Pheochromocytoma (PCC) is a rare neuroendocrine tumor that is often nonfunctional in its early stages, making detection difficult during the prodromal phase. Targeted radionuclide therapy using radiopharmaceuticals has been explored for treating PCC. We aimed to evaluate and compare the therapeutic efficacy of meta-[131I]iodobenzylguanidine ([131I]MIBG) and meta-[211At]astatobenzylguanidine ([211At]MABG) in vitro and in a PCC animal model. Astatine-211 was radiolabeled with a benzylguanidine precursor, and the crude product was purified using high-performance liquid chromatography, followed by formulation to prepare an injectable [211At]MABG. [131I]MIBG was obtained from the Korea Atomic Energy Research Institute. The stability of [211At]MABG was assessed in saline and human serum with or without sodium ascorbate. In vitro experiments included evaluating cellular uptake in PC-12 cells, colony formation inhibition (clonogenic assay), and DNA damage (Comet assay). In vivo studies were conducted using PC-12 tumor-bearing mice to assess biodistribution, tumor volume reduction, survival rates, and body weight changes. Immunohistochemical analyses of tumor proliferation and apoptosis were performed using Ki-67, proliferating cell nuclear antigen (PCNA), and the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. [211At]MABG was successfully synthesized with a radiochemical yield of 48.4% (decay-corrected). The radiochemical purity (RCP) was 99.3%, and the specific activity was 1.27-8.13 MBq·nmol-1 at the end of synthesis (n = 3). In chemical stability tests of [211At]MABG, when sodium ascorbate was not added, the RCP was 76% at 24 h after production; however, when sodium ascorbate was added, its purity was 92% at the same time. In vitro uptake assays revealed that [211At]MABG exhibited higher cellular uptake in PC-12 cells compared with [211At]NaAt and [131I]MIBG, initially accumulating in the cytosol and progressively increasing over 24 h. DNA double-strand breaks were confirmed using the Comet assay. Biodistribution studies demonstrated that administration of [211At]MABG containing sodium ascorbate reduced thyroid uptake and enhanced tumor accumulation of [211At]MABG. Treatment with 0.93 MBq [211At]MABG resulted in superior tumor suppression compared with 19.25 MBq [131I]MIBG and improved survival rates. Immunohistochemical analyses confirmed decreased tumor proliferation and increased apoptosis following [211At]MABG treatment. The stability of [211At]MABG in human serum was significantly enhanced by sodium ascorbate. Even at doses 20 times lower than [131I]MIBG, [211At]MABG demonstrated superior antitumor efficacy without inducing substantial weight loss. These findings suggest that [211At]MABG may serve as a promising alternative for treating malignant PCC.

Pheochromocytoma and paraganglioma (PPGL) are rare tumors that occur in the adrenal medulla and extra-adrenal tissues, respectively. The prognosis and tumor microenvironment (TME) of pseudohypoxic PPGL as a major entity have not been fully described. Based on the clinical database of 65 patients with PPGL, we assessed the morphological features as well as the immunohistochemistry of pseudohypoxia-related proteins (SDHB and CAIX) and TME-related immune cell markers. Furthermore, we compared the relapse-free survival (RFS) rates in localized patients between the pathological subgroups. Among 50 available specimens, 84% and 30% of the cases exhibited at least one morphological adverse feature including vascular/capsular invasion and a Ki-67 index > 3%, respectively. The SDHB and CAIX positivity rates were 81% and 51%. Concerning the immune cell markers, the CD163-positive cell numbers were higher in hypoxia-associated PPGL composed of SDHB-negative or CAIX-positive cases than in non-hypoxia PPGL (median 66 vs. 23/mm2). Concerning prognosis, RFS rates were significantly lower in cases with Ki-67 indices > 3% and SDHB-negativity than in those with Ki-67 indices ≤ 3% and SDHB-positivity (3-year rate: 64% vs. 100%, P < 0.001; 57% vs. 100%, P = 0.03). In contrast, RFS was comparable between CAIX-positive and CAIX-negative PPGL cases. Our analyses suggested that SDHB-deficient PPGL exhibited a higher incidence of relapse. Furthermore, M2 macrophage infiltration in TME might be crucial in pseudohypoxic PPGL pathogenesis.

