Children with MEN1 gene mutations may present first (and at a young age) with Cushing disease

Progress report on multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) syndrome is an autosomal dominant disorder caused by a germline pathogenic variant in the MEN1 tumor suppressor gene. Patients with MEN1 have a high risk for primary hyperparathyroidism (PHPT) with a penetrance of nearly 100%, pituitary adenomas (PitAd) in 40% of patients, and neuroendocrine neoplasms (NEN) of the pancreas (40% of patients), duodenum, lung, and thymus. Increased MEN1-related mortality is mainly related to duodenal-pancreatic and thymic NEN. Management of PHPT differs from that of patients with sporadic disease, as the surgical approach in MEN1-related PHPT includes near-total or total parathyroidectomy because of multigland hyperplasia in most patients and the consequent high risk of recurrence. NEN management also differs from patients with sporadic disease due to multiple synchronous and metasynchronous neoplasms. In addition, the lifelong risk of developing NEN requires special considerations to avoid excessive surgeries and to minimize damage to the patient's function and well-being. This progress report will outline current insights into surveillance and management of the major clinical manifestation of MEN1 syndrome in children and adults with MEN1 diagnosis. In addition, we will discuss MEN1-like clinical presentation with negative MEN1-genetic workup and future clinical and research directions.

An Update on the Genetic Drivers of Corticotroph Tumorigenesis

The genetic landscape of corticotroph tumours of the pituitary gland has dramatically changed over the last 10 years. Somatic changes in the USP8 gene account for the most common genetic defect in corticotrophinomas, especially in females, while variants in TP53 or ATRX are associated with a subset of aggressive tumours. Germline defects have also been identified in patients with Cushing's disease: some are well-established (MEN1, CDKN1B, DICER1), while others are rare and could represent coincidences. In this review, we summarise the current knowledge on the genetic drivers of corticotroph tumorigenesis, their molecular consequences, and their impact on the clinical presentation and prognosis.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) for the diagnosis of Cushing's syndrome: Genetics of Cushing's syndrome

Cushing's syndrome is due to overproduction of cortisol, leading to abnormal and prolonged exposure to cortisol. The most common etiology is Cushing disease, while adrenal causes are rarer. Knowledge of the genetics of Cushing's syndrome, and particularly the adrenal causes, has improved considerably over the last 10 years, thanks in particular to technical advances in high-throughput sequencing. The present study, by a group of experts from the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology, reviewed the literature on germline genetic alterations leading to a predisposition to develop Cushing's syndrome. The review led to a consensus statement on genetic screening for Cushing disease and adrenal Cushing's syndrome.

Identification and validation of cortisol-related hub biomarkers and the related pathogenesis of biomarkers in Ischemic Stroke

BACKGROUND

Ischemic stroke is a disease in which cerebral blood flow is blocked due to various reasons, leading to ischemia, hypoxia, softening, and even necrosis of brain tissues. The level of cortisol is related to the occurrence and progression of ischemic stroke. However, the mechanism governing their interrelationship is still unclear. The main objective of this study was to identify and understand the molecular mechanism between cortisol and IS.

METHODS

The common cortisol-related biological processes were screened by mutual verification of two data sets and the cortisol-related hub biomarkers were identified. Modular analysis of protein interaction networks was performed, and the differential pathway analysis of individual genes was conducted by GSVA and GSEA. Drug and transcription factor regulatory networks of hub genes were excavated, and the diagnostic potential of hub genes was analyzed followed by the construction of a diagnostic model.

RESULTS

By screening the two data sets by GSVA, three biological processes with common differences were obtained. After variation analysis, four cortisol-related hub biomarkers (CYP1B1, CDKN2B, MEN1, and USP8) were selected. Through the modular analysis of the protein-protein interaction network and double verification of GSVA and GSEA, a series of potential molecular mechanisms of hub genes were discovered followed by a series of drug regulatory networks and transcription factor regulatory networks. The hub biomarkers were found to have a high diagnostic value by ROC; thus, a diagnostic model with high diagnostic efficiency was constructed. The diagnostic value was mutually confirmed in the two data sets.

