on the prognosis of patients with acromegaly. We present a review of the factors that influence the clinical course of patients with acromegaly and propose a risk value for each factor that will allow prognostic scoring for affected patients by considering a combination of these factors.

Hypopituitarism after traumatic brain injury

The prevalence of hypopituitarism after traumatic brain (TBI) injury is widely variable in the literature; a meta-analysis determined a pooled prevalence of anterior hypopituitarism of 27.5%. Growth hormone deficiency is the most prevalent hormone insufficiency after TBI; however, the prevalence of each type of pituitary deficiency is influenced by the assays used for diagnosis, severity of head trauma, and time of evaluation. Recent studies have demonstrated improvement in cognitive function and cognitive quality of life with substitution therapy in GH-deficient patients after TBI.

Influence of the exon 3 deletion of GH receptor and IGF-I level at diagnosis on the efficacy and safety of treatment with somatotropin in adults with GH deficiency

PURPOSE

The treatment of adults with GH deficiency (GHD) with human recombinant growth hormone has interindividual variability and several factors influence it. The aims of this study were : 1-to analyze the GH receptor (GHR) genotype in terms of exon 3 deletion GHR (d3-GHR) in adults with GHD; 2-to assess the effects of d3-GHR on initial IGF-I levels; 3-to evaluate whether d3-GHR and/or initial IGF-I levels were associated with adverse effects and/or treatment discontinuation.

METHODS

Forty-four adult patients with GHD were included. Demographic, clinical and biochemical characteristics were retrospectively evaluated at baseline and 6 months, 1 and 3 years after the initiation of treatment. d3-GHR was analyzed in 35 patients.

RESULTS

37.1% of patients were d3-GHR carriers (31.4% heterozygous, 5.7% homozygous). IGF-I at baseline was low in 64% of patients and was not related to d3-GHR status. There was no association between the d3-GHR allele and baseline IGF-I (p = 0.14). Although adverse events were more frequent in the d3-GHR carriers (30.7 vs. 18.2% in fl/fl) and in patients with normal IGF-I levels at diagnosis (43.7 vs. 17.8% in patients with low IGF-I levels), this association was not statistically significant. d3-GHR status was not related to the incidence of adverse events (p = 0.4) or treatment discontinuation (p = 0.47). Baseline IGF-I levels were neither associated with adverse events (p = 0.08) nor treatment discontinuation (p = 0.75).

CONCLUSIONS

The d3-GHR allele was not related to baseline levels of IGF-I. Neither d3-GHR nor baseline IGF-I level was related to adverse events or treatment discontinuation.

Analysis of IGF(CA)19 and IGFBP3-202A/C gene polymorphisms in patients with acromegaly: association with clinical presentation and response to treatments

OBJECTIVE

IGF1 and IGFBP3 gene polymorphisms have been recently described. However, their potential role in the setting of acromegaly and its outcome is unknown. In this study, we analyze these polymorphisms in patients with acromegaly and investigate their association with clinical presentation and response to treatments.

DESIGN

A retrospective observational study was conducted in patients with acromegaly to analyze IGF1 and IGFBP3 gene polymorphisms.

METHODS

A total of 124 patients with acromegaly (57.3% women, mean age 44.9±13.1 years old) were followed up for a period of 11.4±8.0 years in eight tertiary referral hospitals in Spain. Clinical and analytical data were evaluated at baseline and after treatment. IGF1 and IGFBP3 gene polymorphisms were analyzed using PCR and specific primers.

RESULTS

Baseline laboratory test results were GH 19.3 (8.0-39.6) ng/ml, nadir GH 11.8 (4.1-21.5) ng/ml, and index IGF1 2.65±1.25 upper limit of normal. Regarding the IGF1 gene polymorphism, we did not find any association between the number of cyto-adenosine (CA) repeats and patients' baseline characteristics. Nevertheless, a trend for higher nadir GH values was observed in patients with <19 CA repeats. Regarding the IGFBP3 polymorphism, the absence of an A allele at the -202 position was associated with a higher baseline IGF1 and a higher prevalence of cancer and polyps. There were no differences in response to therapies according to the specific genotypes.

CONCLUSIONS

Polymorphisms in the IGF1 and IGFBP3 genes may not be invariably determinant of treatment outcome in acromegalic patients, but they may be associated with higher nadir GH levels or baseline IGF1, and determine a higher rate of colorectal polyps and cancer.

