Molecular targeted therapies in adrenal, pituitary and parathyroid malignancies

Circulating non-coding RNA biomarkers of endocrine tumours

Circulating non-coding RNA (ncRNA) molecules are being investigated as biomarkers of malignancy, prognosis and follow-up in several neoplasms, including endocrine tumours of the pituitary, parathyroid, pancreas and adrenal glands. Most of these tumours are classified as neuroendocrine neoplasms (comprised of neuroendocrine tumours and neuroendocrine carcinomas) and include tumours of variable aggressivity. We consider them together here in this Review owing to similarities in their clinical presentation, pathomechanism and genetic background. No preoperative biomarkers of malignancy are available for several forms of these endocrine tumours. Moreover, biomarkers are also needed for the follow-up of tumour progression (especially in hormonally inactive tumours), prognosis and treatment efficacy monitoring. Circulating blood-borne ncRNAs show promising utility as biomarkers. These ncRNAs, including microRNAs, long non-coding RNAs and circular RNAs, are involved in several aspects of gene expression regulation, and their stability and tissue-specific expression could make them ideal biomarkers. However, no circulating ncRNA biomarkers have yet been introduced into routine clinical practice, which is mostly owing to methodological and standardization problems. In this Review, following a brief synopsis of these endocrine tumours and the biology of ncRNAs, the major research findings, pathomechanisms and methodological questions are discussed along with an outlook for future studies.

Parathyroid carcinoma: lessons from a rare malignancy of head and neck-a case series

Parathyroid carcinoma (PC) is a very rare head-neck malignancy. Because the symptoms of parathyroid carcinoma are similar to those of benign causes of hyperparathyroidism, it may be not easy to detect it before surgery. The management of PC after initial surgery will be perplexing because of the adequacy of surgery. We wish to describe the difficulties encountered throughout treatment using a literature review. We conducted a retrospective analysis of individuals with parathyroid carcinoma who had treatment at our department between 2017 and 2022. We gathered data on the clinical profile, investigations, management of hypercalcemia, surgical techniques, histopathological features, adjuvant therapy, and outcomes. We treated three patients with parathyroid carcinoma: Two patients with inferior parathyroid carcinoma and one with superior parathyroid carcinoma. Generalized weakness and bony pain are the predominant symptoms. In all cases, the tumor was located using 99Tc MIBI / SPECT scintigraphy and Ultrasonography. Hemithyroidectomy and tumor excision were done as the surgery of choice. All are disease-free at the 12th-month follow-up. We suggested that parathyroid hormone testing be performed in all bony fibrous lesions to rule out hyperparathyroidism. PC is a likely diagnosis when there is noticeable throat swelling, elevated PTH levels greater than 400 IU/L, and serum calcium levels greater than 15 mg/dL.

Recent Therapeutic Advances in Pituitary Carcinoma

Pituitary carcinoma (PC) is a rare, aggressive malignancy that comprises 0.1-0.2% of all pituitary tumors. PC is defined anatomically as a pituitary tumor that metastasizes outside the primary intrasellar location as noncontiguous lesions in the central nervous system or as metastases to other organs. Similar to pituitary adenoma, PC originates from various cell types of the pituitary gland and can be functioning or nonfunctioning, with the former constituting the majority of the cases. Compression of intricate skull-based structures, excessive hormonal secretion, impaired pituitary function from therapy, and systemic metastases lead to debilitating symptoms and a poor survival outcome in most cases. PC frequently recurs despite multimodality treatments, including surgical resection, radiotherapy, and biochemical and cytotoxic treatments. There is an unmet need to better understand the pathogenesis and molecular characterization of PC to improve therapeutic strategies. As our understanding of the role of signaling pathways in the tumorigenesis of and malignant transformation of PC evolves, efforts have focused on targeted therapy. In addition, recent advances in the use of immune checkpoint inhibitors to treat various solid cancers have led to an interest in exploring the role of immunotherapy for the treatment of aggressive refractory pituitary tumors. Here, we review our current understanding of the pathogenesis, molecular characterization, and treatment of PC. Particular attention is given to emerging treatment options, including targeted therapy, immunotherapy, and peptide receptor radionuclide therapy.

Special Issue: Present and Future of Personalised Medicine for Endocrine Cancers

Major technological advances in genomics have made it possible to identify critical genetic alterations in cancer, rendering oncology well along the path to personalised cancer medicine [...].