CONCLUSION

Four cortisol-related hub biomarkers are identified in this study, which provides new ideas for the key changes of cortisol during the occurrence of IS.

Pediatric Macrocorticotropinoma: Do They Differ from Microcorticotropinoma?

INTRODUCTION

Cushing's disease (CD) due to macrocorticotropinoma (MC) in children and adolescents is a rare entity with limited information regarding its characteristics. The objective of the study is to describe the clinical, biochemical, imaging, management, outcome, and genetic characteristics of children and adolescents with CD due to MC and compare them with those of microcorticotropinoma (mc).

METHODS

This retrospective study was conducted at a single tertiary care center. Thirty-two patients with CD and MC (maximum tumor dimension ≥10 mm on imaging) and 65 patients with mc (<10 mm on imaging) aged ≤20 years at presentation were enrolled.

RESULTS

Nineteen girls and 13 boys with MC presented at a median (IQR) age of 14.5 (12.0-17.9) years. Patients with MC had higher body mass index-standard deviation score (BMI-SDS) (3.70 ± 2.60 vs. 2.59 ± 2.01, p = 0.04), more frequent neuro-ophthalmic symptoms (25% vs. 9% p = 0.04) and short stature (59% vs. 34%, p = 0.049) but less frequent livid striae (53% vs. 77%, p = 0.01), hypokalemia (12% vs. 36%, p = 0.04), and lower cortisol (nmol/L) to corticotropin (pmol/L) ratio (41.20 vs. 55.74, p = 0.04) than those with mc. The remission (59% vs. 64%, p = 1.0) and relapse (53% vs. 37%, p = 0.26) rates after first-line surgery and remission rate after radiotherapy (RT) were comparable between the two cohorts, whereas time to remission after RT (27 vs. 13 months, p = 0.05) was longer in the MC group. A patient with MC had a pathogenic germline variant in CDH23.

CONCLUSION

In this large monocentric series of pediatric CD, frequent mass effect symptoms and short stature, higher BMI-SDS, less frequent livid striae, and hypokalemia with lower effective cortisol secretion characterize the MC cohort. The outcomes of surgery and RT were similar between the groups except for a longer time to remission after RT in the MC cohort. Germline variants are rare (4%) in pediatric MC.

Expressions of Cushing's syndrome in multiple endocrine neoplasia type 1

Cushing's syndrome (CS) resulting from endogenous hypercortisolism can be sporadic or can occur in the context of familial disease because of pituitary or extra-pituitary neuroendocrine tumors. Multiple endocrine neoplasia type 1 (MEN1) is unique among familial endocrine tumor syndromes because hypercortisolism in this context can result from pituitary, adrenal, or thymic neuroendocrine tumors and can therefore reflect either ACTH-dependent or ACTH-independent pathophysiologies. The prominent expressions of MEN1 include primary hyperparathyroidism, tumors of the anterior pituitary, gastroenteropancreatic neuroendocrine tumors, and bronchial carcinoid tumors along with several common non-endocrine manifestations such as cutaneous angiofibromas and leiomyomas. Pituitary tumors are present in about 40% of MEN1 patients, and up to 10% of such tumors secrete ACTH that can result in Cushing's disease. Adrenocortical neoplasms occur frequently in MEN1. Although such adrenal tumors are mostly clinically silent, this category can include benign or malignant tumors causing hypercortisolism and CS. Ectopic tumoral ACTH secretion has also been observed in MEN1, almost exclusively originating from thymic neuroendocrine tumors. The range of clinical presentations, etiologies, and diagnostic challenges of CS in MEN1 are reviewed herein with an emphasis on the medical literature since 1997, when the MEN1 gene was identified.

An update on, and genetics of refractory adenomas of childhood

Pituitary adenomas in childhood tend to be more frequently due to germline genetic changes and are often diagnosed at late stages due to delayed recognition by pediatricians and other caretakers who are not familiar with this rare disease in childhood. As a result, often, pediatric pituitary adenomas are aggressive or remain refractory to treatment. In this review, we discuss germline genetic defects that account for the most common pediatric pituitary adenomas that are refractory to treatment. We also discuss some somatic genetic events, such as chromosomal copy number changes that characterize some of the most aggressive pituitary adenomas in childhood that end up being refractory to treatment.

