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Dimitra A Vassiliadi and Stylianos Tsagarakis

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a highly heterogeneous entity. The incidental identification of an increasing number of cases has shifted its clinical expression from the rarely encountered severe forms, regarding both cortisol excess and adrenal enlargement, to mild forms of asymptomatic or oligosymptomatic cases with less impressive imaging phenotypes. Activation of cAMP/PKA pathway, either due to alterations of the different downstream signaling pathways or through aberrantly expressed G-protein-coupled receptors, relates to both cortisol secretion and adrenal growth. Germline ARMC5 mutations are a frequent genetic defect. The diagnostic approach consists of both imaging and hormonal characterization. Imaging characterization should be done separately for each lesion. Endocrine evaluation in cases with clinically overt Cushing’s syndrome (CS) is similar to that applied for all forms of CS. In incidentally detected PBMAH, hormonal evaluation includes testing for primary aldosteronism, pheochromocytoma and evaluation for autonomous cortisol secretion, using the 1 mg overnight dexamethasone suppression test. Midnight cortisol or 24-h urinary free cortisol may aid in establishing the degree of cortisol excess. In patients with hypercortisolism, ACTH levels should be measured in order to establish ACTH independency. At variance with other forms of CS, PBMAH may be characterized by a distinct pattern of inefficient steroidogenesis. The appropriate management of PBMAH remains controversial. Bilateral adrenalectomy results in lifetime steroid dependency and is better reserved only for patients with severe CS. Unilateral adrenalectomy might be considered in selected patients. In cases where the regulation of cortisol secretion is mediated by aberrant receptors there is some potential for medical therapy.

Free access

Fabian Pitoia and Fernando Jerkovich

The stratification of patients with differentiated thyroid cancer based on their initial risk of recurrence, according to specific clinical, histopathological and perioperative data, is an important starting point for tailoring the follow-up during the first 1–2 years after initial therapy (surgery with or without radioiodine ablation). However, risk of recurrence re-stratification based on new clinical data that becomes available after considering the response to treatment (dynamic risk assessment) provides a more accurate prediction of the status at final follow-up and a more individualized approach. In this review, we summarized the available data regarding dynamic risk of recurrence and the suggested management of differentiated thyroid cancer patients according to the response to treatment. The use of this strategy is crucial to avoid overtreatment and intensive follow-up of the vast majority of patients who will have a very good prognosis and, on the other hand, focus therapeutic efforts on those patients who will have a worse prognosis. In the future, molecular biology analysis of the tumors and well-designed prospective studies will probably refine the risk of recurrence prediction.

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Cathy B Moelans, Joep de Ligt, Petra van der Groep, Pjotr Prins, Nicolle J M Besselink, Marlous Hoogstraat, Natalie D ter Hoeve, Miangela M Lacle, Robert Kornegoor, Carmen C van der Pol, Wendy W J de Leng, Ellis Barbé, Bert van der Vegt, John Martens, Peter Bult, Vincent T H B M Smit, Marco J Koudijs, Isaac J Nijman, Emile E Voest, Pier Selenica, Britta Weigelt, Jorge S Reis-Filho, Elsken van der Wall, Edwin Cuppen and Paul J van Diest

