P.-F. Plouin

An Expert Consensus Statement on Use of Adrenal Vein Sampling for the Subtyping of Primary Aldosteronism

Adrenal venous sampling is recommended by current guidelines to identify surgically curable causes of hyperaldosteronism but remains markedly underused. Key factors contributing to the poor use of adrenal venous sampling include the prevailing perceptions that it is a technically challenging procedure, difficult to interpret, and can be complicated by adrenal vein rupture. In addition, the lack of uniformly accepted standards for the performance of adrenal venous sampling contributes to its limited use. Hence, an international panel of experts working at major referral centers was assembled to provide updated advice on how to perform and interpret adrenal venous sampling. To this end, they were asked to use the PICO (Patient or Problem, Intervention, Control or comparison, Outcome) strategy to gather relevant information from the literature and to rely on their own experience. The level of evidence/recommendation was provided according to American Heart Association gradings whenever possible. A consensus was reached on several key issues, including the selection and preparation of the patients for adrenal venous sampling, the procedure for its optimal performance, and the interpretation of its results for diagnostic purposes even in the most challenging cases.

MAX mutations cause hereditary and sporadic pheochromocytoma and paraganglioma.

Purpose: Pheochromocytomas (PCC) and paragangliomas (PGL) are genetically heterogeneous neural crest–derived neoplasms. Recently we identified germline mutations in a new tumor suppressor susceptibility gene, MAX (MYC-associated factor X), which predisposes carriers to PCC. How MAX mutations contribute to PCC/PGL and associated phenotypes remain unclear. This study aimed to examine the prevalence and associated phenotypic features of germline and somatic MAX mutations in PCC/PGL. Design: We sequenced MAX in 1,694 patients with PCC or PGL (without mutations in other major susceptibility genes) from 17 independent referral centers. We screened for large deletions/duplications in 1,535 patients using a multiplex PCR-based method. Somatic mutations were searched for in tumors from an additional 245 patients. The frequency and type of MAX mutation was assessed overall and by clinical characteristics. Results: Sixteen MAX pathogenic mutations were identified in 23 index patients. All had adrenal tumors, including 13 bilateral or multiple PCCs within the same gland (P < 0.001), 15.8% developed additional tumors at thoracoabdominal sites, and 37% had familial antecedents. Age at diagnosis was lower (P = 0.001) in MAX mutation carriers compared with nonmutated cases. Two patients (10.5%) developed metastatic disease. A mutation affecting MAX was found in five tumors, four of them confirmed as somatic (1.65%). MAX tumors were characterized by substantial increases in normetanephrine, associated with normal or minor increases in metanephrine. Conclusions: Germline mutations in MAX are responsible for 1.12% of PCC/PGL in patients without evidence of other known mutations and should be considered in the genetic work-up of these patients. Clin Cancer Res; 18(10); 2828–37. ©2012 AACR.

The Adrenal Vein Sampling International Study (AVIS) for Identifying the Major Subtypes of Primary Aldosteronism

CONTEXTnIn patients who seek surgical cure of primary aldosteronism (PA), The Endocrine Society Guidelines recommend the use of adrenal vein sampling (AVS), which is invasive, technically challenging, difficult to interpret, and commonly held to be risky.nnnOBJECTIVEnThe aim of this study was to determine the complication rate of AVS and the ways in which it is performed and interpreted at major referral centers.nnnDESIGN AND SETTINGSnThe Adrenal Vein Sampling International Study is an observational, retrospective, multicenter study conducted at major referral centers for endocrine hypertension worldwide.nnnPARTICIPANTSnEligible centers were identified from those that had published on PA and/or AVS in the last decade.nnnMAIN OUTCOME MEASUREnThe protocols, interpretation, and costs of AVS were measured, as well as the rate of adrenal vein rupture and the rate of use of AVS.nnnRESULTSnTwenty of 24 eligible centers from Asia, Australia, North America, and Europe participated and provided information on 2604 AVS studies over a 6-yr period. The percentage of PA patients systematically submitted to AVS was 77% (median; 19-100%, range). Thirteen of the 20 centers used sequential catheterization, and seven used bilaterally simultaneous catheterization; cosyntropin stimulation was used in 11 centers. The overall rate of adrenal vein rupture was 0.61%. It correlated directly with the number of AVS performed at a particular center (P = 0.002) and inversely with the number of AVS performed by each radiologist (P = 0.007).nnnCONCLUSIONSnDespite carrying a minimal risk of adrenal vein rupture and at variance with the guidelines, AVS is not used systematically at major referral centers worldwide. These findings represent an argument for defining guidelines for this clinically important but technically demanding procedure.