Escape and lipodystrophy in acromegaly during pegvisomant therapy, a retrospective multicentre Spanish study

BACKGROUND

Pegvisomant is an effective treatment for acromegaly.

OBJECTIVE

To investigate escape (loss of biochemical control in patients previously controlled) and lipodystrophy in acromegalic patients treated with pegvisomant and to evaluate possible associations with clinical features.

PATIENTS AND METHODS

Multicentre retrospective study involving 19 Spanish centres.

RESULTS

Ninety-seven patients were included (59% women, mean age at diagnosis 42 ± 13 years, 80% macroadenomas); mean follow-up on pegvisomant was 5 ± 2·5 years, and 89 (92%) achieved normal IGF-1. Escape was reported in 30/89 (34%) of responders, after a mean treatment duration of 25 ± 21 months. The mean initial dose of pegvisomant was 11 ± 5 mg/day, and mean dose at escape was 14 ± 7 mg/day. Most patients (26/30, 87%) achieved control with dose increase (57%), additional medical treatment (3%) or both (27%). Mean new dose that controlled IGF-1 after escape was 20 ± 7 mg/day. Treatments associated were somatostatin analogues (SSA in 47%), cabergoline (CAB in 47%) and both (6%). Lipodystrophy was observed in 15 patients (13 females), mild in six, moderate in six, severe in three and persistent in four. Among patients with lipodystrophy, three escaped and three were nonresponders to pegvisomant. Four patients discontinued the drug, and four had dose reductions because of lipodystrophy. It tended to be more frequent in females (P = 0·06) and in patients treated with triple association SSA+CAB+PEG (P = 0·018). No relationship between escape and clinical variables was found, except prior CAB (P = 0·04) and metformin treatment (0·02) and grade of lipodystrophy (P = 0·02).

CONCLUSIONS

A significant proportion of patients treated with pegvisomant escaped (34%); however, the majority (87%) was easily controlled with either dose increase, further medical treatment or both. Lipodystrophy developed in 15%, mostly females, and influenced the response to treatment.

Somatotropinomas, but not nonfunctioning pituitary adenomas, maintain a functional apoptotic RET/Pit1/ARF/p53 pathway that is blocked by excess GDNF

Acromegaly is caused by somatotroph cell adenomas (somatotropinomas [ACROs]), which secrete GH. Human and rodent somatotroph cells express the RET receptor. In rodents, when normal somatotrophs are deprived of the RET ligand, GDNF (Glial Cell Derived Neurotrophic Factor), RET is processed intracellularly to induce overexpression of Pit1 [Transcription factor (gene : POUF1) essential for transcription of Pituitary hormones GH, PRL and TSHb], which in turn leads to p19Arf/p53-dependent apoptosis. Our purpose was to ascertain whether human ACROs maintain the RET/Pit1/p14ARF/p53/apoptosis pathway, relative to nonfunctioning pituitary adenomas (NFPAs). Apoptosis in the absence and presence of GDNF was studied in primary cultures of 8 ACROs and 3 NFPAs. Parallel protein extracts were analyzed for expression of RET, Pit1, p19Arf, p53, and phospho-Akt. When GDNF deprived, ACRO cells, but not NFPAs, presented marked level of apoptosis that was prevented in the presence of GDNF. Apoptosis was accompanied by RET processing, Pit1 accumulation, and p14ARF and p53 induction. GDNF prevented all these effects via activation of phospho-AKT. Overexpression of human Pit1 (hPit1) directly induced p19Arf/p53 and apoptosis in a pituitary cell line. Using in silico studies, 2 CCAAT/enhancer binding protein alpha (cEBPα) consensus-binding sites were found to be 100% conserved in mouse, rat, and hPit1 promoters. Deletion of 1 cEBPα site prevented the RET-induced increase in hPit1 promoter expression. TaqMan qRT-PCR (real time RT-PCR) for RET, Pit1, Arf, TP53, GDNF, steroidogenic factor 1, and GH was performed in RNA from whole ACRO and NFPA tumors. ACRO but not NFPA adenomas express RET and Pit1. GDNF expression in the tumors was positively correlated with RET and negatively correlated with p53. In conclusion, ACROs maintain an active RET/Pit1/p14Arf/p53/apoptosis pathway that is inhibited by GDNF. Disruption of GDNF's survival function might constitute a new therapeutic route in acromegaly.

