Multi-omic analysis of SDHB-deficient pheochromocytomas and paragangliomas identifies metastasis and treatment-related molecular profiles.

Hereditary SDHB-mutant pheochromocytomas (PC) and paragangliomas (PG) are rare tumours with a high propensity to metastasize although their clinical behaviour is unpredictable. To characterize the genomic landscape of these tumours and identify metastasis biomarkers, we performed multi-omic analysis on 94 tumours from 79 patients using seven molecular methods. Sympathetic (chromaffin cell) and parasympathetic (non-chromaffin cell) PCPG had distinct molecular profiles reflecting their cell-of-origin and biochemical profile. TERT and ATRX-alterations were associated with metastatic PCPG and these tumours had an increased mutation load, and distinct transcriptional and telomeric features. Most PCPG had quiet genomes with some rare co-operative driver events observed, including EPAS1/HIF-2α mutations. Two mechanisms of acquired resistance to DNA alkylating chemotherapies were also detected - MGMT overexpression and mismatch repair-deficiency causing hypermutation. Our comprehensive multi-omic analysis of SDHB-mutant PCPG therefore identified features of metastatic disease and treatment response, expanding our understanding of these rare neuroendocrine tumours.

E-cadherin expression and gene expression profiles in corticotroph pituitary neuroendocrine tumor subtypes.

Corticotroph adenomas/pituitary neuroendocrine tumors (PitNETs) are associated with significant morbidity and mortality. Predictors of tumor behavior have not shown high prognostic accuracy. For somatotroph adenomas/PitNETs, E-cadherin expression correlates strongly with prognosis. E-cadherin expression has not been investigated in other PitNETs. A retrospective chart review of adults with corticotroph adenomas/PitNETs was conducted to assess correlation between E-cadherin expression and tumor characteristics. In addition, gene expression microarray was performed in subset of tumors (n = 16). Seventy-seven patients were identified; 71% were female, with median age of cohort 45.2 years. Seventy-five percent had macroadenomas, of which 22% were hormonally active. Ninety-five percent of microadenomas were hormonally active. Adrenocorticotropic hormone granulation pattern by IHC identified 63% as densely granulated (DG) and 34% as sparsely granulated (SG). All microadenomas were DG (p < .001); 50% of macroadenomas were DG associated with increased tumor invasion compared to SG. E-cadherin IHC was positive in 80%, diminished in 17%, and absent in 20% and did not correlate with corticotroph PitNETs subtype, size, or prognosis. In contrast to the distinct transcriptomes of corticotroph PitNETs and normal pituitaries, a comparison of clinically active and silent corticotroph PitNETs demonstrated similar molecular signatures indicating their common origin, but with unique differences related to their secretory status.

Patient-reported burden associated with pheochromocytoma/paraganglioma diagnosis.

Pheochromocytoma and paragangliomas (PPGLs) originate from the chromaffin cells of the adrenal medulla or neural crest progenitors outside the adrenal gland, respectively. The estimated annual incidence of PPGL is between 2.0 and 8.0/million adults. Minimal data exist on the impact of PPGL from the patient's perspective. Therefore, a survey was adapted from a previously published study on gastroenteropancreatic neuroendocrine tumors to explore the voice of patients with PPGL and learn ways to improve clinical care while understanding the current gaps to direct future research. A self-reported online survey was available to patients with PPGL and those with genetic predisposition even without PPGL from June to July 2022. Survey questions captured sociodemographic and clinical characteristics, the diagnostic workup, treatment and monitoring, quality and access to care, and financial impact. Here, we report the most relevant findings on patient experience of disease burden following diagnosis. A total of 270 people responded, the majority of whom were from the USA (79%), Caucasian (88%), and female (81%). The results of this survey highlight the burden of disease on a patient's daily life, resulting in moderate to severe financial distress, increased travel time to specialized facilities resulting in loss of work and wages, and significant delays in care. Respondents reported being unheard and unacknowledged. With a median time to diagnosis just over 2 years, the physical, mental, and emotional toll are substantial. Increasing access to PPGL specialists and centers could lead to faster diagnoses and better management, which may reduce the burden on both patients and healthcare centers.

