Mirtha Guitelman

Clinical characteristics and therapeutic responses in patients with Germ-line AIP mutations and pituitary adenomas : An international collaborative study

CONTEXT AIP mutations (AIPmut) give rise to a pituitary adenoma predisposition that occurs in familial isolated pituitary adenomas and less often in sporadic cases. The clinical and therapeutic features of AIPmut-associated pituitary adenomas have not been studied comprehensively. OBJECTIVE The objective of the study was to assess clinical/therapeutic characteristics of AIPmut pituitary adenomas. DESIGN This study was an international, multicenter, retrospective case collection/database analysis. SETTING The study was conducted at 36 tertiary referral endocrine and clinical genetics departments. PATIENTS Patients included 96 patients with germline AIPmut and pituitary adenomas and 232 matched AIPmut-negative acromegaly controls. RESULTS The AIPmut population was predominantly young and male (63.5%); first symptoms occurred as children/adolescents in 50%. At diagnosis, most tumors were macroadenomas (93.3%); extension and invasion was common. Somatotropinomas comprised 78.1% of the cohort; there were also prolactinomas (n = 13), nonsecreting adenomas (n = 7), and a TSH-secreting adenoma. AIPmut somatotropinomas were larger (P = 0.00026), with higher GH levels (P = 0.00068), more frequent extension (P = 0.018) and prolactin cosecretion (P = 0.00023), and occurred 2 decades before controls (P < 0.000001). Gigantism was more common in the AIPmut group (P < 0.000001). AIPmut somatotropinoma patients underwent more surgical interventions (P = 0.00069) and had lower decreases in GH (P = 0.00037) and IGF-I (P = 0.028) and less tumor shrinkage with somatostatin analogs (P < 0.00001) vs. controls. AIPmut prolactinomas occurred generally in young males and frequently required surgery or radiotherapy. CONCLUSIONS AIPmut pituitary adenomas have clinical features that may negatively impact treatment efficacy. Predisposition for aggressive disease in young patients, often in a familial setting, suggests that earlier diagnosis of AIPmut pituitary adenomas may have clinical utility.

Pasireotide versus continued treatment with octreotide or lanreotide in patients with inadequately controlled acromegaly (PAOLA): a randomised, phase 3 trial

BACKGROUND Many patients with acromegaly do not achieve biochemical control despite receiving high doses of the first-generation somatostatin analogues octreotide or lanreotide. In the PAOLA trial, we aimed to assess the efficacy and safety of two different doses of the somatostatin analogue pasireotide long-acting release compared with active control (octreotide or lanreotide) in patients with inadequately controlled acromegaly. METHODS In a multicentre, randomised, phase 3 trial, we enrolled eligible patients aged 18 years or older with acromegaly who were inadequately controlled (5-point, 2 h mean growth hormone concentration >2·5 μg/L and insulin-like growth factor 1 [IGF-1] concentration >1·3 times the upper normal limit) and had received 30 mg octreotide long-acting repeatable or 120 mg lanreotide (Somatuline Autogel; Ipsen, UK) as monotherapy for 6 months or longer. We randomly assigned patients in a 1:1:1 ratio with an interactive voice-web response system to receive 40 mg pasireotide long-acting release once every 28 days for 24 weeks, 60 mg pasireotide long-acting release once every 28 days for 24 weeks, or continued treatment with octreotide or lanreotide (active control). Patients were stratified according to previous treatment (octreotide or lanreotide) and growth hormone concentrations at screening (2·5-10 μg/L and >10 μg/L). Patients and study investigators were not masked to study drug assignment but were masked to pasireotide dose allocation. The primary endpoint was number of patients achieving biochemical control, defined as mean growth hormone concentration less than 2·5 μg/L and normalised IGF-1 concentration. Efficacy analyses were based on intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01137682. FINDINGS Between Dec 17, 2010, and Aug 6, 2012, 198 patients were enrolled and randomly assigned to pasireotide 40 mg (n=65), pasireotide 60 mg (n=65), or active control (n=68) groups. At 24 weeks, ten (15%) patients in the pasireotide 40 mg group and 13 (20%) patients in the pasireotide 60 mg group achieved biochemical control, compared with no patients in the active control group (absolute difference from control group 15·4%, 95% CI 7·6-26·5, p=0·0006 for pasireotide 40 mg group, 20·0%, 11·1-31·8, p<0·0001 for pasireotide 60 mg group). The most common adverse events were hyperglycaemia (21 [33%] for treatment with 40 mg pasireotide, 19 [31%] with 60 mg pasireotide, and nine [14%] with active control), diabetes (13 [21%], 16 [26%], and five [8%]), and diarrhoea (ten [16%], 12 [19%], and three [5%]); most were grade 1 or 2 in severity. Serious adverse events were reported in six (10%) patients in the pasireotide 40 mg group, two (3%) in the pasireotide 60 mg group, and three (5%) in the active control group. INTERPRETATION Pasireotide provides superior efficacy compared with continued treatment with octreotide or lanreotide, and could become the new standard pituitary-directed treatment in patients with acromegaly who are inadequately controlled using first-generation somatostatin analogues. FUNDING Novartis Pharma AG. Financial support for medical editorial assistance was provided by Novartis Pharmaceuticals Corporation.