Cabergoline treatment in acromegaly: pros

Cabergoline is an ergot-derived dopamine D2 receptor agonist which may be effective for the medical management of acromegaly. Its efficacy in reducing growth hormone and IGF-I levels, as well as its antiproliferative and pro-apoptotic effects on pituitary tumor cells, has been observed in several studies. Cabergoline may be used alone or as an add-on therapy to patients who are partially resistant to somatostatin analogs (SSA), or who do not achieve complete control with maximum doses of pegvisomant (PEG). Additionally, the convenience of its oral administration, allowing better compliance, and its lower economic cost, in comparison with SSA and PEG, favor cabergoline as an attractive option for acromegalic patients, who frequently require long-life medical treatment to achieve disease control. The few adverse events observed with prolonged DA therapy, mainly regarding cardiac valve disease, are not frequent at the doses generally used in acromegaly.

Changes in acromegaly treatment over four decades in Spain: analysis of the Spanish Acromegaly Registry (REA)

Since 1997 there is an online National Registry of acromegalic patients in Spain (REA). We aimed to study changes in acromegaly treatment and outcomes over the last four decades in Spain. In REA clinical and biochemical data are collected at diagnosis and updated every one to 2 years. We analyzed the first treatment received and the different treatments administered according to decade of diagnosis of acromegaly: prior to 1980, 1980-1989, 1990-1999 and 2000-2009. Surgical cure rates according to pretreatment with long-acting somatostatin receptor ligands (SRLs) were also analyzed. 1,658 patients were included of which 698 had accurate follow-up data. Treatment of acromegaly changed over time. Surgery was the main treatment option (83.8 %) and medical treatment was widely used (74.7 %) both maintained over decades, while radiation therapy declined (62.8, 61.6, 42.2 and 11.9 % over decades, p < 0.001). First treatment type also changed: surgery was the first line option up until the last decade in which medical treatment was preferred (p < 0.001). Radiotherapy was barely used as first treatment. Treatment combinations changed over time (p < 0.001). The most common treatment combination (surgery plus medical therapy), was received by 24.4, 16.4, 25.3 and 56.5 % of patients over decades. Medical treatment alone was performed in 7.3, 6, 7.2 and 14.7 % over decades. Type of medical treatment also changed, SRLs becoming the first medical treatment modality in the last decades, whereas dopamine agonist use declined (p < 0.001). Surgical cure rates improved over decades (21, 21, 36 and 38 %, p = 0.002) and were not influenced by SRL pre-surgical use. Acromegaly treatment has changed in Spain in the last four decades. Surgery has been the main treatment option for decades; however, medical therapy has replaced surgery as first line in the last decade and radiotherapy rates have clearly declined. SRLs are the most used medical treatment.

Pegvisomant and cabergoline combination therapy in acromegaly

Combination with cabergoline may offer additional benefits to acromegalic patients on pegvisomant monotherapy. We evaluated the safety and efficacy profile of this combination and investigated the determinants of response. An observational, retrospective, cross-sectional study. Fourteen acromegalic patients (9 females), who were partially resistant to somatostatin analogs and on pegvisomant monotherapy. Cabergoline was added because of the presence of persistent mildly increased IGF-I. The mean follow-up time was 18.3 ± 10.4 months. The efficacy and safety profile was assessed. The influence of clinical and biochemical characteristics on treatment efficacy was studied. IGF-I levels returned to normal in 4 patients (28%) at the end of the study. In addition, some decline in IGF-I levels was observed in a further 5 patients. The % IGF-I decreased from 158 ± 64% to 124 ± 44% (p = 0.001). The average change in IGF-I was -18 ± 27% (range -67 to +24%). Lower baseline IGF-I (p = 0.007), female gender (p = 0.013), lower body weight (p = 0.031), and higher prolactin (PRL) levels (p = 0.007) were associated with a better response to combination therapy. There were no significant severe adverse events. Significant tumour shrinkage was observed in 1 patient. Combination therapy with pegvisomant and cabergoline could provide better control of IGF-I in some patients with acromegaly. Baseline IGF-I levels, female gender, body weight, and PRL levels affect the response to this combination therapy.

Epidemiology, mortality rate and survival in a homogeneous population of hypopituitary patients

INTRODUCTION

Hypopituitarism is associated with higher prevalence of cardiovascular risk factors and premature death. Furthermore, some clinical and therapeutic features of hypopituitarism have been associated with a worse prognosis.