Male breast cancer (MBC) is extremely rare and accounts for less than 1% of all breast malignancies. Therefore, clinical management of MBC is currently guided by research on the disease in females. In this study, DNA obtained from 45 formalin-fixed paraffin-embedded (FFPE) MBCs with and 90 MBCs (52 FFPE and 38 fresh-frozen) without matched normal tissues was subjected to massively parallel sequencing targeting all exons of 1943 cancer-related genes. The landscape of mutations and copy number alterations was compared to that of publicly available estrogen receptor (ER)-positive female breast cancers (smFBCs) and correlated to prognosis. From the 135 MBCs, 90% showed ductal histology, 96% were ER-positive, 66% were progesterone receptor (PR)-positive, and 2% HER2-positive, resulting in 50, 46 and 4% luminal A-like, luminal B-like and basal-like cases, respectively. Five patients had Klinefelter syndrome (4%) and 11% of patients harbored pathogenic BRCA2 germline mutations. The genomic landscape of MBC to some extent recapitulated that of smFBC, with recurrent PIK3CA (36%) and GATA3 (15%) somatic mutations, and with 40% of the most frequently amplified genes overlapping between both sexes. TP53 (3%) somatic mutations were significantly less frequent in MBC compared to smFBC, whereas somatic mutations in genes regulating chromatin function and homologous recombination deficiency-related signatures were more prevalent. MDM2 amplifications were frequent (13%), correlated with protein overexpression (P = 0.001) and predicted poor outcome (P = 0.007). In conclusion, despite similarities in the genomic landscape between MBC and smFBC, MBC is a molecularly unique and heterogeneous disease requiring its own clinical trials and treatment guidelines.

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Ryan K Orosco, Timon Hussain, Julia E Noel, David C Chang, Chrysoula Dosiou, Erik Mittra, Vasu Divi and Lisa A Orloff

Radioactive iodine (RAI) is a key component in the treatment of differentiated thyroid cancer. RAI has been recommended more selectively in recent years as guidelines evolve to reflect risks and utility in certain patient subsets. In this study we sought to evaluate the survival impact of radioactive iodine in specific thyroid cancer subgroups. Nationwide retrospective cohort study of patients using the National Cancer Database (NCDB) from 2004 to 2012 and Surveillance, Epidemiology, and End Results (SEER) database from 1992 to 2009 examining patients with differentiated thyroid cancer treated with or without RAI. Primary outcomes included all-cause mortality (NCDB and SEER), and cancer-specific mortality (SEER). Cox multivariate survival analyses were applied to each dataset, and in 135 patient subgroups based on clinical and non-clinical parameters. A total of 199,371 NCDB and 77,187 SEER patients were identified. RAI was associated with improved all-cause mortality (NCDB: RAI hazard ratio (HR) 0.55, P < 0.001; SEER: HR 0.64, P < 0.001); and cancer-specific mortality (SEER: HR 0.82, P = 0.029). Iodine therapy showed varied efficacy within each subgroup. Patients with high-risk disease experienced the greatest benefit in all-cause mortality, followed by intermediate-risk, then low-risk subgroups. Regarding cancer-specific mortality, radioactive iodine therapy was protective in high-risk patients, but did not achieve statistical significance in most intermediate-risk subgroups. Low-risk T1a subgroups demonstrated an increased likelihood of cancer-specific mortality with iodine therapy. The efficacy of RAI in patients with differentiated thyroid cancer varies by disease severity. A negative cancer-specific survival association was identified in patients with T1a disease. These findings warrant further evaluation with prospective studies.

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Adwitiya Kar, Yu Zhang, Betelehem W Yacob, Jordan Saeed, Kenneth D Tompkins, Stacey M Bagby, Todd M Pitts, Hilary Somerset, Stephen Leong, Margaret E Wierman and Katja Kiseljak-Vassiliades

Adrenocortical carcinoma (ACC) is an aggressive orphan malignancy with less than 35% 5-year survival and 75% recurrence. Surgery remains the primary therapy and mitotane, an adrenolytic, is the only FDA-approved drug with wide-range toxicities and poor tolerability. There are no targeted agents available to date. For the last three decades, H295R cell line and its xenograft were the only available preclinical models. We recently developed two new ACC patient-derived xenograft mouse models and corresponding cell lines (CU-ACC1 and CU-ACC2) to advance research in the field. Here, we have utilized these novel models along with H295R cells to establish the mitotic PDZ-binding kinase (PBK) as a promising therapeutic target. PBK is overexpressed in ACC samples and correlates with poor survival. We show that PBK is regulated by FOXM1 and targeting PBK via shRNA decreased cell proliferation, clonogenicity and anchorage-independent growth in ACC cell lines. PBK silencing inhibited pAkt, pp38MAPK and pHistone H3 altering the cell cycle. Therapeutically, targeting PBK with the small-molecule inhibitor HITOPK032 phenocopied PBK-specific modulation of pAkt and pHistone H3, but also induced apoptosis via activation of JNK. Consistent with in vitro findings, treatment of CU-ACC1 PDXs with HITOPK032 significantly reduced tumor growth by 5-fold (P < 0.01). Treated tumor tissues demonstrated increased rates of apoptosis and JNK activation, with decreased pAkt and Histone H3 phosphorylation, consistent with effects observed in ACC cell lines. Together these studies elucidate the mechanism of PBK in ACC tumorigenesis and establish the potential therapeutic potential of HITOPK032 in ACC patients.