Cyclin-dependent kinase inhibitor 1B(CDKN1B) gene variants in AIP mutation-negative familial isolated pituitary adenoma kindreds

Familial isolated pituitary adenoma (FIPA) occurs in families and is unrelated to multiple endocrine neoplasia type 1 and Carney complex. Mutations in AIP account only for 15-25% of FIPA families. CDKN1B mutations cause MEN4 in which affected patients can suffer from pituitary adenomas. With this study, we wanted to assess whether mutations in CDKN1B occur among a large cohort of AIP mutation-negative FIPA kindreds. Eighty-eight AIP mutation-negative FIPA families were studied and 124 affected subjects underwent sequencing of CDKN1B. Functional analysis of putative CDKN1B mutations was performed using in silico and in vitro approaches. Germline CDKN1B analysis revealed two nucleotide changes: c.286A>C (p.K96Q) and c.356T>C (p.I119T). In vitro, the K96Q change decreased p27 affinity for Grb2 but did not segregate with pituitary adenoma in the FIPA kindred. The I119T substitution occurred in a female patient with acromegaly. p27(I119T) shows an abnormal migration pattern by SDS-PAGE. Three variants (p.S56T, p.T142T, and c.605+36C>T) are likely nonpathogenic because In vitro effects were not seen. In conclusion, two patients had germline sequence changes in CDKN1B, which led to functional alterations in the encoded p27 proteins in vitro. Such rare CDKN1B variants may contribute to the development of pituitary adenomas, but their low incidence and lack of clear segregation with affected patients make CDKN1B sequencing unlikely to be of use in routine genetic investigation of FIPA kindreds. However, further characterization of the role of CDKN1B in pituitary tumorigenesis in these and other cases could help clarify the clinicopathological profile of MEN4.

Experience from the Argentine Pegvisomant Observational Study: Preliminary Data

The GH receptor antagonist pegvisomant is an efficient agent to achieve biochemical control of acromegaly in those cases refractory to surgery and medical therapy with somatostatin analogs. We conducted an observational multicenter study consisting of data collection in accordance with the standard management of patients with acromegaly in everyday practice. We reviewed the medical records of 28 patients, 23 females, who were treated with pegvisomant due to the lack of biochemical response or intolerance to the somatostatin analogs. The objective was to monitor long-term safety and efficacy of the antagonist. 82% of the patients had previous pituitary surgery, 53.6% radiotherapy and 96.4% received medical therapy for acromegaly. Only 19.2% of the patients had pituitary residual tumor size larger than 1 cm, the remainder harbored a microadenoma or no visible tumor in the pituitary images. In terms of biochemical efficacy, IGF-I levels decreased to normal ranges in 45% and 58.8% of patients after 3 and 6 months of treatment, respectively, the daily mean dose of pegvisomant being 9.6+/-1.1 mg. Adverse events, potentially related to pegvisomant were reported in 6 patients (21.4%), local injection site reaction and elevated liver enzymes being the most frequent. Tumor size did not show enlargement in the evaluated population (15 patients) during the period of the study. This paper presents preliminary data from a small observational study in Argentina which represents the first database in our country.