Parathyroid carcinoma in a 13-year-old girl with a long-term survival

Background

Parathyroid carcinoma as a cause of primary hyperparathyroidism in children is extremely rare. We report a case of parathyroid carcinoma which occurred in a 13-year-old girl who survived for more than 45 years after the first operation.

Case presentation

A woman was admitted to our hospital for the treatment of recurrent parathyroid carcinoma in the neck. She had been diagnosed with primary hyperparathyroidism from a fibula fracture and underwent parathyroidectomy at 13 years old. She had no family history of multiple endocrine neoplasia or jaw tumor syndrome. Genetic testing was not performed, and the histopathological diagnosis of the tumor had been parathyroid adenoma at the time. At 22 years old, she showed hypercalcemia after a femur fracture. Pulmonary metastases of parathyroid carcinoma in the bilateral lungs were found and surgically removed. Regarding the clinical course, her diagnosis was corrected from parathyroid adenoma to parathyroid carcinoma. At 33 years old, re-resection of the lung metastases was performed. For 10 years, her serum calcium level stayed within the normal range. However, her serum calcium level and intact parathyroid hormone eventually began to increase. Two masses suspected of being parathyroid carcinoma recurrence were found in the neck when she was 57 years old. En bloc resection was performed. Pathologically, the tumors were diagnosed as parathyroid adenoma. The serum calcium level and intact parathyroid hormone did not decrease after the operation. A ^99mTc-methoxy-isobutyl-isonitrile- and ¹⁸F-fluorodeoxyglucose-negative, ¹¹C-methionine-positive tumor was detected at the right side of the trachea in the neck. The tumor was removed, along with the thyroid, muscle, and trachea that were involved. The pathological diagnosis was parathyroid carcinoma recurrence. The serum calcium level and intact parathyroid hormone decreased temporarily but had increased again 8 months later. Methionine-positive tumors were found at the right side of the trachea and suspected of being a recurrence. Denosumab reduced her serum calcium level, and radiation successfully suppressed the growth of the recurrent tumors.

Conclusion

We have reported a rare case of parathyroid carcinoma in a child who has survived for over 40 years. Positron emission tomography of ¹¹C-methionine was useful for detecting local recurrence. This patient’s long-term survival has been attributed to multimodality treatment including repeated surgery, medication, and radiation.

Genetics and imaging of pheochromocytomas and paragangliomas: current update

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare, heterogeneous neuroendocrine neoplasms of the autonomous nervous system of chromaffin cell origin that may arise within the adrenal medulla (PCCs) or the sympathetic and parasympathetic paraganglia (PGLs). Currently referred to by the umbrella term pheochromocytomas-paragangliomas (PPGLs), these distinct tumors are characterized by specific histopathology as well as biological and clinical profiles. PPGLs may occur as part of hereditary syndromes (40% of cases) or as sporadic tumors. Currently, there are 12 different hereditary syndromes with characteristic genetic abnormalities, at least 15 well-characterized driver genes and distinct tumor metabolic pathways. Based on the Cancer Genome Atlas (TCGA) taxonomic schemata, PPGLs have been classified into three main clusters of specific genetic mutations and tumor pathways with clinical, biochemical, and prognostic implications. Imaging plays a pivotal role in the initial diagnosis, tumor characterization, evaluation of treatment response, and long-term surveillance. While MDCT and MRI help in the anatomic localization, SPECT, and PET using different radiotracers are crucial in the functional assessment of these tumors. Surgery, chemotherapy, and radiotherapy are currently available treatment options for PPGLs; antiangiogenic drugs are also being used in treating metastatic disease. Evolving knowledge regarding the different genetic abnormalities involved in the pathogenesis of PPGLs has identified potential therapeutic targets that may be utilized in the discovery of novel drugs.

Clinical genetic testing in endocrinology: Current concepts and contemporary challenges

Recent advances in DNA sequencing technology have led to an unprecedented period of disease-gene discovery offering many new opportunities for genetic testing in the clinical setting. Endocrinology has seen a rapid expansion in the taxonomy of monogenic disorders, which can be detected by an expanding portfolio of genetic tests in both diagnostic and predictive settings. Successful testing relies on many factors including the ability to identify those at increased risk of genetic disease in the busy clinic as well as a working knowledge of the various testing platforms and their limitations. The clinical utility of a given test is dependent upon many factors, which include the reliability of the genetic testing platform, the accuracy of the test result interpretation and knowledge of disease penetrance and expression. The increasing adoption of "high-content" genetic testing based on next-generation sequencing (NGS) to diagnose hereditary endocrine disorders brings a number of challenges including the potential for uncertain test results and/or genetic findings unrelated to the indication for testing. Therefore, it is increasingly important that the clinician is aware of the current evolution in genetic testing, and understands the different settings in which it may be employed. This review provides an overview of the genetic testing workflow, focusing on each of the major components required for successful testing in adult and paediatric endocrine settings. In addition, the challenges of variant interpretation are highlighted, as are issues related to informed consent, prenatal diagnosis and predictive testing. Finally, the future directions of genetic testing relevant to endocrinology are discussed.