A comprehensive characterisation of phaeochromocytoma and paraganglioma tumours through histone protein profiling, DNA methylation and transcriptomic analysis genome wide.

BACKGROUND: Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours. Pathogenic variants have been identified in more than 15 susceptibility genes; associated tumours are grouped into three Clusters, reinforced by their transcriptional profiles. Cluster 1A PPGLs have pathogenic variants affecting enzymes of the tricarboxylic acid cycle, including succinate dehydrogenase. Within inherited PPGLs, these are the most common. PPGL tumours are known to undergo epigenetic reprograming, and here, we report on global histone post-translational modifications and DNA methylation levels, alongside clinical phenotypes. RESULTS: Out of the 25 histone post-translational modifications examined, Cluster 1A PPGLs were distinguished from other tumours by a decrease in hyper-acetylated peptides and an increase in H3K4me2. DNA methylation was compared between tumours from individuals who developed metastatic disease versus those that did not. The majority of differentially methylated sites identified tended to be completely methylated or unmethylated in non-metastatic tumours, with low inter-sample variance. Metastatic tumours by contrast consistently had an intermediate DNA methylation state, including the ephrin receptor EPHA4 and its ligand EFNA3. Gene expression analyses performed to identify genes involved in metastatic tumour behaviour pin-pointed a number of genes previously described as mis-regulated in Cluster 1A tumours, as well as highlighting the tumour suppressor RGS22 and the pituitary tumour-transforming gene PTTG1. CONCLUSIONS: Combined transcriptomic and DNA methylation analyses revealed aberrant pathways, including ones that could be implicated in metastatic phenotypes and, for the first time, we report a decrease in hyper-acetylated histone marks in Cluster 1 PPGLs.

Diagnosis and Management of Pheochromocytomas and Paragangliomas: A Guide for the Clinician.

OBJECTIVE: The aim of this review was to provide a practical approach for clinicians regarding the diagnosis and management of pheochromocytomas and paragangliomas (PPGLs). METHODS: A literature search of PubMed was carried out using key words, including pheochromocytoma, paraganglioma, treatment, diagnosis, screening, and management. The discussion of diagnosis and management of PPGL is based on the evidence available from prospective studies when available and mostly from cohort studies, cross-sectional studies, and expert consensus. RESULTS: PPGL are neuroendocrine tumors arising from the chromaffin cells of adrenal medulla and sympathetic and parasympathetic ganglia, respectively. PPGL can be localized or metastatic, and they may secrete catecholamines, causing a variety of symptoms and potentially catastrophic and lethal complications if left untreated. The rarity of these tumors along with heterogeneous clinical presentation often poses challenges for the diagnosis and management. PPGL can be associated with several familial syndromes which are important to recognize. CONCLUSION: The last few years have witnessed an exponential growth in the knowledge around PPGL. This review aims at providing a comprehensive discussion of current concepts for clinicians regarding clinical presentation, diagnostic tools, and management strategies for PPGL.

Practical considerations when providing palliative care to patients with neuroendocrine tumors in the context of routine disease management or hospice care.

This serves as a white paper by the North American Neuroendocrine Tumor Society (NANETS) on the practical considerations when providing palliative care to patients with neuroendocrine tumors in the context of routine disease management or hospice care. The authors involved in the development of this manuscript represent a multidisciplinary team of patient advocacy, palliative care, and hospice care practitioners, endocrinologist, and oncologists who performed a literature review and provided expert opinion on a series of questions often asked by our patients and patient caregivers affected by this disease. We hope this document serves as a starting point for oncologists, palliative care teams, hospice medical teams, insurers, drug manufacturers, caregivers, and patients to have a frank, well-informed discussion of what a patient needs to maximize the quality of life during a routine, disease-directed care as well as at the end-of-life.