OBJECTIVE

We reviewed, retrospectively, a large series of adult patients with hypopituitarism using stringent epidemiological criteria. Prevalence, association with cardiovascular risk factors, mortality and survival have been analysed.

DESIGN AND METHODS

Two hundred and nine adult hypopituitary patients (56·9% females) from a population of 405 218 inhabitants, followed for 10 years.

RESULTS

Prevalence of hypopituitarism at the end of the study was 37·5 cases/100 000 inhabitants. Incidence of hypopituitarism was 2·07 cases/100 000 inhabitants and year. Thirty-two patients died during the period of the study. Standardized mortality rate (SMR) was 8·05, higher in males (8·92 vs 7·34) and in younger patients (84·93 vs 5·26). Diagnosis of acromegaly (P = 0·033), previous radiotherapy (P = 0·02), higher BMI (P = 0·04), diabetes mellitus (P = 0·03) and cancer (P < 0·0001) were associated with mortality. A lower survival was associated with older age at diagnosis, nontumoural causes, previous radiotherapy, diabetes mellitus with poor metabolic control and malignant disease.

CONCLUSIONS

Prevalence of hypopituitarism was 37·5 cases/100 000 inhabitants, and annual incidence was 2·07 cases/100 000 inhabitants. SMR was 8 times higher in hypopituitarism than in general population and was also higher in males and younger patients. Reduced survival was significantly related to cancer, nontumoural causes of hypopituitarism, older age at diagnosis, previous radiotherapy and diabetes mellitus with poor metabolic control.

Germline mutations of AIP gene in somatotropinomas resistant to somatostatin analogues

OBJECTIVE

Most cases of familial isolated pituitary adenomas with mutated aryl hydrocarbon receptor-interacting protein (AIP:HGNC:358) gene develop somatotropinomas. They are characterised by an aggressive clinical phenotype including early age at diagnosis, large tumours and frequent invasiveness. There is little information on AIP gene mutations' prevalence in isolated somatotropinomas characterised by poor response to somatostatin analogue treatment. The aim of this study was to investigate the prevalence of AIP mutations in non-familial cases of somatotropinomas with poor response to conventional treatment.

DESIGN AND METHODS

Fifty patients with acromegaly (22 males/28 females, age 51±18 years) and 60 controls were included in this study performed at eight University Hospitals in Spain. None had family history of pituitary adenomas or other endocrine tumors. All patients failed to respond to conventional treatment including surgery and somatostatin analogues. Some patients received adjuvant radiotherapy and most cases required pegvisomant (PEG) treatment for normalisation of IGF1. AIP analysis was performed in DNA extracted from peripheral leucocytes, using standardised PCR protocol in which the coding regions of exons 1, 2, 3, 4, 5 and 6 were amplified. Possible deletions/duplications were studied using multiplex ligation-dependent probe amplification.

RESULTS

SEQUENCE CHANGES OF POTENTIAL DIFFERENT SIGNIFICANCE THAT COULD BE CONSIDERED AS MUTATIONS OR VARIATIONS OF UNKNOWN SIGNIFICANCE (VUS) OF THE AIP GENE WERE FOUND IN FOUR PATIENTS (8%). IN TWO CASES, TWO DIFFERENT MUTATIONS PREVIOUSLY DESCRIBED WERE FOUND: p.Arg9Gln and p.Phe269Phe. Two other VUS were also found: c.787+24C>T in intron 5 and c.100-18C>T in intron 1. Age at diagnosis ranged from 21 to 50 years old, and in all patients, the tumor was a macroadenoma depicting IGF1 normalisation under PEG treatment.

CONCLUSIONS

AIP germline mutations show a low, but non-negligible, prevalence in non-familial acromegaly patients with tumors resistant to treatment with somatostatin analogues.

Subclinical hypopituitarism

The presence of subclinical or minor pituitary hormone deficiencies could be recognised in clinical practice and might represent intermediate situations among normal pituitary hormone secretion and clinical hypopituitarism. However, this entity has not been correctly identified and associated clinical impairment and even more, long-term consequences regarding to morbidity and mortality, strongly related to clinical hypopituitarism, has not been correctly settled. Furthermore, best test or methods for diagnosis and the cut off to define these intermediate situates are also unknown. With this purpose, long-term controlled studies are needed to define correctly this entity, the appropriate methods for diagnosis and the potential benefits of substitutive hormone therapy in detected cases. The present review will focus on the available evidence concerning the prevalence, clinical features and diagnosis of subclinical hypopituitarism.