Gonadotrophin-releasing hormone agonist-induced pituitary adenoma apoplexy and casual finding of a parathyroid carcinoma: A case report and review of literature

BACKGROUND

Pituitary apoplexy represents one of the most serious, life threatening endocrine emergencies that requires immediate management. Gonadotropin-releasing hormone agonist (GnRHa) can induce pituitary apoplexy in those patients who have insidious pituitary adenoma coincidentally.

CASE SUMMARY

A 46-year-old woman, with a history of hypertension and menorrhagia was transferred to our hospital from a secondary care hospital after complaints of headache and vomiting, with loss of consciousness 5 min after an injection of GnRHa. The drug was prescribed by her gynecologist due to the presence of uterine myomas. The clinical neurological examination revealed right cranial nerve III palsy, ptosis and movement limitation of the right eye. Our first clinical consideration was a pituitary apoplexy. Blood hormonal analysis revealed mild hyperprolactinemia and high follicle stimulating hormone level; PTH and calcium was high with glomerular filtration rate mildly to moderately decrease. A computed tomography scan, revealed an enlarged pituitary gland (3.5 cm) impinging upon the optic chiasm with bone involvement of the sella. Following contrast media administration, the lesion showed homogeneous enhancement with high-density focus that suggests hemorrhagic infarction of the tumor. Transsphenoidal endoscopic surgery was perfomed and adenomatous tissue was removed. Immunohistochemistry was positive for luteinizing hormone (LH) and follicular-stimulating hormone (FSH). A solid hypoechoic nodule (14 mm x 13 mm x 16 mm) was found in the caudal portion of the right thyroid lobe after a parathyroid ultrasound. A genetic test of Multiple Endocrine Neoplasia type 1 (MEN1) was negative. A right lower parathyroidectomy was performed and the pathologic study showed the presence of an encapsulated parathyroid carcinoma of 1.5 cm. A MEN type 4 genetic test was performed result was negative.

CONCLUSION

This case demonstrates an uncommon complication of GnRH agonist therapy in the setting of a pituitary macroadenoma and the casual finding of parathyroid carcinoma. It also highlights the importance of suspecting the presence of a multiple endocrine neoplasia syndrome and to carry out relevant genetic studies.

Metastatic Phaeochromocytoma: Spinning Towards More Promising Treatment Options

Phaeochromocytomas (PCC) and paragangliomas (PGL) are rare tumours arising from the chromaffin cells of the adrenal medulla (PCC) or the paraganglia located outside the adrenal gland (PGL). However, their incidence is likely to be underestimated; around 10% of all PCC/PGL are metastatic, with higher metastatic potential of PGLs compared to PCCs. If benign, surgery is the treatment of choice, but if metastatic, therapy is challenging. Here we review the currently existing therapy options for metastatic PCCs/PGLs including conventional chemotherapy (the original Averbuch scheme, but updated), radiopharmaceutical treatments (¹³¹I-MIBG, ⁹⁰Y- and ¹⁷⁷Lu-DOTATATE) and novel targeted therapies (anti-angiogenic tyrosine kinase inhibitors and mTORC1 inhibitors), emphasising future therapeutic approaches (HIF-2α and PARP inhibitors, temozolomide alone, metronomic temozolomide, somatostatin analogues) based on the oncogenic signalling pathways related to three different clusters comprising more than 20 well-characterised PCC/PGL susceptibility genes. We suggest that targeted combination therapies including repurposed agents may offer more effective future options worthy of exploration.