Multifocal Paraganglioma in Teenager Presenting With Hypertension.

Pediatric hypertension represents a rare though increasingly common medical problem. When encountered, a workup to determine the etiology should be conducted. In this report, we detail an unusual case in which a teenager presenting with hypertension was found to have multifocal primary paragangliomas. We illustrate important considerations in management which include appropriate preoperative labs and imaging, collaboration with endocrinology for preoperative alpha-blockade, surgical management with close perioperative hemodynamic control, and genetic evaluation for all patients with paragangliomas.

Single-nuclei and bulk-tissue gene-expression analysis of pheochromocytoma and paraganglioma links disease subtypes with tumor microenvironment.

Pheochromocytomas (PC) and paragangliomas (PG) are rare neuroendocrine tumors associated with autonomic nerves. Here we use single-nuclei RNA-seq and bulk-tissue gene-expression data to characterize the cellular composition of PCPG and normal adrenal tissues, refine tumor gene-expression subtypes and make clinical and genotypic associations. We confirm seven PCPG gene-expression subtypes with significant genotype and clinical associations. Tumors with mutations in VHL, SDH-encoding genes (SDHx) or MAML3-fusions are characterized by hypoxia-inducible factor signaling and neoangiogenesis. PCPG have few infiltrating lymphocytes but abundant macrophages. While neoplastic cells transcriptionally resemble mature chromaffin cells, early chromaffin and neuroblast markers are also features of some PCPG subtypes. The gene-expression profile of metastatic SDHx-related PCPG indicates these tumors have elevated cellular proliferation and a lower number of non-neoplastic Schwann-cell-like cells, while GPR139 is a potential theranostic target. Our findings therefore clarify the diverse transcriptional programs and cellular composition of PCPG and identify biomarkers of potential clinical significance.

Presentation, Management, and Outcomes of Urinary Bladder Paraganglioma: Results From a Multicenter Study.

CONTEXT: Urinary bladder paraganglioma (UBPGL) is rare. OBJECTIVE: We aimed to characterize the presentation and outcomes of patients diagnosed with UBPGL. METHODS: We conducted a multicenter study of consecutive patients with pathologically confirmed UBPGL evaluated between 1971 and 2021. Outcomes included repeat bladder surgery, metastases, and disease-specific mortality. RESULTS: Patients (n=110 total; n=56 [51%] women) were diagnosed with UBPGL at a median age of 50 years (interquartile range [IQR], 36-61 years). Median tumor size was 2 cm (IQR, 1-4 cm). UBPGL was diagnosed prior to biopsy in only 37 (34%), and only 69 (63%) patients had evaluation for catecholamine excess. In addition to the initial bladder surgery, 26 (25%) required multiple therapies, including repeat surgery in 10 (9%). Synchronous metastases were present in 9 (8%) patients, and 24 (22%) other patients with UBPGL developed metachronous metastases at a median of 4 years (IQR, 2-10 years) after the initial diagnosis. Development of metachronous metastases was associated with younger age (hazard ratio [HR] 0.97; 95% CI, 0.94-0.99), UBPGL size (HR 1.69; 95% CI, 1.31-2.17), and a higher degree of catecholamine excess (HR 5.48; 95% CI, 1.40-21.39). Disease-specific mortality was higher in patients with synchronous metastases (HR 20.80; 95% CI, 1.30-332.91). Choice of initial surgery, genetic association, sex, or presence of muscular involvement on pathology were not associated with development of metastases or mortality. CONCLUSIONS: Only a minority of patients were diagnosed before biopsy/surgery, reflecting need for better diagnostic strategies. All patients with UBPGL should have lifelong monitoring for development of recurrence and metastases.

Head and Neck Paragangliomas: An Update on the Molecular Classification, State-of-the-Art Imaging, and Management Recommendations.

