Browse

You are looking at 121 - 130 of 2,347 items for

  • All content x
Clear All
Free access

Neil A Bhowmick, Jillian Oft, Tanya Dorff, Sumanta Pal, Neeraj Agarwal, Robert A Figlin, Edwin M Posadas, Stephen J Freedland, and Jun Gong

The current pandemic (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health challenge with active development of antiviral drugs and vaccines seeking to reduce its significant disease burden. Early reports have confirmed that transmembrane serine protease 2 (TMPRSS2) and angiotensin converting enzyme 2 (ACE2) are critical targets of SARS-CoV-2 that facilitate viral entry into host cells. TMPRSS2 and ACE2 are expressed in multiple human tissues beyond the lung including the testes where predisposition to SARS-CoV-2 infection may exist. TMPRSS2 is an androgen-responsive gene and its fusion represents one of the most frequent alterations in prostate cancer. Androgen suppression by androgen deprivation therapy and androgen receptor signaling inhibitors form the foundation of prostate cancer treatment. In this review, we highlight the growing evidence in support of androgen regulation of TMPRSS2 and ACE2 and the potential clinical implications of using androgen suppression to downregulate TMPRSS2 to target SARS-CoV-2. We also discuss the future directions and controversies that need to be addressed in order to establish the viability of targeting TMPRSS2 and/or ACE2 through androgen signaling regulation for COVID-19 treatment, particularly its relevance in the context of prostate cancer management.

Restricted access

Douglas Wiseman, James D McDonald, Dhaval Patel, Electron Kebebew, Karel Pacak, and Naris Nilubol

Postoperative hypotension frequently occurs after resection of pheochromocytoma and/or paraganglioma (PPGLs). Epidural anesthesia (EA) is often used for pain control in open resection of these tumors; one of its side effects is hypotension. Our aim is to determine if EA is associated with an increased risk of postoperative hypotension after open resection of PPGLs. We conducted a retrospective review of patients who underwent open resection of PPGLs at the National Institutes of Health from 2004 to 2019. Clinical and perioperative parameters were analyzed by the use of EA. The primary endpoint was postoperative hypotension. Ninety-seven patients (46 female and 51 male; mean age, 38.5 years) underwent open resection of PPGLs and 69 (71.1%) received EA. Patients with EA had a higher rate beta-blocker use (79.7% vs 57.1%, P = 0.041), metastasis (69.6% vs 39.3%, P = 0.011), and were more frequently hypotensive after surgery (58.8% vs 25.0%, P = 0.003) compared to those without EA. Patients with postoperative hypotension had higher plasma normetanephrines than those without (7.3 fold vs 4.1 fold above the upper limit of normal, P = 0.018). Independent factors associated with postoperative hypotension include the use of beta-blockers (HR = 3.35 (95% CI: 1.16–9.67), P = 0.026) and EA (HR = 3.49 (95% CI: 1.25–9.76), P = 0.017). Data from this retrospective study suggest that, in patients with open resection of PPGLs, EA is an independent risk factor for early postoperative hypotension. Special caution is required in patients on beta-blockade. A prospective evaluation with standardized protocols for the use of EA and management of hemodynamic variability is necessary.

Open access

Andreas M Hoff, Sigrid M Kraggerud, Sharmini Alagaratnam, Kaja C G Berg, Bjarne Johannessen, Maren Høland, Gro Nilsen, Ole C Lingjærde, Peter W Andrews, Ragnhild A Lothe, and Rolf I Skotheim

Testicular germ cell tumours (TGCTs) appear as different histological subtypes or mixtures of these. They show similar, multiple DNA copy number changes, where gain of 12p is pathognomonic. However, few high-resolution analyses have been performed and focal DNA copy number changes with corresponding candidate target genes remain poorly described for individual subtypes. We present the first high-resolution DNA copy number aberration (CNA) analysis on the subtype embryonal carcinomas (ECs), including 13 primary ECs and 5 EC cell lines. We identified recurrent gains and losses and allele-specific CNAs. Within these regions, we nominate 30 genes that may be of interest to the EC subtype. By in silico analysis of data from 150 TGCTs from The Cancer Genome Atlas (TCGA), we further investigated CNAs, RNA expression, somatic mutations and fusion transcripts of these genes. Among primary ECs, ploidy ranged between 2.3 and 5.0, and the most common aberrations were DNA copy number gains at chromosome (arm) 7, 8, 12p, and 17, losses at 4, 10, 11, and 18, replicating known TGCT genome characteristics. Gain of whole or parts of 12p was found in all samples, including a highly amplified 100 kbp segment at 12p13.31, containing SLC2A3. Gain at 7p21, encompassing ETV1, was the second most frequent aberration. In conclusion, we present novel CNAs and the genes located within these regions, where the copy number gain of SLC2A3 and ETV1 are of interest, and which copy number levels also correlate with expression in TGCTs.