Malignant pheochromocytomas are infrequent tumors that have a poorer prognosis compared to their benign counterparts. The administration of chemotherapy to patients with pheochromocytoma can result in adverse side effects and a reduced life quality. Alternative and more targeted treatment strategies, such as gene therapy significantly improve the patients' survival rate and life expectancy. Caspase-3 is a key apoptosis regulator activated by cancer treatments. Recent research shows it also influences tumor relapse and angiogenesis, complicating its role in cancer progression. Further exploration of Caspase-3's diverse functions is needed to clarify its impact on cancer development. In this study, we established Caspase-3 over expressed pheochromocytoma cell line by the use of lentiviral vector technology. Caspase 3 over expression by up to 3fold led to increase in cell proliferation by up to 12 %. Moreover, increasing in Caspase 3 level of expression resulted in more invasiveness and metastasis. By this way, the wound closure percentage for PC-12 Casp3 + cells reached 76.2 %, which is significantly higher compared to the 52.8 % observed in mock cells. Casp3 + cells were also significantly more sensitive to cisplatin than mock cells with Ic50 of 158.4 μM and 219.5uM respectively according to MTT assay which confirmed by apoptosis assay. Hence, targeting Caspase-3 as a therapeutic approach may enhance the cancer cell sensitivity to chemotherapy, but also increase the cancer cell proliferation, metastases and invasion which may works as a double edge sword. CONCLUSION: understanding the effects of Caspase 3 over expression on cancer cells could inspire innovative therapies targeting its non-apoptotic actions, potentially improving cancer treatment outcomes.

Pheochromocytomas and paragangliomas (PPGLs) are infrequent neuroendocrine hypervascular neoplasms arising within different sites of the paraganglion system. They are divided into sympathetic (including pheochromocytomas and extraadrenal paragangliomas) and parasympathetic extraadrenal tumors. These tumors are usually not malignant and grow slowly; about 90% of them are found in the adrenal paraganglia (pheochromocytomas). Extraadrenal tumors are most frequently located in the abdominal cavity (85%), followed by the thoracic cavity (12%), and head and neck (3%). About 25% of PPGLs are related to germline mutations, which are risk factors for multifocal and metastatic disease. In PPGL diagnostics, laboratory, biochemical, and imaging (anatomical and functional) examinations are used. Surgery is the standard management choice for locoregional disease. For patients who are not candidates for surgery and who have stable, not-growing, or slow-growing tumors, active observation or other less invasive techniques (i.e., stereotactic surgery, hypofractionated stereotactic radiotherapy) are considered. In metastatic disease, systemic therapies (tyrosine kinase inhibitors [TKIs], mTORC1 inhibitor everolimus, immunotherapy, cold somatostatin analogs [biotherapy], and radioligand therapy) are used. The prognosis for PPGLs is quite good, and the 5-year survival rate is >90%. The goal of this paper is to review knowledge on the etiopathogenesis, current diagnostics, and therapy for PPGL patients. Our paper is particularly focused on the current management of PPGLs.

The approval in 2017 by the European Medicines Agency (EMA) and in 2018 by the US Food and Drug Administration (FDA) of radioligand therapy (RLT) led to its wide application in therapeutic management of neuroendocrine neoplasms (NENs). However, the indications are currently limited to certain specific histotypes belonging to the broader NEN's family, mainly advanced well-differentiated gastro-entero-pancreatic NENs. As a consequence, several other tumors of the NEN spectrum that can potentially benefit, due to their biological characteristics, from RLT are still ineligible and can be considered "RLT-orphans". Among those, the subgroup of NENs originating from the sympathetic-adrenal-medullary (SAM) axis can be listed. This paper discusses the state of art and perspectives of the theragnostic applications in pheochromocytomas and paragangliomas, considering both the traditional theragnostic model - with radiolabelled metaiodobenzylguanidine (MIBG) - and the innovative one with radiolabeled somatostatin analogs (SSAs), that will hopefully become available for these patients in the near future.

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors derived from the paraganglia. These tumors frequently secrete excessive amounts of catecholamines leading to cardiovascular and gastrointestinal complications. While all pheochromocytomas and paragangliomas possess the potential for metastasis, actual metastatic occurrences are observed in approximately one third of cases. The metastases primarily affect the lymph nodes, skeletal system, liver, and lungs. Furthermore, patients often experience a reduced overall survival rate attributed to factors such as tumor size, disease advancement, and excessive catecholamine secretion. For several decades, treatment options for patients diagnosed with metastatic pheochromocytomas and paragangliomas have primarily included combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine, along with Iodine-131-metaiodobenzylguanidine. However, significant advancements in scientific research over the past 25 years have enabled a comprehensive characterization of these tumors from biochemical, molecular, and diagnostic standpoints, resulting in the identification of new therapeutic alternatives for affected patients. In the last decade, we have witnessed the introduction of innovative systemic therapies specifically designed for those with metastatic pheochromocytomas and paragangliomas. In this review, we aim to present findings on the efficacy, safety, and overall activity from prospective clinical trials involving radiopharmaceuticals and tyrosine kinase inhibitors, and we will also outline the prospective advantages of additional novel therapies currently under evaluation.