Paragangliomas are neuroendocrine tumors that derive from paraganglia of the autonomic nervous system, with the majority of parasympathetic paragangliomas arising in the head and neck. More than one-third of all paragangliomas are hereditary, reflecting the strong genetic predisposition of these tumors. The molecular basis of paragangliomas has been investigated extensively in the past couple of decades, leading to the discovery of several molecular clusters and more than 20 well-characterized driver genes (somatic and hereditary), which are more than are known for any other endocrine tumor. Head and neck paragangliomas are largely related to the pseudohypoxia cluster and have been previously excluded from most molecular profiling studies. This review article introduces the molecular classification of paragangliomas, with a focus on head and neck paragangliomas, and discusses its impact on the management of these tumors. Genetic testing is now recommended for all patients with paragangliomas to provide screening and surveillance recommendations for patients and relatives. While CT and MRI provide excellent anatomic characterization of paragangliomas, gallium 68 tetraazacyclododecane tetraacetic acid-octreotate (ie, 68Ga-DOTATATE) has superior sensitivity and is recommended as first-line imaging in patients with head and neck paragangliomas with concern for multifocal and metastatic disease, patients with known multifocal and metastatic disease, and in candidates for targeted peptide-receptor therapy. Keywords: Molecular Imaging, MR Perfusion, MR Spectroscopy, Neuro-Oncology, PET/CT, SPECT/CT, Head/Neck, Genetic Defects © RSNA, 2022.

SDHB knockout and succinate accumulation are insufficient for tumorigenesis but dual SDHB/NF1 loss yields SDHx-like pheochromocytomas.

Inherited pathogenic succinate dehydrogenase (SDHx) gene mutations cause the hereditary pheochromocytoma and paraganglioma tumor syndrome. Syndromic tumors exhibit elevated succinate, an oncometabolite that is proposed to drive tumorigenesis via DNA and histone hypermethylation, mitochondrial expansion, and pseudohypoxia-related gene expression. To interrogate this prevailing model, we disrupt mouse adrenal medulla SDHB expression, which recapitulates several key molecular features of human SDHx tumors, including succinate accumulation but not 5hmC loss, HIF accumulation, or tumorigenesis. By contrast, concomitant SDHB and the neurofibromin 1 tumor suppressor disruption yields SDHx-like pheochromocytomas. Unexpectedly, in vivo depletion of the 2-oxoglutarate (2-OG) dioxygenase cofactor ascorbate reduces SDHB-deficient cell survival, indicating that SDHx loss may be better tolerated by tissues with high antioxidant capacity. Contrary to the prevailing oncometabolite model, succinate accumulation and 2-OG-dependent dioxygenase inhibition are insufficient for mouse pheochromocytoma tumorigenesis, which requires additional growth-regulatory pathway activation.

Pheochromocytoma and paraganglioma: germline genetics and hereditary syndromes.

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are neuroendocrine tumors arising from the adrenal medulla and extra-adrenal ganglia, respectively. Approximately 15-25% of PCC/PGL can become metastatic. Up to 30-40% of patients with PCC/PGL have a germline pathogenic variant in a known susceptibility gene for PCC/PGL; therefore, all patients with PCC/PGL should undergo clinical genetic testing. Most of the susceptibility genes are associated with variable penetrance for PCC/PGL and are associated with different syndromes, which include susceptibility for other tumors and conditions. The objective of this review is to provide an overview of the germline susceptibility genes for PCC/PGL, the associated clinical syndromes, and recommended surveillance.

Pathological and Genetic Stratification for Management of Adrenocortical Carcinoma.