Restricted access

Yulong Li, Jianhua Zhang, Poorni R Adikaram, James Welch, Bin Guan, Lee S Weinstein, Haobin Chen, and William F Simonds

Mutation of the CDC73 gene, which encodes parafibromin, has been linked with parathyroid cancer. However, no correlation between genotypes of germline CDC73 mutations and the risk of parathyroid cancer has been known. In this study, subjects with germline CDC73 mutations were identified from the participants of two clinical protocols at National Institutes of Health (Discovery Cohort) and from the literature (Validation Cohort). The relative risk of developing parathyroid cancer was analyzed as a function of CDC73 genotype, and the impact of representative mutations on structure of parafibromin was compared between genotype groups. A total of 419 subjects, 68 in Discovery Cohort and 351 in Validation Cohort, were included. In both cohorts, percentages of CDC73 germline mutations that predicted significant conformational disruption or loss of expression of parafibromin (referred as ‘high-impact mutations’) were significantly higher among the subjects with parathyroid cancers compared to all other subjects. The Kaplan–Meier analysis showed that high-impact mutations were associated with a 6.6-fold higher risk of parathyroid carcinoma compared to low-impact mutations, despite a similar risk of developing primary hyperparathyroidism between two groups. Disruption of the C-terminal domain (CTD) of parafibromin is directly involved in predisposition to parathyroid carcinoma, since only the mutations impacting this domain were associated with an increased risk of parathyroid carcinoma. Structural analysis revealed that a conserved surface structure in the CTD is universally disrupted by the mutations affecting this domain. In conclusion, high-impact germline CDC73 mutations were found to increase risk of parathyroid carcinoma by disrupting the CTD of parafibromin.

Free access

Tim J Takkenkamp, Mathilde Jalving, Frederik J H Hoogwater, and Annemiek M E Walenkamp

Immunotherapy in the form of immune checkpoint inhibitors (ICIs) has transformed the treatment landscape in numerous types of advanced cancer. However, the majority of patients do not benefit from this treatment modality. Although data are scarce, in general, patients with low-grade neuroendocrine tumours (NETs) do not benefit from treatment with ICIs in contrast to patients with neuroendocrine carcinoma, in which a small subgroup of patients may benefit. Low- and intermediate-grade NETs predominantly lack factors associated with response to ICIs treatment, like immune cell infiltration, and have an immunosuppressive tumour metabolism and microenvironment. In addition, because of its potential influence on the response to ICIs, major interest has been shown in the tryptophan-degrading enzymes indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO). These enzymes work along the kynurenine pathway that deplete tryptophan in the tumour microenvironment. IDO and TDO are especially of interest in NETs since some tumours produce serotonin but the majority do not, which potentially deplete the precursor tryptophan. In this review, we summarize the current knowledge on the immune tumour microenvironment of neuroendocrine tumours and implications for treatment with immune checkpoint inhibitors. We also discuss (targetable) factors in the NET tumour microenvironment that potentially modulate the anti-cancer immune response.

Free access

Jack Junjie Chan, Yirong Sim, Samuel Guan Wei Ow, Joline Si Jing Lim, Grace Kusumawidjaja, Qingyuan Zhuang, Ru Xin Wong, Fuh Yong Wong, Veronique Kiak Mien Tan, and Tira Jing Ying Tan

The ensuing COVID-19 pandemic poses unprecedented and daunting challenges to the routine delivery of oncological and supportive care to patients with breast cancer. Considerations include the infective risk of patients who are inherently immunosuppressed from their malignancy and therapies, long-term oncological outcomes from the treatment decisions undertaken during this extraordinary period, and diverted healthcare resources to support a coordinated whole-of-society outbreak response. In this review, we chronicle the repercussions of the COVID-19 outbreak on breast cancer management in Singapore and describe our approach to triaging and prioritising care of breast tumours. We further propose adaptations to established clinical processes and practices across the different specialties involved in breast oncology, with references to the relevant evidence base or expert consensus guidelines. These recommendations have been developed within the unique context of Singapore’s public healthcare sector. They can serve as a resource to guide breast cancer management for future contingencies in this city-state, while certain elements therein may be extrapolatable to other medical systems during this global public health emergency.