Head and Neck Paragangliomas in Von Hippel-Lindau Disease and Multiple Endocrine Neoplasia Type 2

BACKGROUNDnHead and neck paragangliomas (HNPs) occur as sporadic or familial entities, the latter mostly in association with germline mutations of the SDHB, SDHC, or SDHD (SDHx) genes. Heritable non-SDHx HNP might occur in von Hippel-Lindau disease (VHL, VHL gene), multiple endocrine neoplasia type 2 (MEN2, RET gene), and neurofibromatosis type 1 (NF1, NF1 gene). Reports of non-SDHx HNP presentations are scarce and guidance for genetic testing nonexistent.nnnPATIENTS AND METHODSnAn international consortium registered patients with HNPs and performed mutation analyses of the SDHx, VHL, and RET genes. Those with SDHx germline mutations were excluded for purposes of this study. Personal and family histories were evaluated for paraganglial tumors, for the major tumor manifestations, and for family history of VHL, MEN2, or NF1.nnnRESULTSnTwelve patients were found to have hereditary non-SDHx HNPs of a total of 809 HNP and 2084 VHL registrants, 11 in the setting of germline VHL mutations and one of a RET mutation. The prevalence of hereditary HNP is five in 1000 VHL patients and nine in 1000 non-SDHx HNP patients. Comprehensive literature review revealed previous reports of HNPs in five VHL, two MEN2, and one NF1 patient. Overall, 11 here presented HNP cases, and four previously reported VHL-HNPs had lesions characteristic for VHL and/or a positive family history for VHL.nnnCONCLUSIONSnOur observations provide evidence that molecular genetic testing for VHL or RET germline mutations in patients with HNP should be done only if personal and/or family history shows evidence for one of these syndromes.

Multi-omics analysis defines core genomic alterations in pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas (PCCs/PGLs) are neural crest-derived tumours with a very strong genetic component. Here we report the first integrated genomic examination of a large collection of PCC/PGL. SNP array analysis reveals distinct copy-number patterns associated with genetic background. Whole-exome sequencing shows a low mutation rate of 0.3 mutations per megabase, with few recurrent somatic mutations in genes not previously associated with PCC/PGL. DNA methylation arrays and miRNA sequencing identify DNA methylation changes and miRNA expression clusters strongly associated with messenger RNA expression profiling. Overexpression of the miRNA cluster 182/96/183 is specific in SDHB-mutated tumours and induces malignant traits, whereas silencing of the imprinted DLK1-MEG3 miRNA cluster appears as a potential driver in a subgroup of sporadic tumours. Altogether, the complete genomic landscape of PCC/PGL is mainly driven by distinct germline and/or somatic mutations in susceptibility genes and reveals different molecular entities, characterized by a set of unique genomic alterations.

European consensus on the diagnosis and management of fibromuscular dysplasia

The main objectives of this expert consensus are to raise awareness about fibromuscular dysplasia, which is more frequent and more often systemic than previously thought and can sometimes have devastating consequences; to provide up-to-date recommendations for the diagnosis, evaluation, and management of the disease; and to identify research priorities. The emphasis has been put on recommendations for daily practice. The main topics covered include definition, classification, diagnosis, and management of fibromuscular dysplasia in adult patients with symptomatic involvement of the renal arteries, supra-aortic trunks, and digestive and peripheral arteries.

Rationale for anti-angiogenic therapy in pheochromocytoma and paraganglioma.

Pheochromocytomas and paragangliomas are highly vascularized tumors which are candidates for anti-angiogenic therapies. Several studies have reported the association of vascular endothelial growth factor (VEGF) overexpression with malignancy, but none took into account the genetic status of the patients or tumors, which may have a major influence on such observations. Transcriptome studies indeed revealed that pheochromocytomas and paragangliomas can be classified into two major clusters depending on their gene expression profile: Cluster 1 comprises samples associated with a hypoxic signature such as SDHx- and VHL-related tumors and cluster 2 includes RET, NF1, and TMEM127-mutated tumors, as well as most of sporadic tumors. The aim of this study was to provide a comprehensive rationale for the targeting of angiogenesis in patients with malignant forms of the disease. We used in situ hybridization, immunohistochemistry, and microarray gene expression profiling to evaluate angiogenesis and the expression of several angiogenic factors in a large cohort of pheochromocytomas and paragangliomas. We also studied the activation of mTOR by assessing the phosphorylation of its targets, P70 S6 kinase and 4E-BP1. These results were correlated with both malignancy and transcription signature. Our results reveal that cluster 1 tumors display a marked increase in both vascularization and in the expression of major angiogenic molecules, including VEGF, its receptors, HIF2α, Angiopoietin-2, and the endothelin receptors ETA and ETB. These overexpressions were observed in both benign and malignant samples of cluster 1 and thus appeared to be mainly dependent on the pseudo-hypoxic status of these tumors. The mTOR pathway was potentially activated in half of the tumors studied, with a slight increase in cluster 2 pheochromocytomas. Our results suggest that there is a strong rationale for anti-VEGF-based therapeutic strategies in malignant pheochromocytomas and paragangliomas, in particular in those associated with mutations in the SDHB gene.