CONTEXT: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy that affects patients across the age spectrum. Although the overall survival in patients with ACC is poor, there is significant heterogeneity in terms of outcomes, presentation, and underlying genetic drivers. EVIDENCE ACQUISITION: This review is based on the evidence collected from primary research studies, expert reviews, and published guidelines. The studies were identified through PubMed search with key words "adrenocortical carcinoma," "prognosis," "pathology," and "genetics." The PubMed search was complemented by authors' expertise, research, and clinical experience in the field of ACC. EVIDENCE SYNTHESIS: Identification of biomarkers has been critical to gain better insight into tumor behavior and to guide therapeutic approach to patients. Tumor stage, resection status, and Ki67 are pathological tumor characteristics that have been identified as prognosticators in patients with ACC. Cortisol excess also correlates with worse prognosis. Clinical and histopathological characteristics help stratify patient outcomes, yet still up to 25% of patients have a different outcome than predicted. To bridge this gap, comprehensive genomic profiling studies have characterized additional profiles that correlate with clinical outcomes. In addition, studies of clinically applicable molecular markers are under way to further stratify outcomes in patients with ACC tumors. CONCLUSIONS: Clinical predictors in combination with pathological markers play a critical role in the approach to patients with ACC. Recent advances in genetic prognosticators will help extend the stratification of these tumors and contribute to a personalized therapeutic approach to patients with ACC.

Targeted genomic analysis of 364 adrenocortical carcinomas.

Despite recent advances in elucidating molecular pathways underlying adrenocortical carcinoma (ACC), this orphan malignancy is associated with poor survival. Identification of targetable genomic alterations is critical to improve outcomes. The objective of this study was to characterize the genomic profile of a large cohort of patient ACC samples to identify actionable genomic alterations. Three hundred sixty-four individual patient ACC tumors were analyzed. The median age of the cohort was 52 years and 60.9% (n = 222) were female. ACC samples had common alterations in epigenetic pathways with 38% of tumors carrying alterations in genes involved in histone modification, 21% in telomere lengthening, and 21% in SWI/SNF complex. Tumor suppressor genes and WNT signaling pathway were each mutated in 51% of tumors. Fifty (13.7%) ACC tumors had a genomic alteration in genes involved in the DNA mismatch repair (MMR) pathway with many tumors also displaying an unusually high number of mutations and a corresponding MMR mutation signature. In addition, genomic alterations in several genes not previously associated with ACC were observed, including IL7R, LRP1B, FRS2 mutated in 6, 8 and 4% of tumors, respectively. In total, 58.5% of ACC (n = 213) had at least one potentially actionable genomic alteration in 46 different genes. As more than half of ACC have one or more potentially actionable genomic alterations, this highlights the value of targeted sequencing for this orphan cancer with a poor prognosis. In addition, significant incidence of MMR gene alterations suggests that immunotherapy is a promising therapeutic for a considerable subset of ACC patients.

Correlation Between Plasma Catecholamines, Weight, and Diabetes in Pheochromocytoma and Paraganglioma.

CONTEXT: Pheochromocytomas and paragangliomas (PCC/PGL) are neuroendocrine tumors with discrete catecholamine profiles that cause incompletely understood metabolic and physiologic changes. OBJECTIVE: The objective was to evaluate relationships between plasma catecholamines, body weight, and hemoglobin A1c (HbA1c). We hypothesized that individual catecholamines would correlate negatively with weight and glucose control. DESIGN: A retrospective cohort study was performed (1999-2020). Wilcoxon rank-sum tests compared nonparametric, continuous variables; mixed-effect linear modeling (MEM) evaluated relationships between catecholamines and weight or HbA1c. The median study duration was 54.2 months [interquartile range (IQR) 19.0-95.1]. SETTING: Tertiary academic hospital. PATIENTS: 360 patients were identified prospectively by referral to our center for management or surveillance of PCC/PGL. The median age was 59 years (IQR 45-67) and 56.4% (n = 203) were female. MAIN OUTCOME MEASURES: The primary and secondary outcomes were weight and HbA1c, respectively. RESULTS: On multivariable MEM, norepinephrine (P < 0.0005) negatively correlated with weight when all catecholamines and their derivatives were tried in the model, and normetanephrine (P < 0.0005) correlated when only metanephrines were included. In the surgical cohort (n = 272), normetanephrine decreased postoperatively and was inversely associated with weight (P < 0.0005). Elevated norepinephrine or normetanephrine at the study termination, indicative of metastatic and/or recurrent disease (MRD), correlated with weight loss. Norepinephrine and normetanephrine (P < 0.0005) directly correlated with HbA1c. CONCLUSION: Plasma norepinephrine and its metabolite directly correlate with HbA1c and inversely correlate with weight in PCC/PGL. After resection, declining normetanephrine levels correlate with improving HbA1c despite an increase in patient body weight. Persistently elevated catecholamines and decreasing weight are observed in MRD.