High prevalence of AIP gene mutations following focused screening in young patients with sporadic pituitary macroadenomas

BACKGROUND

Aryl hydrocarbon receptor interacting protein (AIP) mutations (AIPmut) cause aggressive pituitary adenomas in young patients, usually in the setting of familial isolated pituitary adenomas. The prevalence of AIPmut among sporadic pituitary adenoma patients appears to be low; studies have not addressed prevalence in the most clinically relevant population. Hence, we undertook an international, multicenter, prospective genetic, and clinical analysis at 21 tertiary referral endocrine departments.

METHODS

We included 163 sporadic pituitary macroadenoma patients irrespective of clinical phenotype diagnosed at <30 years of age.

RESULTS

Overall, 19/163 (11.7%) patients had germline AIPmut; a further nine patients had sequence changes of uncertain significance or polymorphisms. AIPmut were identified in 8/39 (20.5%) pediatric patients. Ten AIPmut were identified in 11/83 (13.3%) sporadic somatotropinoma patients, in 7/61 (11.5%) prolactinoma patients, and in 1/16 non-functioning pituitary adenoma patients. Large genetic deletions were not seen using multiplex ligation-dependent probe amplification. Familial screening was possible in the relatives of seven patients with AIPmut and carriers were found in six of the seven families. In total, pituitary adenomas were diagnosed in 2/21 AIPmut-screened carriers; both had asymptomatic microadenomas.

CONCLUSION

Germline AIPmut occur in 11.7% of patients <30 years with sporadic pituitary macroadenomas and in 20.5% of pediatric patients. AIPmut mutation testing in this population should be considered in order to optimize clinical genetic investigation and management.

Coadministration of lanreotide Autogel and pegvisomant normalizes IGF1 levels and is well tolerated in patients with acromegaly partially controlled by somatostatin analogs alone

OBJECTIVE

To evaluate the efficacy and safety of coadministered lanreotide Autogel (LA; 120  mg/month) and pegvisomant (40-120  mg/week) in acromegaly.

DESIGN

This is a 28-week, multicenter, open-label, single-arm sequential study.

METHODS

Patients (n=92) biochemically uncontrolled, on somatostatin analogs (SSAs) or using pegvisomant monotherapy entered a 4-month run-in taking LA (120  mg/month). Patients uncontrolled after the run-in period (n=57) entered a 28-week coadministration period, receiving LA 120  mg/month plus pegvisomant (60  mg once weekly, adapted every 8 weeks based on IGF1 levels to 40-80  mg once weekly or 40 or 60  mg twice weekly).

RESULTS

In total, 33 (57.9%) patients had normalized IGF1 following coadministration (P<0.0001 versus 30% minimum clinically relevant); median pegvisomant dose in normalized patients was 60  mg/week. IGF1 normalized at any time during coadministration in 45 (78.9%) patients (P<0.0001) with median pegvisomant dose at 60  mg/week. Being nondiabetic (odds ratio (OR): 4.65) and older (OR, upper versus lower quartile: 3.40) showed increased likelihood of normalization. Symptom reduction was greatest for arthralgia (-0.6 ± 1.6) and soft tissue swelling (-0.6 ± 1.8). Five patients reported treatment-emergent adverse events causing treatment withdrawal: three serious (treatment related - thrombocytopenia, urticaria; not treatment related - abdominal pain/vomiting) and two nonserious (hepatotoxicity and cytolytic hepatitis, both elevating alanine aminotransferase to >5 × upper limit of normal with normalization after withdrawal).

CONCLUSIONS

In patients partially controlled by SSAs, LA (120  mg/month) plus pegvisomant normalized IGF1 in 57.9% of patients after 7 months, at a median effective pegvisomant dose of 60  mg/week, and 78.9% at any time. In these patients, results suggest a pegvisomant-sparing effect versus daily pegvisomant monotherapy.

Somatotroph tumor progression during pegvisomant therapy: a clinical and molecular study

CONTEXT

There is concern that pegvisomant could be associated with a higher risk of tumor growth. The rate and possible determinants of this tumor growth are unknown.

OBJECTIVE

The objective of the study was to investigate the clinical, immunohistological, and molecular factors conditioning tumor growth in patients taking pegvisomant.