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors derived from chromaffin cells, with 80-85% originating in the adrenal medulla and 15-20% from extra-adrenal chromaffin tissues (paragangliomas). Approximately 30-40% of PPGLs have a hereditary component, making them one of the most genetically predisposed tumor types. Recent advances in genetic research have classified PPGLs into three molecular clusters: pseudohypoxia-related, kinase-signaling, and WNT-signaling pathway variants. Specifically, the detection of SDHB-related tumors indicates an increased risk of metastatic disease, which may impact decisions regarding functional imaging in patients with high suspicion of metastasis and influence targeted treatment strategies. Diagnosis of PPGLs primarily relies on biochemical testing, measuring catecholamines or their metabolites in plasma or urine. However, molecular testing, functional imaging, and targeted therapies have greatly enhanced diagnostic precision and management. Personalized treatment approaches based on genetic profiling are becoming integral to the clinical management of these tumors. In South American countries like Colombia, functional imaging techniques such as positron emission tomography/computed tomography (PET/CT) with tracers like 18F-DOPA, 18F-fluorodeoxyglucose (18F-FDG), and 68Ga-DOTA-conjugated somatostatin receptor-targeting peptides (68Ga-DOTA-SST) are used to guide follow-up and treatment strategies. Radionuclide therapy with lutetium-177 DOTATATE is employed for patients showing uptake in 68Ga-DOTA-SST PET/CT scans, while access to 131-MIBG therapy remains limited due to high costs and availability. Recent clinical trials have shown promise for systemic therapies such as sunitinib and cabozantinib, offering potential new options for patients with slow or moderate progression of PPGLs. These advancements underscore the potential of personalized and targeted therapies to improve outcomes in this challenging patient population.

Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours that arise not only in adulthood but also in childhood and adolescence. Up to 70-80% of childhood PPGL are hereditary, accounting for a higher incidence of metastatic and/or multifocal PPGL in paediatric patients than in adult patients. Key differences in the tumour biology and management, together with rare disease incidence and therapeutic challenges in paediatric compared with adult patients, mandate close expert cross-disciplinary teamwork. Teams should ideally include adult and paediatric endocrinologists, oncologists, cardiologists, surgeons, geneticists, pathologists, radiologists, clinical psychologists and nuclear medicine physicians. Provision of an international Consensus Statement should improve care and outcomes for children and adolescents with these tumours.

Pheochromocytomas and paragangliomas (PPGLs) are orphan tumors with the potential to spread to distant organs such as the lymph nodes, the skeleton, the lungs, and the liver. These metastatic tumors exhibit high rates of morbidity and mortality due to their frequently large tumor burden, the progression of the disease, and the excessive secretion of catecholamines that lead to cardiovascular disease and gastrointestinal dysmotility. Several molecular drivers responsible for the development of PPGLs have been described over the last 30 years. Although therapeutic options are limited, substantial progress has been made in the recognition of effective systemic therapies for these tumors. Successful clinical trials with radiopharmaceuticals such as high-specific-activity meta-iodobenzylguanidine and tyrosine kinase inhibitors such as cabozantinib and sunitinib have been recently published. This review will discuss the results of these studies and their impact on current clinical practices. In addition, this review will provide valuable information on how to design clinical trials to treat patients with metastatic PPGLs with novel medications.

