Comprehensive genomic analysis of adrenocortical carcinoma reveals genetic profiles associated with patient survival.

BACKGROUND: Adrenocortical carcinoma (ACC) is one of the most lethal endocrine malignancies and there is a lack of clinically useful markers for prognosis and patient stratification. Therefore our aim was to identify clinical and genetic markers that predict outcome in patients with ACC. METHODS: Clinical and genetic data from a total of 162 patients with ACC were analyzed by combining an independent cohort consisting of tumors from Yale School of Medicine, Karolinska Institutet, and Düsseldorf University (YKD) with two public databases [The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO)]. We used a novel bioinformatical pipeline combining differential expression and messenger RNA (mRNA)- and DNA-dependent survival. Data included reanalysis of previously conducted whole-exome sequencing (WES) for the YKD cohort, WES and RNA data for the TCGA cohort, and RNA data for the GEO cohort. RESULTS: We identified 3903 significant differentially expressed genes when comparing ACC and adrenocortical adenoma, and the mRNA expression levels of 461/3903 genes significantly impacted survival. Subsequent analysis revealed 45 of these genes to be mutated in patients with significantly worse survival. The relationship was significant even after adjusting for stage and age. Protein-protein interaction showed previously unexplored interactions among many of the 45 proteins, including the cancer-related proteins DNA polymerase delta 1 (POLD1), aurora kinase A (AURKA), and kinesin family member 23 (KIF23). Furthermore 14 of the proteins had significant interactions with TP53 which is the most frequently mutated gene in the germline of patients with ACC. CONCLUSIONS: Using a multiparameter approach, we identified 45 genes that significantly influenced survival. Notably, many of these genes have protein interactions not previously implicated in ACC. These findings may lay the foundation for improved prognostication and future targeted therapies.

Single-nuclei transcriptomes from human adrenal gland reveal distinct cellular identities of low and high-risk neuroblastoma tumors.

Childhood neuroblastoma has a remarkable variability in outcome. Age at diagnosis is one of the most important prognostic factors, with children less than 1 year old having favorable outcomes. Here we study single-cell and single-nuclei transcriptomes of neuroblastoma with different clinical risk groups and stages, including healthy adrenal gland. We compare tumor cell populations with embryonic mouse sympatho-adrenal derivatives, and post-natal human adrenal gland. We provide evidence that low and high-risk neuroblastoma have different cell identities, representing two disease entities. Low-risk neuroblastoma presents a transcriptome that resembles sympatho- and chromaffin cells, whereas malignant cells enriched in high-risk neuroblastoma resembles a subtype of TRKB+ cholinergic progenitor population identified in human post-natal gland. Analyses of these populations reveal different gene expression programs for worst and better survival in correlation with age at diagnosis. Our findings reveal two cellular identities and a composition of human neuroblastoma tumors reflecting clinical heterogeneity and outcome.

Impact of immunohistochemistry on the diagnosis and management of primary aldosteronism: An important tool for improved patient follow-up.

BACKGROUND AND AIMS: Primary aldosteronism is a common cause of secondary hypertension. Primary aldosteronism is caused by an aldosterone-producing adenoma or bilateral hyperplasia that in some cases is asymmetrical with one adrenal dominating aldosterone secretion. Most patients with aldosterone-producing adenoma are biochemically cured by unilateral adrenalectomy, but patients with bilateral hyperplasia have a significant risk of residual or recurrent disease. Here, immunohistochemistry of CYP11B1 and B2 was used to investigate whether these markers could aid in the diagnostic workup of primary aldosteronism patients. MATERIALS AND METHODS: A total of 39 patients with primary aldosteronism who underwent unilateral adrenalectomy for a presumed adenoma during 2013-2016 were included. Immunohistochemistry using monoclonal antibodies identifying the enzymes CYP11B1 and B2 was part of routine histopathological workup in 6 cases; in 33 cases, it was applied retrospectively. The hyperplasia diagnosis was suggested when there was no dominating nodule but immunoreactivity for CYP11B2 was seen in several nodules, which were also seen on routine sections. To distinguish between adenoma and hyperplasia, a ratio between the largest and second largest CYP11B2-positive nodules was calculated. RESULTS: In all, 22 patients had an aldosterone-producing adenoma, while 13 patients were judged to have hyperplasia. In four cases, a final diagnosis could not be established, thus these were judged equivocal. Among the 33 cases investigated retrospectively, the primary histopathological diagnosis was altered from hyperplasia to aldosterone-producing adenoma in 9 cases (27%) after immunohistochemistry, and the immunohistochemically rectified adenoma group displayed improved clinical cure rates compared to the routine H&E-diagnosed cohort. Moreover, the B2 ratio was significantly higher in adenoma than in hyperplasia and equivocal cases. CONCLUSION: Immunohistochemistry detecting CYP11B1 and B2 expression is of great help in establishing a final histopathological diagnosis in patients with primary aldosteronism. This procedure should be part of the histopathological routine in all operated primary aldosteronism patients.