Open access

S Felder, H Jann, R Arsenic, T Denecke, V Prasad, B Knappe-Drzikova, S Maasberg, B Wiedenmann, M Pavel, A Pascher and U F Pape

Although gastric neuroendocrine neoplasias (gNEN) are an orphan disease, their incidence is rising. The heterogeneous clinical course powers the ongoing discussion of the most appropriate classification system and management. Prognostic relevance of proposed classifications was retrospectively analysed in 142 patients from a single tertiary referral centre. Baseline, management and survival data were acquired for statistical analyses. The distribution according to the clinicopathological typification was gNEN-1 (n = 86/60.6%), gNEN-2 (n = 7/4.9%), gNEN-3 (n = 24/16.9%) and gNEN-4 (n = 25/17.6%), while hypergastrinemia-associated gNEN-1 and -2 were all low-grade tumours (NET-G1/2), formerly termed sporadic gNEN-3 could be subdivided into gNEN-3 with grade 1 or 2 and gNEN-4 with grade 3 (NEC-G3). During follow-up 36 patients died (25%). The mean overall survival (OS) of all gNEN was 14.2 years. The OS differed statistically significant across all subgroups with either classification system. According to UICC 2017 TNM classification, OS differed for early and advanced stages, while WHO grading indicated poorer prognosis for NEC-G3. Cox regression analysis confirmed the independent prognostic validity of either classification system for survival. Particularly careful analysis of the clinical course of gNEN-1 (ECLomas, gastric carcinoids) confirmed their mostly benign, but recurrent and extremely slowly progressive behaviour with low risk of metastasis (7%) and an efficient long-term control by repetitive endoscopic procedures. Our study provides evidence for the validity of current classifications focusing on typing, grading and staging. These are crucial tools for risk stratification, especially to differentiate gNEN-1 as well as sporadic gNET and gNEC (gNEN-3 vs -4).

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Monia Zidane, Jean Baptiste Cazier, Sylvie Chevillard, Catherine Ory, Martin Schlumberger, Corinne Dupuy, Jean François Deleuze, Anne Boland, Nadia Haddy, Fabienne Lesueur and Florent de Vathaire

The first study establishing exposure to ionizing radiations (IR) as a risk factor for differentiated thyroid cancer (DTC) was published 70 years ago. Given that radiation exposure causes direct DNA damage, genetic alterations in the different DNA repair mechanisms are assumed to play an important role in long-term IR induced DNA damage prevention. Individual variations in DNA repair capacity may cause different reaction to damage made by IR exposure. The aim of this review is to recapitulate current knowledge about constitutional genetic polymorphisms found to be significatively associated with DTC occurring after IR exposure. Studies were screened online using electronic databases, only fully available articles, studies performed among irradiated population or taking radiation exposure as adjustment factors and showing significative results are included. Nine articles were identified. Ten variants in/near to genes in six biological pathways, namely thyroid activity regulations, generic transcription, RET signaling, ATM signaling and DNA repair pathways were found to be associated with radiation-related DTC in these studies. Only seven variants were found to be in interaction with IR exposure in DTC risk. Most of these variants are also associated to sporadic DTC and are not specific to IR related DTC. In the published studies, no data on children treated with radiotherapy is described. In conclusion, more studies carried out on larger cohorts or on case-control studies with well documented individual radiation dose estimations are needed to get a comprehensive picture of genetic susceptibility factors involved in radiation-related DTC.