Pheochromocytoma and paraganglioma (PPGL) represent a group of rare neuroendocrine tumors known for their potential to metastasize. This study provides a comprehensive retrospective evaluation of 15 patients diagnosed with metastatic or recurrent PPGL at our institution over a two-decade span (2000-2020). Our primary objectives were to delineate the long-term clinical outcomes and pinpoint key prognostic determinants. Median duration from initial PPGL diagnosis to the onset of metastasis or recurrence stood at 5.8 years. Predominant sites for metastasis included the bone, lung, lymph nodes, and peritoneum. A salient finding was that surgical interventions targeting metastatic lesions significantly improved prognosis. Further analysis revealed that a Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) exceeding 7 closely associated with unfavorable outcomes. These insights not only underscore the clinical variability of PPGL's progression but also highlight the pivotal role of surgical management for metastatic or recurrent cases. The value of the PASS score as an informative prognostic tool was evident, suggesting its utility in shaping future therapeutic approaches. Given the intricacies of PPGL, collaborative studies involving larger patient cohorts will be crucial to optimize management strategies and prognostication.

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors derived from chromaffin cells in the autonomic nervous system. Depending on their location, these tumors are capable of excessive catecholamine production, which may lead to uncontrolled hypertension and other life-threatening complications. They are associated with a significant risk of metastatic disease and are often caused by an inherited germline mutation. Although surgery can cure localized disease and lead to remission, treatments for metastatic PPGL (mPPGL)-including chemotherapy, radiopharmaceutical agents, multikinase inhibitors, and immunotherapy used alone or in combination- aim to control tumor growth and limit organ damage. Substantial advances have been made in understanding hereditary and somatic molecular signaling pathways that play a role in tumor growth and metastasis. Treatment options for metastatic disease are rapidly evolving, and this paper aims to provide a brief overview of the management of mPPGL with a focus on therapy options.

Pheochromocytomas and paragangliomas (PPGL) are neuroendocrine tumors which secrete catecholamines, causing cardiovascular compromise. While isolated tumors and locoregional disease can be treated surgically, treatment options for metastatic disease are limited, and no targeted therapies exist. Approximately 25% of PPGL are causatively associated with germline pathogenic variants, which are known risk factors for multifocal and metastatic PPGL. Knowledge of somatic driver mutations continues to evolve. Molecular classification of PPGL has identified three genomic subtypes: Cluster 1 (pseudohypoxia), Cluster 2 (kinase signaling) and Cluster 3 (Wnt-altered). This review summaries recent studies characterizing the tumor microenvironment, genomic drivers of tumorigenesis and progression, and current research on molecular targets for novel diagnostic and therapeutic strategies in PPGL.

Metastatic Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors characterized by high morbidity and limited systemic treatment options, mainly based on radiometabolic treatments or chemotherapy. Based on the preclinical rationale that PGGLs carcinogenesis relies on angiogenesis, treatment with tyrosine kinase inhibitors (TKI) may represent another viable therapeutic option.

We conducted a prospective phase II study in patients with metastatic or unresectable PGGLs. Patients received sunitinib (50 mg daily for 4 weeks, followed by a 2-week rest period) until progressive disease (PD), unacceptable toxicity or consent withdrawal. The primary endpoint was 12-month progression-free survival (PFS) rate; secondary endpoints were safety overall response rate (ORR) according to RECIST 1.1 criteria and overall survival (OS). EudraCT Number: 2011-002632-99.

Fifty patients were included. At a median follow-up of 71.7 months (IQR 35.4-100.1), the 1 year-PFS rate was 53.4 % (95 %CI 41.1-69.3) and median PFS was 14.1 months (95 % CI 8.9-25.7). ORR was 15.6 %, the median OS was 49.4 months (95 %CI 21.2-NA), and grade 3 or higher treatment-related adverse events were reported in 34 % patients. No significant correlation was found between specific genetic alterations or genomic clusters and sunitinib efficacy.

Sunitinib is an active drug in patients with advanced PGGLs, capable of inducing prolonged disease control with a manageable toxicity profile.

Pheochromocytomas and paragangliomas are distinctive neuroendocrine tumors which frequently produce excess catecholamines with resultant cardiovascular morbidity. These tumors have a strong genetic component, with up to 40% linked to hereditary pathogenic variants; therefore, germline genetic testing is recommended for all patients. Surgical resection offers the only potential cure in the case of localized disease. Given the potential for catecholaminergic crises, appropriate perioperative management is crucial, and all patients should undergo alpha-adrenergic blockade before resection. Therapeutic options for metastatic disease are limited and include surgical debulking, radiopharmaceutical therapies, and conventional chemotherapy.