DESIGN AND SETTING

This was a cross-sectional study performed from 2004 to 2010 in four university hospitals in Spain.

PATIENTS

Seventy-five acromegalic patients with active disease resistant to somatostatin analogs treated with pegvisomant were followed up for a mean of 29 ± 20 months.

MAIN OUTCOME MEASURES

Magnetic resonance images before initiation of pegvisomant, at 6 months, and then yearly were examined in all patients. Immunohistological and molecular studies were performed in tumors that grew.

RESULTS

A significant increase in tumor size was observed in five patients (6.7%). Absence of previous irradiation (P = 0.014) and shorter duration of prepegvisomant somatostatin analog therapy (P < 0.001) were associated with an increased risk of tumor growth. A stepwise multivariate linear regression analysis (R(2) = 0.334, P < 0.001) identified the duration of somatostatin analog therapy prior to pegvisomant (beta = -4.509, P = 0.014) as the only significant predictor of tumor growth. In those tumors that grew, GH expression and insulin receptor expression were higher (P = 0.033 in both cases) than in the control group.

CONCLUSIONS

No previous radiotherapy, shorter duration of prepegvisomant somatostatin analog therapy, and higher tumor expression of GH and insulin receptor could be risk factors for tumor growth during pegvisomant therapy.

Pituitary stalk dysgenesis-induced hypopituitarism in adult patients: prevalence, evolution of hormone dysfunction and genetic analysis

OBJECTIVES

To investigate the prevalence of pituitary stalk dysgenesis (PSD) in adult hypopituitary patients by describing the chronology of hormone deficiencies and their potential correlation with traumatic delivery, mutations in genes required for pituitary development and function and pituitary stalk visibility on MRI.

DESIGN

Retrospective and prospective study involving 231 hypopituitary patients, including 26 diagnosed with PSD. Clinical, biochemical and radiological studies were reviewed. Molecular analyses of HESX1, LHX4,PROP1 and POU1F1 genes were performed prospectively.

RESULTS

PSD was present in 11.2% of hypopituitary patients. PSD was diagnosed before 14 years of age in 46.2% of cases, between 14 and 18 years of age in 23%, and in adulthood in 30.8%. Perinatal complications or gene mutations were present in 26.9 and 4.3% of patients, respectively. At first assessment, 92.3% of patients had growth hormone (GH) deficiency. 26.9% presented as combined pituitary deficiencies and 7.6% as panhypopituitarism. Hormone deficiencies were progressive during follow-up in 84.6%. 96% progressed to multiple deficiencies and 46% to panhypopituitarism. No significant association was found between hormonal dysfunction and previous perinatal damage or breech delivery (p = 0.17), PROP1 mutations (p = 0.26) or pituitary stalk visibility on MRI (p = 0.52). No mutations in POU1F1, HESX1 and LHX-4 genes were detected.

CONCLUSION

In this study, PSD prevalence in adult hypopituitary patients was 11.2%. Typical clinical presentation includes isolated or combined pituitary hormone deficiencies during the pediatric age, which usually progress to combined or complete hypopituitarism in adulthood. Phenotype is highly variable depending on hormone profile and age at onset.

Hypopituitarism following traumatic brain injury: determining factors for diagnosis

Neuroendocrine dysfunction, long recognized as a consequence of traumatic brain injury (TBI), is a major cause of disability that includes physical and psychological involvement with long-term cognitive, behavioral, and social changes. There is no standard procedure regarding at what time after trauma the diagnosis should be made. Also there is uncertainty on defining the best methods for diagnosis and testing and what types of patients should be selected for screening. Common criteria for evaluating these patients are required on account of the high prevalence of TBI worldwide and the potential new cases of hypopituitarism. The aim of this review is to clarify, based on the evidence, when endocrine assessment should be performed after TBI and which patients should be evaluated. Additional studies are still needed to know the impact of post-traumatic hypopituitarism and to assess the impact of hormone replacement in the prognosis.

Pegvisomant-induced liver injury is related to the UGT1A1*28 polymorphism of Gilbert's syndrome

CONTEXT

Pegvisomant (PEG) therapy has been associated with drug-induced liver dysfunction in acromegalic patients. The mechanism of its toxicity remains unknown.

OBJECTIVE

The primary objective was to determine whether or not the UGT1A1*28 polymorphism associated with Gilbert's syndrome influences the development of liver dysfunction during PEG treatment.

