Adrenocortical carcinomas (ACCs) are aggressive cancers originating in the cortex of the adrenal gland. Despite overall poor prognosis, ACC outcome is heterogeneous. We performed exome sequencing and SNP array analysis of 45 ACCs and identified recurrent alterations in known driver genes (CTNNB1, TP53, CDKN2A, RB1 and MEN1) and in genes not previously reported in ACC (ZNRF3, DAXX, TERT and MED12), which we validated in an independent cohort of 77 ACCs. ZNRF3, encoding a cell surface E3 ubiquitin ligase, was the most frequently altered gene (21%) and is a potential new tumor suppressor gene related to the β-catenin pathway. Our integrated genomic analyses further identified two distinct molecular subgroups with opposite outcome. The C1A group of ACCs with poor outcome displayed numerous mutations and DNA methylation alterations, whereas the C1B group of ACCs with good prognosis displayed specific deregulation of two microRNA clusters. Thus, aggressive and indolent ACCs correspond to two distinct molecular entities driven by different oncogenic alterations.
Epstein-Barr virus (EBV) positive diffuse large B-cell lymphoma (DLBCL) of the elderly, initially described in 2003, is a provisional entity in the 2008 World Health Organization classification system and is defined as an EBV-positive monoclonal large B-cell proliferation that occurs in patients >50 years of age and in whom there is no known immunodeficiency or history of lymphoma. These tumors are more common in Asia but also occur in North America and Europe at a low frequency. These neoplasms exhibit a morphologic continuum, from polymorphous to monomorphous, but morphologic features do not correlate with prognosis as all patients have a clinically aggressive course. Most EBV-positive DLBCL of the elderly patients have an activated B-cell immunophenotype and are characterized by prominent nuclear factor-κB activation. Cytogenetic complexity is usually low. In this review, we comprehensively delineate the data emerging from analyses of EBV latency program, microRNA-mediated EBV viral oncogenesis, functional genomics of EBV and its biology, and differential diagnosis challenge for EBV-positive DLBCL of the elderly. It is hoped that the improved understanding of these tumors will lead to the development of novel therapeutic approaches, enhance the effectiveness of clinical trials, and improve prognosis.
Supplemental Digital Content is available in the text.
Summary Background Cross-sectional imaging regularly results in incidental discovery of adrenal tumours, requiring exclusion of adrenocortical carcinoma (ACC). However, differentiation is hampered by poor specificity of imaging characteristics. We aimed to validate a urine steroid metabolomics approach, using steroid profiling as the diagnostic basis for ACC. Methods We did a prospective multicentre study in adult participants (age ≥18 years) with newly diagnosed adrenal masses. We assessed the accuracy of diagnostic imaging strategies based on maximum tumour diameter (≥4 cm vs <4 cm), imaging characteristics (positive vs negative), and urine steroid metabolomics (low, medium, or high risk of ACC), separately and in combination, using a reference standard of histopathology and follow-up investigations. With respect to imaging characteristics, we also assessed the diagnostic utility of increasing the unenhanced CT tumour attenuation threshold from the recommended 10 Hounsfield units (HU) to 20 HU. Findings Of 2169 participants recruited between Jan 17, 2011, and July 15, 2016, we included 2017 from 14 specialist centres in 11 countries in the final analysis. 98 (4·9%) had histopathologically or clinically and biochemically confirmed ACC. Tumours with diameters of 4 cm or larger were identified in 488 participants (24·2%), including 96 of the 98 with ACC (positive predictive value [PPV] 19·7%, 95% CI 16·2–23·5). For imaging characteristics, increasing the unenhanced CT tumour attenuation threshold to 20 HU from the recommended 10 HU increased specificity for ACC (80·0% [95% CI 77·9–82·0] vs 64·0% [61·4–66.4]) while maintaining sensitivity (99·0% [94·4–100·0] vs 100·0% [96·3–100·0]; PPV 19·7%, 16·3–23·5). A urine steroid metabolomics result indicating high risk of ACC had a PPV of 34·6% (95% CI 28·6–41·0). When the three tests were combined, in the order of tumour diameter, positive imaging characteristics, and urine steroid metabolomics, 106 (5·3%) participants had the result maximum tumour diameter of 4 cm or larger, positive imaging characteristics (with the 20 HU cutoff), and urine steroid metabolomics indicating high risk of ACC, for which the PPV was 76·4% (95% CI 67·2–84·1). 70 (3·5%) were classified as being at moderate risk of ACC and 1841 (91·3%) at low risk (negative predictive value 99·7%, 99·4–100·0). Interpretation An unenhanced CT tumour attenuation cutoff of 20 HU should replace that of 10 HU for exclusion of ACC. A triple test strategy of tumour diameter, imaging characteristics, and urine steroid metabolomics improves detection of ACC, which could shorten time to surgery for patients with ACC and help to avoid unnecessary surgery in patients with benign tumours. Funding European Commission, UK Medical Research Council, Wellcome Trust, and UK National ...