Short-term effects of octreotide on blood pressure and plasma catecholamines and neuropeptide Y levels in patients with phaeochromocytoma: a placebo-controlled trial

OBJECTIVE The observation that phaeochromocytoma possess specific somatostatin binding sites led us to test the hypothesis that octreotide may have antisecretory potential in patients with phaeochromocytoma. We therefore compared the effects of octreotide and placebo on blood pressure and plasma catecholamines and neuropeptide Y. PATIENTS Ten consecutive patients referred to a tertiary care centre for the diagnosis and treatment of a phaeochromocytoma.

PHACTR1 Is a Genetic Susceptibility Locus for Fibromuscular Dysplasia Supporting Its Complex Genetic Pattern of Inheritance

Fibromuscular dysplasia (FMD) is a nonatherosclerotic vascular disease leading to stenosis, dissection and aneurysm affecting mainly the renal and cerebrovascular arteries. FMD is often an underdiagnosed cause of hypertension and stroke, has higher prevalence in females (~80%) but its pathophysiology is unclear. We analyzed ~26K common variants (MAF>0.05) generated by exome-chip arrays in 249 FMD patients and 689 controls. We replicated 13 loci (P<10−4) in 402 cases and 2,537 controls and confirmed an association between FMD and a variant in the phosphatase and actin regulator 1 gene (PHACTR1). Three additional case control cohorts including 512 cases and 669 replicated this result and overall reached the genomic level of significance (OR = 1.39, P = 7.4×10−10, 1,154 cases and 3,895 controls). The top variant, rs9349379, is intronic to PHACTR1, a risk locus for coronary artery disease, migraine, and cervical artery dissection. The analyses of geometrical parameters of carotids from ~2,500 healthy volunteers indicate higher intima media thickness (P = 1.97×10−4) and wall to lumen ratio (P = 0.002) in rs9349379-A carriers, suggesting indices of carotid hypertrophy previously described in carotids of FMD patients. Immunohistochemistry detected PHACTR1 in endothelium and smooth muscle cells of FMD and normal human carotids. The expression of PHACTR1 by genotypes in primary human fibroblasts showed higher expression in rs9349379-A carriers (N = 86, P = 0.003). Phactr1 knockdown in zebrafish resulted in dilated vessels indicating subtle impaired vascular development. We report the first susceptibility locus for FMD and provide evidence for a complex genetic pattern of inheritance and indices of shared pathophysiology between FMD and other cardiovascular and neurovascular diseases.

Progrès récents dans le diagnostic, l'évaluation pronostique et le traitement des phéochromocytomes

Resume Introduction. – Les pheochromocytomes sont des tumeurs secretant des catecholamines. Leur rarete requiert une demarche diagnostique par etapesxa0: depistage clinique, preuve biologique, localisation tumorale. Environ 10xa0% des cas sont ectopiques, 10xa0% familiaux, et 10xa0% d’evolution maligne. Les risques evolutifs dans les cas familiaux ou a risque de malignite justifient une enquete genetique, la recherche d’indicateurs pronostiques et une surveillance indefinie. Actualites et points forts. – Le test diagnostique le plus sensible est la mesure des metanephrines plasmatiques ou urinaires. La localisation tumorale repose sur la scanographie, l’imagerie par resonance magnetique et les scintigraphies specifiques. Les signes phenotypiques et les preuves genomiques de l’un des trois syndromes autosomiques dominants associes au pheochromocytome doivent etre recherches dans tous les cas. Ces cas familiaux sont souvent precoces, bilateraux et recidivants. Les pheochromocytomes peuvent etre malins d’emblee ou lors d’une recidive. Les metastases sont ganglionnaires, osseuses ou viscerales. Le risque de recidive croit avec la taille de la tumeur et le debit urinaire des metanephrines. Il est plus eleve dans les pheochromocytomes ectopiques ou ceux dont la secretion est immature. Ce risque justifie la surveillance clinique et biologique au moins biennale de tous les patients operes d’un pheochromocytome. Perspectives et projets. – L’etude des mecanismes de la tumorogenese et de l’hypersecretion du pheochromocytome est en rapide progres. Des progres sont egalement attendus dans le traitement des cas malinsxa0: chirurgie, embolisation des metastases viscerales, plastie percutanee des metastases osseuses, radiotherapie in situ par la meta-iodobenzylguanidine iodee, traitement antisecretoire par la metyrosine ou les analogues de la somatostatine.