Patient-focussed outcomes in acromegaly

BackgroundHealth-related quality of life (QoL) is severely impaired in acromegaly due to the physical and psychological consequences of the disease. Pharmacological and surgical treatments, when available, can improve QoL and life expectancy.Case descriptionA 34-year-old male with uncontrolled acromegaly due to a large and invasive macroadenoma, which could not be resected by transsphenoidal surgery. Over 9 years, he had limited access to pharmacological interventions and persisted with clinically and biochemically active disease, with severe co-morbidities and a poor QoL, which eventually lead to a premature sudden death.ConclusionThis case highlights the impact that active acromegaly has when treatment resources are limited. We review the factors contributing to poor QoL in this disease, with special reference to the Latin American scenario.

Pheochromocytomas and pituitary adenomas in three patients with MAX exon deletions

Copy number variations (CNV), an important genetic mechanism in inherited tumor genetics, can affect large genetic regions or can be limited to smaller regions within genes, such deletions of single exons. Such exon deletions can be challenging to identify and sequencing can be normal in these cases. Multiplex ligation dependent probe amplification (MLPA) can identify CNV of individual exons. Mutations in the MAX gene are associated with a risk of sporadic and hereditary pheochromocytoma. As mutations in other pheochromocytoma related genes can also cause pituitary tumors (3P-Association), we studied whether MAX exon deletions were involved in the etiology of patients with an unexplained association of multiple endocrine neoplasia including pituitary adenoma and pheochromocytoma. Using MLPA we identified three patients with pheochromocytoma and pituitary adenomas who had normal MAX sequencing but presented germline heterozygous MAX exon deletions. The three patients had either acromegaly (n=2) or prolactinoma (n=1) in association with bilateral or recurrent pheochromocytoma. Two had germline heterozygous deletions of single exons of MAX, the other had a germline heterozygous deletion of MAX exons 1-3. MAX immunohistochemical staining was lost in the pheochromocytomas of all three patients and genetic analysis confirmed loss of heterozygosity in tumor DNA. A MAX exon deletion was also transmitted from one patient to a currently asymptomatic offspring. Screening studies of pheochromocytoma patients should take into account the potential for co-existing pituitary tumors. MLPA or other techniques to identify discrete MAX exon deletions should be considered in individuals with pheochromocytoma that are negative following comprehensive sequencing.

Long-Term Follow-Up of Prolactinomas: Should Dopamine Agonist Treatment Be Life-Long?

Dopamine agonists (DA) are the treatment of choice for both micro- and macroadenomas. However, the only limitation of this treatment is the low rate of cure, as well as the long-term therapy usually seen in most patients. In our data, 16% of patients with prolactinomas remained normoprolactinemic after DA withdrawal. The duration of treatment before DA discontinuation was the only statistically significant factor in the cured versus the remission groups. Taking into account all the data from the published series, the rate of cure after DA withdrawal ranged from 5 to 37.5%, and only 1% of tumor regrowth was observed in spite of the high recurrence rate. The board of experts provided recommendations based on the revision of all the data presented at this consensus meeting: dopamine agonists can be routinely withdrawn in patients receiving DA. The length of treatment recommended is 1-3 years, during which DA may be tapered off, and serum PRL levels should be monitored. Tumor disappearance on MRI and the levels of PRL under the lower dose of DA will be determinant for DA withdrawal. Factors influencing prolactinomas outcome are analyzed in the discussion.