Objective: Although the succinate dehydrogenase (SDH)-related tumor spectrum has been recently expanded, there are only rare reports of non-pheochromocytoma/paraganglioma tumors in SDHx-mutated patients. Therefore, questions still remain unresolved concerning the aforementioned tumors with regard to their pathogenesis, clinicopathological phenotype, and even causal relatedness to SDHx mutations. Absence of SDHB expression in tumors derived from tissues susceptible to SDH deficiency is not fully elucidated. Design and methods: Three unrelated SDHD patients, two with pituitary adenoma (PA) and one with papillary thyroid carcinoma (PTC), and three SDHB patients affected by renal cell carcinomas (RCCs) were identified from four European centers. SDHA/SDHB immunohistochemistry (IHC), SDHx mutation analysis, and loss of heterozygosity analysis of the involved SDHx gene were performed on all tumors. A cohort of 348 tumors of unknown SDHx mutational status, including renal tumors, PTCs, PAs, neuroblastic tumors, seminomas, and adenomatoid tumors, was investigated by SDHB IHC. Printed in Great BritainPublished by Bioscientifica Ltd.Conclusions: These findings strengthen the etiological association of SDHx genes with pituitary neoplasia and provide evidence against a link between PTC and SDHx mutations. Somatic deletions seem to constitute the second hit in SDHB-related renal neoplasia, while SDHx alterations do not appear to be primary drivers in sporadic tumorigenesis from tissues affected by SDH deficiency.
The tricarboxylic acid (TCA) cycle enzyme succinate dehydrogenase (SDH) is a heterotetramer protein complex consisting of four subunits encoded by nuclear genes. These include SDHA and SDHB, which form the catalytic domain, and SDHC and SDHD, which anchor the complex to the inner mitochondrial membrane. 1 The assembly factors, SDHAF1 and SDHAF2, ensure both structural and functional integrity of the complex. 2,3 SDH, also called mitochondrial complex II, is the only enzyme involved in both the electron transport chain and the TCA cycle, where it catalyzes the oxidation of succinate to fumarate. 1 The TCA cycle is central to the metabolism of sugars, lipids, and amino acids and is a major source of adenosine triphosphate in cells. In addition, the cycle also seems to be involved in tumorigenesis; enzymes of the TCA cycle are involved in the pathogenesis of several tumor types. SDH mutations have been involved in the etiopathogeny of pheochromocytomas (PCCs), paragangliomas (PGLs), gastrointestinal stromal tumors (GISTs), renal-cell carcinomas (RCCs), and pituitary adenomas (PAs). 1,2,[4][5][6][7][8][9] In addition, mutations in fumarate hydratase (FH), another member of the TCA cycle and which catalyzes the hydration of fumarate to malate, predispose to tumor formation, including RCCs, cutaneous and uterine leiomyomas, and PCCs/PGLs. 10,11 Finally, isocitrate dehydrogenase (IDH), which catalyzes the oxidative decarboxylation of isocitrate, is frequently mutated in specific types of cartilaginous tumors, hematological malignancies, and gliomas. 12-14 The currently known mechanisms underlying tumorigenesis linked to defects in the TCA cycle are well reviewed. 15,16 Defects in the SDH, FH, and IDH genes inhibit prolyl hydroxylases, leading to decreased hydroxylation of hypoxia-inducible factor-α. This results in activation of the hypoxia pathway, which supports tumor formation by activating angiogenesis, glucose metabolism, cell motility, and cell survival. Furthermore, defects in these enzymes lead to epigenetic alterations through an accumulation of oncometabolites inhibiting α-ketoglutarate-dependent dioxygenases, which are involved in DNA and histone demethylation. In addition to SDH-associated tumorigenesis, constitutional complex II deficiencies caused by SDHA, SDHB, SDHD, and SDHAF1 mutations may also lead to Leigh syndrome, infantile leukodystrophies, and cardiomyopathy. 3,[17][18][19] In the current review, our aim is to report all currently known SDH mutations and define their nature and spectrum in SDHrelated tumors, including PCCs/PGLs, GISTs, RCCs, and PAs, as well as in other unusual tumors arising in SDH mutation carriers. We performed bioinformatics analysis using SIFT, Polyphen2, and Mutation Assessor and compared the results with those of SDHA/SDHB immunohistochemistry (IHC) to predict the functional impact of nonsynonymous mutations. Finally, we explored and report here the nature of the second hit in all tumors arising in the SDH deficiency setting. The tricarboxylic acid, or Krebs, cycle is cent...
Tumor DNA methylation emerges as an independent prognostic factor in ACC. MS-MLPA is readily compatible with clinical routine and should enhance our ability for prognostication and precision medicine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.