Free access

Derek Raghavan, Antoinette R Tan, E Shannon Story, Earle F Burgess, Laura Musselwhite, Edward S Kim, and Peter E Clark

Substantial management changes in endocrine-related malignancies have been required as a response to the COVID-19 pandemic, including a draconian reduction in the screening of asymptomatic subjects, delay in planned surgery and radiotherapy for primary tumors deemed to be indolent, and dose reductions and/or delays in initiation of some systemic therapies. An added key factor has been a patient-initiated delay in the presentation because of the fear of viral infection. Patterns of clinical consultation have changed, including a greater level of virtual visits, physical spacing, masking, staffing changes to ensure a COVID-free population and significant changes in patterns of family involvement. While this has occurred to improve safety from COVID-19 infection, the implications for cancer outcomes have not yet been defined. Based on prior epidemics and financial recessions, it is likely that delayed presentation and treatment of high-grade malignancy will be associated with worse cancer outcomes. Cancer patients are also at increased risk from COVID-19 infection compared to the general population. Pandemic management strategies for patients with tumors of breast, prostate, thyroid, parathyroid and adrenal gland are reviewed.

Open access

Xiyuan Zhang, Fabia de Oliveira Andrade, Hansheng Zhang, Idalia Cruz, Robert Clarke, Pankaj Gaur, Vivek Verma, and Leena Hilakivi-Clarke

Over 50% of women at a childbearing age in the United States are overweight or obese, and this can adversely affect their offspring. We studied if maternal obesity-inducing high fat diet (HFD) not only increases offspring’s mammary cancer risk but also impairs response to antiestrogen tamoxifen. Female rat offspring of HFD and control diet-fed dams, in which estrogen receptor-positive (ER+) mammary tumors were induced with the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA), exhibited similar initial responses to antiestrogen tamoxifen. However, after tamoxifen therapy was completed, almost all (91%) tumors recurred in HFD offspring, compared with only 29% in control offspring. The increase in local mammary tumor recurrence in HFD offspring was linked to an increase in the markers of immunosuppression (Il17f, Tgfβ1, VEGFR2) in the tumor microenvironment (TME). Protein and mRNA levels of the major histocompatibility complex II (MHC-II), but not MHC-I, were reduced in the recurring DMBA tumors of HFD offspring. Further, infiltration of CD8+ effector T cells and granzyme B+ (GZMB+) cells were lower in their recurring tumors. To determine if maternal HFD can pre-program similar changes in the TME of allografted E0771 mammary tumors in offspring of syngeneic mice, flow cytometry analysis was performed. E0771 mammary tumor growth was significantly accelerated in the HFD offspring, and a reduction in the numbers of GZMB and non-significant reduction of interferon γ (IFNγ) secreting CD8+ T cells in the TME was seen. Thus, consumption of a HFD during pregnancy increases susceptibility of the female rat and mouse offspring to tumor immune suppression and mammary tumor growth and recurrence.

Free access

Simona Grozinsky-Glasberg, Kate E Lines, Shani Avniel-Polak, Chas Bountra, and Rajesh V Thakker

Neuroendocrine neoplasms (NENs) occur usually as sporadic tumours; however, rarely, they may arise in the context of a hereditary syndrome, such as multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disorder characterised by the combined development of pancreatic NENs (pNENs) together with parathyroid and anterior pituitary tumours. The therapeutic decision for sporadic pNENs patients is multi-disciplinary and complex: based on the grade and stage of the tumor, various options (and their combinations) are considered, such as surgical excision (either curative or for debulking aims), biological drugs (somatostatin analogues), targeted therapies (mTOR inhibitors or tyrosine kinases (TK)/receptors inhibitors), peptide receptor radioligand therapy (PRRT), chemotherapy, and liver-directed therapies. However, treatment of MEN1-related NENs’ patients is even more challenging, as these tumours are usually multifocal with co-existing foci of heterogeneous biology and malignant potential, rendering them more resistant to the conventional therapies used in their sporadic counterparts, and therefore associated with a poorer prognosis. Moreover, clinical data using standard therapeutic options in MEN1-related NENs are scarce. Recent preclinical studies have identified potentially new targeted therapeutic options for treating MEN1-associated NENs, such as epigenetic modulators, Wnt pathway-targeting β-catenin antagonists, Ras signalling modulators, Akt/mTOR signalling modulators, novel somatostatin receptors analogues, anti-angiogenic drugs, as well as MEN1 gene replacement therapy. The present review aims to summarize these novel therapeutic opportunities for NENs developing in the context of MEN1 syndrome, with an emphasis on pancreatic NENs, as they are the most frequent ones studied in MEN1-NENs models to date; moreover, due to the recent shifting nomenclature of ‘pituitary adenomas’ to ‘pituitary neuroendocrine neoplasms’, relevant data on MEN1-pituitary tumours, when appropriate, are briefly described.