A Clinical Overview of Telomerase-Associated Aberrancies in Follicular Thyroid Tumors as Diagnostic and Prognostic Markers: Tert Alert!

BACKGROUND AND AIMS: Endocrine surgeons and pathologists alike are well aware of the diagnostic predicament that follicular thyroid tumors impose in the clinical setting, best exemplified by the current inability to preoperatively assess the malignant potential of each individual lesion. As the proper recognition of a follicular thyroid carcinoma lies in the histopathological identification of invasive behavior, preoperative cytology alone is not yet sufficient to identify malignant tumors eligible for a total thyroidectomy upfront. Numerous auxiliary markers have been proposed as discriminating markers between follicular thyroid carcinomas and follicular thyroid adenomas, although many have proven suboptimal in terms of sensitivity, specificity, or overall clinical practicality. Of late, recurrent promoter mutations in the telomerase reverse transcriptase gene have been intimately coupled to subsets of well-differentiated thyroid cancer specimen with aggressive clinical characteristics as well as less differentiated forms of thyroid cancer with exceedingly poor prognosis. The mutations are thought to enhance the telomerase reverse transcriptase gene expressional output and cause immortalization through telomerase-associated mechanisms. MATERIALS AND METHODS: In this review, the current value of telomerase reverse transcriptase promoter mutations is detailed from a clinical angle-as well as the possible future application of additional telomerase reverse transcriptase gene aberrations as adjunct markers for the proper recognition of malignant potential. RESULTS: Telomerase reverse transcriptase promoter mutations are found in subsets of follicular thyroid carcinomas and follicular tumors of uncertain malignant potential while exceedingly rare in recurrence-free follicular thyroid adenomas. Collectively, these aberrancies are suggested as possible diagnostic and prognostic discriminators of follicular thyroid tumors. CONCLUSIONS: Telomerase reverse transcriptase gene analyses greatly facilitate the clinical assessment of follicular thyroid tumors, and pinpoints cases at risk of future recurrences. High-volume, tertiary thyroid centers are therefore recommended to implement the mutational screening in clinical routine.

Absence of the BRAF V600E mutation in pheochromocytoma.

PURPOSE: Pheochromocytomas (PCCs) are rare endocrine tumors originating from the adrenal medulla. These tumors display a highly heterogeneous mutation profile, and a substantial part of the causative genetic events remains to be explained. Recent studies have reported presence of the activating BRAF V600E mutation in PCC, suggesting a role for BRAF activation in tumor development. This study sought to further investigate the occurrence of the BRAF V600E mutation in these tumors. METHODS: A cohort of 110 PCCs was screened for the BRAF V600E mutation using direct Sanger sequencing. RESULTS: All cases investigated displayed wild-type sequences at nucleotide 1799 in the BRAF gene. CONCLUSIONS: Taken together with all previously screened tumors up to date, only 1 BRAF V600E mutation has been found among 361 PCCs. These findings imply that the BRAF V600E mutation is a rare event in pheochromocytoma.

Parafibromin immunoreactivity: its use as an additional diagnostic marker for parathyroid tumor classification.

Parafibromin is a protein product derived from the hyperparathyroidism 2(HRPT2) tumor suppressor geneand its inactivation has been coupled to familial and sporadic forms of parathyroid malignancy. In this study, we have conducted immunohistochemistry on 33 parathyroid carcinomas (22 unequivocal and 11 equivocal) using four parafibromin antibodies directed to different parts of the protein. Furthermore, for a fraction of cases, the immunohistochemical results were compared with known HRPT2 mutational status. Our findings show that 68% (15 out of 22) of the unequivocal carcinomas exhibited reduced expression of parafibromin while the 25 sporadic adenomas used as controls were entirely positive for parafibromin expression. Additionally, three out of the six carcinomas with known HRPT2 mutations showed reduced expression of parafibromin. Using all four antibodies, comparable results were obtained on the cellular level in individual tumors suggesting that there exists no epitope of choice in parafibromin immunohistochemistry. The results agree with the demonstration of a approximately 60 kDa product preferentially in the nuclear fraction by western blot analysis. We conclude that parafibromin immunohistochemistry could be used as an additional marker for parathyroid tumor classification, where positive samples have low risk of malignancy, whereas samples with reduced expression could be either carcinomas or rare cases of adenomas likely carrying an HRPT2 mutation.