DESIGN AND SETTING

A cross-sectional study was conducted in four Spanish university hospitals.

PATIENTS

Thirty-six acromegalic patients with active disease, resistant to somatostatin analogs, participated.

RESULTS

The prevalence of the UGT1A1*28 homozygous and heterozygous genotypes in acromegalic patients was 14 and 44%, respectively. Ten patients (28%) developed liver function test (LFT) abnormalities. There was a tendency for more frequent liver function abnormalities in males (70% males vs. 30% females, P = 0.058). Carriers of the UGT1A1*28 polymorphism had a higher incidence of LFT abnormalities than the UGT1A1 wild type (43% carriers vs. 7% wild type, P = 0.024). This difference persisted when adjusted in an all-factors multiple regression analysis [coefficient of determination (R(2)) = 0.463; P = 0.008] for age, gender, alcohol consumption, and UGT1A1*28 polymorphism. A stepwise multivariate likelihood binary logistic regression analysis (R(2) = 0.40; P = 0.003) identified male gender (beta = 7.21; P = 0.033) and UGT1A1*28 polymorphism (beta = 14.1; P = 0.028) as the only significant predictors for the development of LFT abnormalities.

CONCLUSIONS

The UGT1A1*28 genotype and male gender predict an increased incidence of LFT abnormalities during PEG therapy in acromegaly.

The exon 3-deleted growth hormone receptor is associated with better response to pegvisomant therapy in acromegaly

CONTEXT

The deletion of exon 3 in the GH receptor (GHR) has been associated with a different biochemical picture and response to therapy in acromegaly.

OBJECTIVE

The aim of the study was to determine whether or not the GHR genotype influences the efficacy of pegvisomant treatment.

DESIGN AND SETTING

A cross-sectional study was conducted in six Spanish university hospitals.

PATIENTS

Forty-four acromegalic patients with active disease and resistance to somatostatin analogs participated in the study.

RESULTS

The prevalence of the full-length GHR and the exon 3-deleted GHR homozygous and heterozygous genotypes was 41, 2, and 57%, respectively. There were no differences in IGF-I or GH pre-pegvisomant levels related to GHR genotype. The exon 3-deleted patients required approximately 20% lower doses of pegvisomant per kilogram of weight (28 +/- 11 compared to 22 +/- 7 mg per kg of weight; P = 0.033) to normalize IGF-I. A stepwise multivariate linear regression analysis (R(2) = 0.27; P = 0.003) identified male gender (beta = -0.79; P = 0.03) and d3-GHR genotype (beta = -0.64; P = 0.007) as the only significant predictors of the dose of pegvisomant per kilogram of weight. In addition, d3-GHR carriers required fewer months for IGF-I normalization (P < 0.01). A stepwise multivariate linear regression analysis (R(2) = 0.40; P = 0.001) revealed that the only significant predictor of the time to IGF-I normalization was the dose of pegvisomant per kilogram of weight (beta = 0.451; P = 0.001).

CONCLUSIONS

The exon 3 deletion in the GHR predicts an improved response to pegvisomant therapy in acromegaly.

Thyroid-type solid cell nests in struma ovarii

Solid cell nests (SCNs) of the thyroid are single or multiple foci of solid and/or cystic clusters of squamoid cells (main cells) with a minor proportion of C-cells, found in the normal thyroid. The SCNs have also been reported in the heart as an ultimobranchial heterotopia. Here, the authors describe a case of thyroid-type SCNs associated with struma ovarii. Main cells were positive for simple and stratified epithelial-type cytokeratins, carcinoembryonic antigen, carbohydrate antigen 19.9, p63, bcl-2, and galectin-3. The neuroendocrine cell population was positive for chromogranin A and synaptophysin but negative for calcitonin, suggesting a common ancestor cell capable of dual differentiation toward thyroid follicular cells and hindgut-type endocrine cells. The existence of thyroid-type SCNs in struma ovarii could be easily understood by considering the struma ovarii as a teratoma; at the same time, these findings also support the idea of a close histogenetic link between the main cells of SCNs and thyroid tissue.