Mastermind Like Transcriptional Coactivator 3 (MAML3) Drives Neuroendocrine Tumor Progression.

Metastatic disease in pheochromocytomas and paragangliomas (PCC/PGL) is not well-understood. The Cancer Genome Atlas discovered recurrent MAML3 fusion genes in a subset of tumors that lacked known germline or somatic driver mutations and were associated with aggressive disease. Here, we aimed to investigate the role of MAML3 in tumorigenesis. Human PCC/PGLs were used for IHC and genetic analysis. Three neuroendocrine tumor cell lines, SK-N-SH, QGP-1, and BON-1, were transiently transfected with MAML3 (FL) or exon 1 deleted MAML3 (dEx1; mimicking the fusion), and biologic effects of overexpression were examined in vitro. We found 7% (4/55) of human PCC/PGL have UBTF∼MAML3 fusions and all were sporadic cases with metastatic disease. Fusion-positive tumors had intense MAML3 nuclear staining and increased ß-catenin by IHC and showed increased WNT4 expression. In vitro, overexpression of FL and dEx1 MAML3 increased invasion in SK-N-SH, QGP-1, and BON-1 (all P < 0.05) and increased soft-agar colony formation in QGP-1 and BON-1 (all P < 0.05). Cotransfection with FL or dEx1 MAML3 and ß-catenin increased TCF/LEF promoter activation by luciferase activity and coimmunoprecipitation confirmed interaction between MAML3 and ß-catenin. These data suggest MAML3 is involved in WNT signaling pathway activation. In summary, UBTF∼MAML3 fusions are present in a subset of PCC/PGL and associated with metastatic disease without other known drivers. MAML3 overexpression led to increased tumorigenicity in neuroendocrine tumor cells and the mechanism of action may involve WNT signaling pathways. IMPLICATIONS: MAML3 increases tumorigenicity and invasion in neuroendocrine tumor cells and may be a prognostic marker for aggressive disease.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma.

ABSTRACT: This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

Genetics of pheochromocytoma and paraganglioma.

PURPOSE OF REVIEW: This review summarizes our current understanding of germline and somatic genetics and genomics of pheochromocytomas and paragangliomas (PCC/PGL), describes existing knowledge gaps, and discusses future research directions. RECENT FINDINGS: Germline pathogenic variants (PVs) are found in up to 40% of those with PCC/PGL. Tumors with germline PVs are broadly categorized as Cluster 1 (pseudohypoxia), including those with SDH, VHL, FH, and EPAS1 PVs, or Cluster 2 (kinase signaling) including those with NF1, RET, TMEM127, and MAX PVs. Somatic driver mutations exist in some of the same genes (RET, VHL, NF1, EPAS1) as well as in additional genes including HRAS, CSDE1 and genes involved in cell immortalization (ATRX and TERT). Other somatic driver events include recurrent fusion genes involving MAML3. SUMMARY: PCC/PGL have the highest association with germline PVs of all human solid tumors. Expanding our understanding of the molecular pathogenesis of PCC/PGL is essential to advancements in diagnosis and surveillance and the development of novel therapies for these unique tumors.