Genetic drivers of Cushing's disease: Frequency and associated phenotypes

PURPOSE

Cushing's disease (CD) is often explained by a single somatic sequence change. Germline defects, however, often go unrecognized. We aimed to determine the frequency and associated phenotypes of genetic drivers of CD in a large cohort.

METHODS

We studied 245 unrelated patients with CD (139 female, 56.7%), including 230 (93.9%) pediatric and 15 (6.1%) adult patients. Germline exome sequencing was performed in 184 patients; tumor exome sequencing was also done in 27 of them. A total of 43 germline samples and 92 tumor samples underwent Sanger sequencing of specific genes. Rare variants of uncertain significance, likely pathogenic (LP), or pathogenic variants in CD-associated genes, were identified.

RESULTS

Germline variants (13 variants of uncertain significance, 8 LP, and 11 pathogenic) were found in 8 of 19 patients (42.1%) with positive family history and in 23 of 226 sporadic patients (10.2%). Somatic variants (1 LP and 7 pathogenic) were found in 20 of 119 tested individuals (16.8%); one of them had a coexistent germline defect. Altogether, variants of interest were identified at the germline level in 12.2% of patients, at the somatic level in 7.8%, and coexisting germline and somatic variants in 0.4%, accounting for one-fifth of the cohort.

CONCLUSION

We report an estimate of the contribution of multiple germline and somatic genetic defects underlying CD in a single cohort.

Genetic Basis of ACTH-Secreting Adenomas

Cushing's disease represents 60-70% of all cases of Cushing's syndrome, presenting with a constellation of clinical features associated with sustained hypercortisolism. Molecular alterations in corticotrope cells lead to the formation of ACTH-secreting adenomas, with subsequent excessive production of endogenous glucocorticoids. In the last few years, many authors have contributed to analyzing the etiopathogenesis and pathophysiology of corticotrope adenomas, which still need to be fully clarified. New molecular modifications such as somatic mutations of USP8 and other genes have been identified, and several case series and case reports have been published, highlighting new molecular alterations that need to be explored. To investigate the current knowledge of the genetics of ACTH-secreting adenomas, we performed a bibliographic search of the recent scientific literature to identify all pertinent articles. This review presents the most recent updates on somatic and germline mutations underlying Cushing's disease. The prognostic implications of these mutations, in terms of clinical outcomes and therapeutic scenarios, are still debated. Further research is needed to define the clinical features associated with the different genotypes and potential pharmacological targets.

Multiple endocrine neoplasia type 1 combined with thyroid neoplasm: A case report and review of literatures

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and presents mostly as parathyroid, endocrine pancreas (such as gastrinoma) and anterior pituitary tumors. At present, papillary thyroid carcinoma (PTC) and nodular goiter are not regarded as components of MEN1.

CASE SUMMARY

A 35-year-old woman presented with MEN1 accompanied by coinstantaneous PTC and nodular goiter. The pathological diagnosis was PTC with cervical lymph node metastasis, nodular goiter, parathyroid cyst and adenomatoid hyperplasia. Genetic testing was performed and a MEN1 gene mutation was detected. The patient underwent unilateral lobectomy of the thyroid gland and surgical removal of the parathyroid tumors. At 18 mo of follow-up, ultrasonic examination of the neck showed no abnormality. Serum calcium and parathyroid hormone levels were normal. No new MEN1-associated tumors were detected.

CONCLUSION

The role of inactivating mutations of MEN1 gene in tumorigenesis of PTC and/or nodular goiter remains to be determined by more case reports and further research.