Pegvisomant-induced cholestatic hepatitis with jaundice in a patient with Gilbert's syndrome

We report on a patient with active acromegaly and Gilbert's syndrome who developed severe hepatic dysfunction during pegvisomant (PEGv) monotherapy. She was partially resistant to all previous therapies, including long-acting somatostatin analogs and cabergoline. Five months after starting PEGv therapy, with an already normalized IGF1, she developed cholestatic liver dysfunction with jaundice. Liver or biliary diseases including biliary sludge, cholelithiasis or liver steatosis were excluded. A liver biopsy was in keeping with drug-induced liver injury. The discontinuation of PEGv was followed by full clinical and biochemical recovery in 6 weeks. PEGv therapy was not resumed. Apart from a minimal increase of bilirubin levels, no liver function test abnormalities were found during the 4-year follow-up period after the PEGv was discontinued. Drug-induced liver injury is the most serious systemic adverse event resulting from PEGv therapy. Since patients with mild and asymptomatic liver disease could be at a higher risk of PEGv-induced hepatotoxicity, frequent monitoring of hepatic enzymes should be required in these cases.

Long-term treatment of acromegalic patients resistant to somatostatin analogues with the GH receptor antagonist pegvisomant: its efficacy in relation to gender and previous radiotherapy

CONTEXT

Pegvisomant is an effective treatment for somatostatin analogue-resistant acromegaly, but the determinants defining the response to this treatment are largely unknown.

OBJECTIVE

To investigate the efficacy of pegvisomant treatment in resistant acromegalic patients (e.g. serum IGF1 at least 1.25 x upper normal limit) in a clinical setting and the factors conditioning this response.

DESIGN AND SETTING

A retrospective cross-sectional study performed in six Spanish University hospitals from 2004 to 2007. Patients Forty-four acromegalic patients (61.4% female, mean age: 49+/-14), 95% of whom had undergone pituitary surgery and 61% having received pituitary radiotherapy. The mean follow-up was 22.7+/-11.2 months. Main outcome measures IGF1 levels reflected treatment efficacy, and the influence of gender, age, weight, previous radiotherapy and duration of treatment was assessed.

RESULTS

IGF1 normalisation was achieved in 84% of the patients. Male gender (P<0.05), previous irradiation (P<0.05) and the treatment duration (r=0.364, P<0.02) were associated with a better response to pegvisomant therapy. There was a significant decrease in HbA1c (P<0.001) and in the mean insulin dose (P<0.01) in acromegalic diabetic patients. Although 25% of patients experienced mild adverse events, pegvisomant was only withdrawn in four patients due to side effects (two cases of tumour growth, one liver dysfunction and one headache).

CONCLUSIONS

Long-term pegvisomant is a very effective therapy in resistant acromegaly. Male gender and prior radiotherapy influence the therapeutic response rate.

Anterior pituitary function in Cushing's syndrome: study of 36 patients

We studied the anterior pituitary function in 36 patients (25 females and 11 males, mean age: 35 years) with untreated Cushing's syndrome by simultaneous triple stimulus with insulin, TRH and LHRH. Thirty-one patients (86%) had Cushing's disease and five (14%) had an adrenal adenoma. We observed a lack of response of GH to hypoglycemia in 88%, TSH to TRH in 91%, LH to LHRH in 30%, FSH to LHRH in 12% and PRL to TRH in 6% of the patients. Low-to-normal total thyroxine (T4) values were obtained in 37%, with low triiodothyronine levels in 87%. The free-T4 index was normal in all patients. Total testosterone was low in only one adult man, while estradiol and progesterone were low in 45% and 15% of premenopausal women, respectively. We observed no differences in either axis among patients with Cushing's syndrome of different etiologies. Nor was there any statistical difference between the frequency of alteration of each axis and the levels of urinary free cortisol or the duration of the disease. We conclude that hypercortisolism is responsible for the abnormalities in anterior pituitary function in Cushing's syndrome.

[Thyrotropin-producing adenoma of the hypophysis]

A patient with a thyrotropin (TSH) secreting pituitary adenoma had hyperthyroidism with high levels of thyroid hormones and inadequate TSH secretion. After the challenge with thyrotropin releasing hormone (TRH), TSH level did not change. The normalization of plasma levels of thyroid hormones with antithyroid drugs was followed by an important increase in TSH levels. The adenoma was resected by the transphenoidal route and the diagnosis was confirmed by immunohistochemical study. Inadequate TSH secretion persisted after surgery, and radiation therapy with lineal accelerator was attempted. At present, one year after radiation therapy, inadequate TSH secretion requiring antithyroid drugs persists. We describe this clinical picture and briefly discuss the literature.