MECHANISMS OF ENDOCRINOLOGY: Cell cycle regulation in adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are rather rare endocrine tumors that often have a poor prognosis. The reduced survival rate associated with these tumors is due to their aggressive biological behavior, combined with the scarcity of effective treatment options that are currently available. The recent identification of the genomic alterations present in ACC have provided further molecular mechanisms to develop consistent strategies for the diagnosis, prevention of progression and treatment of advanced ACCs. Taken together, molecular and genomic advances could be leading the way to develop personalized medicine in ACCs similarly to similar developments in lung or breast cancers. In this review, we focused our attention to systematically compile and summarize the alterations in the cell cycle regulation that were described so far in ACC as they are known to play a crucial role in cell differentiation and growth. We have divided the analysis according to the major transition phases of the cell cycle, G1 to S and G2 to M. We have analyzed the most extensively studied checkpoints: the p53/Rb1 pathway, CDC2/cyclin B and topoisomerases (TOPs). We reached the conclusion that the most important alterations having a potential application in clinical practice are the ones related to p53/Rb1 and TOP 2. We also present a brief description of on-going clinical trials based on molecular alterations in ACC. The drugs have targeted the insulin-like growth factor receptor 1, TOP 2, polo-like kinase1, cyclin-dependent kinase inhibitors, p53 reactivation and CDC25.

Nutlin-3a as a novel anticancer agent for adrenocortical carcinoma with CTNNB1 mutation

Adrenocortical carcinoma (ACC) is a rare malignancy, and CTNNB1 is frequently mutated in ACC. Our study aims to screen for effective agents with antineoplastic activity against ACC with CTNNB1 mutation. In‐silico screening of the Genomics of Drug Sensitivity in Cancer (GDSC) database was conducted. Drug sensitivity in cells with CTNNB1 mutation was analyzed and further in vitro and in vivo studies were performed using the compound. Only one compound, Nutlin‐3a, an MDM2 inhibitor, was significantly sensitive in 18 cancer cells with CTNNB1 mutation. Further analysis of the 18 cells revealed no significant efficacy between cells with both CTNNB1 and TP53 mutations indicating concomitant TP53 mutation did not impact on drug efficacy. We verified that Nutlin‐3a inhibited cellular proliferation in ACC cell line NCI‐H295R which harbored CTNNB1 mutation but not in SW13 cells which did not. Nutlin‐3a induced cell apoptosis and G1 cell‐cycle arrest in NCI‐H295R cells. Nutlin‐3a also decreased cellular migration and inhibited epithelial‐to‐mesenchymal transition (EMT) process in terms of EMT index. Nutlin‐3a resulted in decreased β‐catenin level independent of p53 level in NCI‐H295R but not SW13 cells. We also evaluated the effect of Nutlin‐3a on hormonal secretion of NCI‐H295R cells and found it resulted in decreased levels of cortisol, androgen, and progesterone. Nutlin‐3a treatment inhibited ACC tumor growth with no observed toxicity in mice in vivo. Our study has revealed that Nutlin‐3a potently inhibits ACC with CTNNB1 mutation. How p53/MDM2 axis coordinates with Wnt/beta‐Catenin signaling in ACC warrants further study.

Pheochromocytomas and Hypertension

PURPOSE OF REVIEW

Pheochromocytomas and paragangliomas (PPGLs) are uncommon catecholamine-producing neuroendocrine neoplasms that usually present with secondary hypertension. This review is to update the current knowledge about these neoplasms, the pathophysiology, genetic aspects and diagnostic and therapeutic algorithms based on scientific literature mostly within the past 3 years.

RECENT FINDINGS

Eighty to eighty-five percent of PPGLs arise from the adrenal medulla (pheochromocytomas; PCCs) and the remainder from the autonomic neural ganglia (paragangliomas; PGLs). Catecholamine excess causes chronic or paroxysmal hypertension associated with sweating, headaches and palpitations, the presenting features of PPGLs, and increases the cardiovascular morbidity and mortality. Genetic testing should be considered in all cases as mutations are reported in 35-40% of cases; 10-15% of PCCs and 20-50% of PGLs can be malignant. Measurements of plasma-free metanephrines or 24-h urine-fractionated metanephrines help biochemical diagnosis with high sensitivity and specificity. Initial anatomical localization after biochemical confirmation is usually with computed tomography (CT) or magnetic resonance imaging (MRI). ¹²³Iodine metaiodobenzylguanidine (¹²³I-MIBG) scintigraphy, positron emission tomography (PET) or single-photon emission computed tomography (SPECT) is often performed for functional imaging and prognostication prior to curative or palliative surgery. Clinical and biochemical follow-up is recommended at least annually after complete tumour excision. Children, pregnant women and older people have higher morbidity and mortality risk. De-bulking surgery, chemotherapy, radiotherapy, radionuclide agents and ablation procedures are useful in the palliation of incurable disease. PPGLs are unique neuroendocrine tumours that form an important cause for endocrine hypertension. The diagnostic and therapeutic algorithms are updated in this comprehensive article.