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Fahmida Rasha, Latha Ramalingam, Lauren Gollahon, Rakhshanda Rahman, Shaikh Mizanoor Rahman, Kalhara Menikdiwela and Naima Moustaid-Moussa

Obesity is a complex disease and a global epidemic. It is a risk factor for other chronic diseases including breast cancer, especially in women after menopause. Diverse etiologies underlie the relationship between obesity and breast cancer. Adipose tissue is in part responsible for these interactions. In obesity, adipose tissue undergoes several metabolic dysregulations resulting in secretion of many proinflammatory cytokines, growth factors, and hormones which in turn, can promote tumor microenvironment (TME) formation and cancer progression within the breast tissue. Angiotensin II (Ang II) is a well-known hypertensive hormone produced systemically and locally by the renin-angiotensin system (RAS). Activation of this system in obesity is a potential contributor to local and systemic inflammation in breast adipose tissue. Ang II actions are primarily mediated through binding to its two receptors, type 1 (AT1R) and type 2 (AT2R). RAS inhibitors include angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB) which are currently prescribed as safe anti-hypertensive therapies. Recent studies have explored potential use of ACE-I and ARBs in breast cancer patients as anti-tumor agents. Therefore, it is vital to understand the role of RAS in breast cancer, and identify mechanisms of Ang II and RAS inhibitors in the TME and in obesity and breast cancer crosstalk. In this review, we performed a detailed analysis and discussed mechanisms of Ang II-AT1R interactions in breast cancer with emphasis on obesity-associated breast cancer. We further summarized recent in vitro, in vivo and human studies that used ACE-I/ARB interventions to improve breast cancer outcomes.

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Xuguang Zhu, Sunmi Park, Woo Kyung Lee and Sheue-yann Cheng

Anaplastic thyroid cancer (ATC) is an aggressive malignancy with limited treatment options. We explored novel treatment modalities by targeting epigenetic modifications using inhibitors of BET (e.g. BRD4) activity. We evaluated the efficacy in the treatment of ATC of a novel BET inhibitor, PLX51107 (PLX), currently in clinical trials for other solid tumors and hematologic malignancies, alone or combined with a MEK inhibitor, PD0325901(PD). To elucidate the effects of these inhibitors on growth of ATC, we treated ATC cells derived from patient tumors (THJ-11T and THJ-16T cells) and mouse xenograft tumors with inhibitors. We found PLX and PD inhibitors singly inhibited proliferation of both human ATC cells lines, but together exhibited stronger inhibition of proliferation. In mouse xenografts, the combination treatment almost totally blocked growth in xenograft tumors derived from both ATC cells. PD effectively attenuated MEK-ERK signaling, which was further enhanced by PLX in the combined treatment in cultured cells and tumors. Importantly, the combination of PLX and PD acted synergistically to suppress MYC transcription to increase p27 in decreasing tumor cell proliferation. PLX and PD cooperated to upregulate pro-apoptotic proteins to promote apoptosis. These two inhibitors converged to reduce the binding of BRD4 to the MYC promoter to suppress the MYC expression. These findings indicate that combined treatment of BET and MEK-ERK inhibitors was more effective to treat ATC than single targeted treatment. Synergistic suppression of MYC transcription via collaborative actions on chromatin modifications suggested that targeting epigenetic modifications could provide novel treatment opportunities for ATC.

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Moray J Campbell

The three-dimensional organization of the genome within the cell nucleus has come into sharp focus over the last decade. This has largely arisen because of the application of genomic approaches that have revealed numerous levels of genomic and chromatin interactions, including topologically associated domains (TADs). The current review examines how these domains were identified, are organized, how their boundaries arise and are regulated, and how genes within TADs are coordinately regulated. There are many examples of the disruption to TAD structure in cancer and the altered regulation, structure and function of TADs are discussed in the context of hormone responsive cancers, including breast, prostate and ovarian cancer. Finally, some aspects of the statistical insight and computational skills required to interrogate TAD organization are considered and future directions discussed.