Beyond the "3 Ps": A critical appraisal of the non-endocrine manifestations of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1), an autosomal-dominantly inherited tumor syndrome, is classically defined by tumors arising from the "3 Ps": Parathyroids, Pituitary, and the endocrine Pancreas. From its earliest descriptions, MEN1 has been associated with other endocrine and non-endocrine neoplastic manifestations. High quality evidence supports a direct association between pathogenic MEN1 variants and neoplasms of the skin (angiofibromas and collagenomas), adipose tissue (lipomas and hibernomas), and smooth muscle (leiomyomas). Although CNS tumors, melanoma, and, most recently, breast cancer have been reported as MEN1 clinical manifestations, the published evidence to date is not yet sufficient to establish causality. Well-designed, multicenter prospective studies will help us to understand better the relationship of these tumors to MEN1, in addition to verifying the true prevalence and penetrance of the well-documented neoplastic associations. Nevertheless, patients affected by MEN1 should be aware of these non-endocrine manifestations, and providers should be encouraged always to think beyond the "3 Ps" when treating an MEN1 patient.

Consensus on diagnosis and management of Cushing's disease: a guideline update

Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

Clinical aspects of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome characterized by the co-occurrence of primary hyperparathyroidism, duodenopancreatic neuroendocrine tumours (NETs) and/or pituitary adenomas. MEN1 can predispose patients to other endocrine and non-endocrine tumours, such as cutaneous tumours, central nervous system tumours and breast cancer. Endocrine tumours in patients with MEN1 differ from sporadic tumours in that they have a younger age at onset, present as multiple tumours in the same organ and have a different clinical course. Therefore, patients with overt MEN1 and those who carry a MEN1 mutation should be offered tailored biochemical and imaging screening to detect tumours and evaluate their progression over time. Fortunately, over the past 10 years, knowledge about the clinical phenotype of these tumours has markedly progressed, thanks to the implementation of national registries, particularly in France and the Netherlands. This Review provides an update on the clinical management of MEN1-related tumours. Epidemiology, the clinical picture, diagnostic work-up and the main lines of treatment for MEN1-related tumours are summarized. Controversial therapeutic aspects and issues that still need to be addressed are also discussed. Moreover, special attention is given to MEN1 manifestations in children and adolescents.

Germline CDKN1B Loss-of-Function Variants Cause Pediatric Cushing's Disease With or Without an MEN4 Phenotype

CONTEXT

Germline loss-of-function CDKN1B gene variants cause the autosomal dominant syndrome of multiple endocrine neoplasia type 4 (MEN4). Even though pituitary neuroendocrine tumors are a well-known component of the syndrome, only 2 cases of Cushing's disease (CD) have so far been described in this setting.

AIM

To screen a large cohort of CD patients for CDKN1B gene defects and to determine their functional effects.

PATIENTS

We screened 211 CD patients (94.3% pediatric) by germline whole-exome sequencing (WES) only (n = 157), germline and tumor WES (n = 27), Sanger sequencing (n = 6), and/or germline copy number variant (CNV) analysis (n = 194). Sixty cases were previously unpublished. Variant segregation was investigated in the patients' families, and putative pathogenic variants were functionally characterized.

RESULTS

Five variants of interest were found in 1 patient each: 1 truncating (p.Q107Rfs*12) and 4 nontruncating variants, including 3 missense changes affecting the CDKN1B protein scatter domain (p.I119T, p.E126Q, and p.D136G) and one 5' untranslated region (UTR) deletion (c.-29_-26delAGAG). No CNVs were found. All cases presented early (10.5 ± 1.3 years) and apparently sporadically. Aside from colon adenocarcinoma in 1 carrier, no additional neoplasms were detected in the probands or their families. In vitro assays demonstrated protein instability and disruption of the scatter domain of CDKN1B for all variants tested.

CONCLUSIONS

Five patients with CD and germline CDKN1B variants of uncertain significance (n = 2) or pathogenic/likely pathogenic (n = 3) were identified, accounting for 2.6% of the patients screened. Our finding that germline CDKN1B loss-of-function may present as apparently sporadic, isolated pediatric CD has important implications for clinical screening and genetic counselling.