Prolactinomas: evolution after menopause

OBJETIVE The aim was to assess the evolution of tumor size and prolactin (PRL) levels in patients with micro and macroprolactinomas diagnosed and treated with dopamine agonists during fertile age, and the effects of suspension of drugs after menopause. SUBJECTS AND METHODS Retrospective study, 29 patients with prolactinomas, 22 microadenomas and 7 macroadenomas, diagnosed during their fertile age were studied in their menopause; treatment was stopped in this period. Age at menopause was 49 ± 3.6 years. The average time of treatment was 135 ± 79 months. The time of follow-up after treatment suspension was 4 to 192 months. Results: Pre-treatment PRL levels in micro and macroadenomas were 119 ± 57 ng/mL and 258 ± 225 ng/mL, respectively. During menopause after treatment suspension, and at the latest follow-up: in microadenomas PRL levels were 23 ± 13 ng/mL and 16 ± 5.7 ng/mL, respectively; in macroadenomas, PRL levels were 20 ± 6.6 ng/mL 5t5and 25 ± 18 ng/mL, respectively. In menopause after treatment suspension, the microadenomas had disappeared in 9/22 and had decreased in 13/22. In the group of patients whose tumor had decreased, in the latest follow-up, tumors disappeared in 7/13 and remained unchanged in 6/13. In macroadenomas, after treatment suspension 3/7 had disappeared, 3/7 decreased and 1/7 remained unchanged. In the latest control in the 3 patients whose tumor decreased, disappeared in 1/3, decreased in 1/3 and there was no change in the remaining. CONCLUSIONS Normal PRL levels and sustained reduction or disappearance of adenomas were achieved in most of patients, probably due to the decrease of estrogen levels. Dopamine agonists might be stopped after menopause in patients with prolactinomas.

Serum Insulin-Like Growth Factor-1 Measurement in the Diagnosis and Follow-up of Patients with Acromegaly: Preliminary Data

Measurement of serum insulin-like growth factor-1 (IGF-I) is the current method for diagnosing and monitoring acromegaly. However, the use of commercially available kits needs to be validated. In our study, we have investigated the use of two different IGF-I immunoassays in patients already diagnosed with acromegaly. We compared a two-site immunoradiometric assay with ethanol-acid extraction (IRMA-DSL) and a solid-phase chemiluminescent immunometric assay (ICMA-IMMULITE), correlating the clinical finding with the biochemical results. A total of 102 samples (77 women and 25 men aged 18-79 years) were analyzed with the two different IGF-I assays. Sixty-four of samples had been taken from patients with acromegaly in different stages. Pearson regression showed a high correlation coefficient; otherwise, Bland and Altman analyses showed a mean difference of 177.6 ng/ml, with upper and lower limits of -183.5 and 538.7 ng/ml in the 102 samples studied. Normal serum IGF-I was found in 64 and 41.5% of patients with treated acromegaly when measured by ICMA and IRMA, respectively. In our study, IGF-I-ICMA had a better clinical correlation in patients with treated acromegaly. The reevaluation of current IGF-I immunoassays is necessary to correctly interpret treatment response in acromegalic patients and thus achieve a better correlation between clinical and biochemical results.

New Insights in Cushing Disease Treatment With Focus on a Derivative of Vitamin A

Cushing’s disease (CD) is an endocrine disorder originated by a corticotroph tumor. It is linked with high mortality and morbidity due to chronic hypercortisolism. Treatment goals are to control cortisol excess and achieve long-term remission, therefore, reducing both complications and patient’s mortality. First-line of treatment for CD is pituitary’s surgery. However, 30% of patients who undergo surgery experience recurrence in long-term follow-up. Persistent or recurrent CD demands second-line treatments, such as pituitary radiotherapy, adrenal surgery, and/or pharmacological therapy. The latter plays a key role in cortisol excess control. Its targets are inhibition of adrenocorticotropic hormone (ACTH) production, inhibition of adrenal steroidogenesis, or antagonism of cortisol action at its peripheral receptor. Retinoic acid (RA) is a metabolic product of vitamin A (retinol) and has been studied for its antiproliferative effects on corticotroph tumor cells. It has been shown that this drug regulates the expression of pro-opiomelanocortin (POMC), ACTH secretion, and tumor growth in corticotroph tumor mouse cell lines and in the nude mice experimental model, via inhibition of POMC transcription. It has been shown to result in tumor reduction, normalization of cortisol levels and clinical improvement in dogs treated with RA for 6 months. The orphan nuclear receptor COUP-TFI is expressed in normal corticotroph cells, but not in corticotroph tumoral cells, and inhibits RA pathways. A first clinical human study demonstrated clinical and biochemical effectiveness in 5/7 patients treated with RA for a period of up to 12 months. In a recent second clinical trial, 25% of 16 patients achieved eucortisolemia, and all achieved a cortisol reduction after 6- to 12-month treatment. The goal of this review is to discuss in the context of the available and future pharmacological treatments of CD, RA mechanisms of action on corticotroph tumor cells, and future perspectives, focusing on potential clinical implementation.