Aggressive pituitary tumors in the young and elderly

Aggressive pituitary tumors (APTs) represent rare pituitary adenomas (PAs) with local invasion of surrounding tissues, increased risk for multiple recurrence, rapid tumor growth, or resistance to standard therapies. The most common APTs in children and adolescents are giant prolactinomas and somatotropinomas. Few cases of Crooke's cell adenomas, silent corticotroph adenomas and pituitary carcinomas have also been reported in the literature. Pediatric patients with APTs have higher risk of harboring germline genetic defects, most commonly in the MEN1 and AIP genes. Since certain genetic defects confer a more aggressive behavior to PAs, genetic testing should be considered in tumors with young onset and positive family history. The management of pediatric APTs involves usually a combination of standard therapies (surgical, medical, radiation). Newer agents, such as temozolomide, have been used in few cases of pediatric pituitary tumors with promising results. In the elderly, PAs are more commonly non-functioning. Their management often poses dilemmas given the coexistence of age-related comorbidities. However, standard surgical treatment and temozolomide seem to be safe and well tolerated in elderly patients.

Cushing syndrome: Old and new genes

Cushing syndrome (CS) describes the signs and symptoms caused by exogenous or endogenous hypercortisolemia. Endogenous CS is caused by either ACTH-dependent sources (pituitary or ectopic) or ACTH-independent (adrenal) hypercortisolemia. Several genes are currently known to contribute to the pathogenesis of CS. Germline gene defects, such as MEN1, AIP, PRKAR1A and others, often present in patients with pituitary or adrenal involvement as part of a genetic syndrome. Somatic defects in genes, such as USP8, TP53, and others, are also involved in the development of pituitary or adrenal tumors in a large percentage of patients with CS, and give insight in pathways involved in pituitary or adrenal tumorigenesis.

Rare Germline DICER1 Variants in Pediatric Patients With Cushing's Disease: What Is Their Role?

Context: The DICER1 syndrome is a multiple neoplasia disorder caused by germline mutations in the DICER1 gene. In DICER1 patients, aggressive congenital pituitary tumors lead to neonatal Cushing's disease (CD). The role of DICER1 in other corticotropinomas, however, remains unknown. Objective: To perform a comprehensive screening for DICER1 variants in a large cohort of CD patients, and to analyze their possible contribution to the phenotype. Design, setting, patients, and interventions: We included 192 CD cases: ten young-onset (age <30 years at diagnosis) patients were studied using a next generation sequencing panel, and 182 patients (170 pediatric and 12 adults) were screened via whole-exome sequencing. In seven cases, tumor samples were analyzed by Sanger sequencing. Results: Rare germline DICER1 variants were found in seven pediatric patients with no other known disease-associated germline defects or somatic DICER1 second hits. By immunohistochemistry, DICER1 showed nuclear localization in 5/6 patients. Variant transmission from one of the parents was confirmed in 5/7 cases. One patient had a multinodular goiter; another had a family history of melanoma; no other patients had a history of neoplasms. Conclusions: Our findings suggest that DICER1 gene variants may contribute to the pathogenesis of non-syndromic corticotropinomas. Clarifying whether DICER1 loss-of-function is disease-causative or a mere disease-modifier in this setting, requires further studies. Clinical trial registration: ClinicalTrials.gov: NCT00001595.

The Genetics of Pituitary Adenomas

The genetic landscape of pituitary adenomas (PAs) is diverse and many of the identified cases remain of unclear pathogenetic mechanism. Germline genetic defects account for a small percentage of all patients and may present in the context of relevant family history. Defects in AIP (mutated in Familial Isolated Pituitary Adenoma syndrome or FIPA), MEN1 (coding for menin, mutated in Multiple Endocrine Neoplasia type 1 or MEN 1), PRKAR1A (mutated in Carney complex), GPR101 (involved in X-Linked Acrogigantism or X-LAG), and SDHx (mutated in the so called "3 P association" of PAs with pheochromocytomas and paragangliomas or 3PAs) account for the most common familial syndromes associated with PAs. Tumor genetic defects in USP8, GNAS, USP48 and BRAF are some of the commonly encountered tissue-specific changes and may explain a larger percentage of the developed tumors. Somatic (at the tumor level) genomic changes, copy number variations (CNVs), epigenetic modifications, and differential expression of miRNAs, add to the variable genetic background of PAs.