Recently, the treatment landscape for metastatic pheochromocytomas and paragangliomas (MPPGL) has seen both progress and setbacks. We provide an up-to-date review of the multimodality management of MPPGL and discuss novel opportunities and current challenges in the treatment landscape. Given the unique clinical presentation of MPPGL, we discuss the management of hormone-related clinical sequelae and traditional modalities of therapy. Advances in the understanding of the molecular biology of these diverse tumors have enabled novel strategies such as augmenting DNA damage by targeted delivery of radionuclides such as 131I and 177Lu, abrogating tumor angiogenesis, hypoxia resistance, and DNA damage repair. Despite progress, we address the significant challenges still faced by patients and researchers engaged in efforts to improve outcomes in these rare cancers.

The understanding of the nature of catecholamine-secreting tumors has changed significantly in recent years, affecting terminology and classification. Phaeochromocytoma/paraganglioma (PCC/PG) is a rare neuroendocrine tumor from chromaffin tissue that produces and secretes catecholamines. The incidence of PCC/PG is relatively low, with 2-8 cases per 1 million population per year; among patients with arterial hypertension, their prevalence is 0.2-0.6%. However, delayed diagnosis of PCC/PG is associated with a high risk of cardiovascular complications and a high mortality rate. The consensus presents the clinical manifestations of the disease with an emphasis on the course of arterial hypertension as the most common symptom in PCC/PG; modern ideas about the features of diagnosis, aspects of preoperative preparation, treatment, and follow-up of patients with PCC/PG are considered.

Data regarding treatment options and their efficacy for metastatic paragangliomas (mPPGL) is limited. This study aims to report a single center experience in treating mPPGL, comparing the efficacy and safety of various treatment approaches.

Retrospective analysis of patients with mPPGL treated at an Endocrinology Department of a cancer institute between January 2000 and October 2022.

We analyzed 25 patients with mPPGL, 8 pheochromocytomas and 20 paragangliomas (12% multifocal), followed for a median of 9 [4; 14] years. Surgical approach, aimed at the primary tumor or at debulking of metastases, was the only treatment achieving complete response: 87% in primary tumor and 87.5% with debulking of metastases. These were long-lasting results with a duration of 69 (23.8; 136.8) months in primary tumor removal and 35.1 (15.3; 41) months in metastases debulking. As for other therapeutic approaches, such as radioactive isotopes, tyrosine kinase inhibitors, chemotherapy and external beam radiotherapy, the main outcome was stable disease, with few partial responses. At the last follow-up, 66% of the patients were alive, 15.4% were in remission and 84.6% had stable disease. Median overall survival was 14 years. The 5-year and 10-year survival rates from primary tumor diagnosis were 77.9% and 66.9% respectively, and from metastasis diagnosis were 67.4% and 55.6%, respectively.

This is the only European single center analysis addressing outcomes of different therapies in mPGL. The results support surgery as a first-line treatment, being the only approach that may achieve complete response with satisfactory and long-lasting results.

Carotid body tumors (CBTs) are neoplasms that occur at the bifurcation of the carotid artery and are pathologically classified as paragangliomas. In the 4th edition of the WHO classification, paragangliomas are categorized as neoplasms with malignant potential. Clinically, about 5% of CBTs present with malignant features such as metastasis. Currently, it is challenging to distinguish between tumors with benign courses and those that present malignantly. Recent advances in genetic testing have elucidated the genetic characteristics of paragangliomas, including carotid body tumors. Over 20 genes have been identified as being involved in tumor development. Particularly in head and neck paragangliomas, abnormalities in genes related to succinate dehydrogenase are frequently observed. Research is ongoing to understand the mechanisms by which these genes contribute to tumor development. The definitive treatment for CBTs is surgical resection. These tumors are prone to bleeding and often adhere firmly to the carotid artery, making intraoperative bleeding control challenging. The risk of lower cranial nerve paralysis is relatively high, and there is a risk of stroke because of manipulation of the carotid artery. Preoperative evaluation with angiography is essential, and a multi-disciplinary surgical team approach is necessary. In cases where the tumor is difficult to resect or has metastasized, radiation therapy or chemotherapy are employed. Clinical trials involving targeted molecular therapies and radiopharmaceuticals have recently been conducted, with some applied clinically. The development of various new treatments is anticipated, providing hope for therapeutic options in refractory cases.

Paraganglioma is a rare neuroendocrine tumor that arises outside of the adrenal gland, typically originating from the chromaffin tissue of the sympathetic or parasympathetic ganglia. It can manifest at any age, with a peak incidence occurring between 40 and 50 years old. When the tumor secretes catecholamines, it is referred to as "functional." Currently, there is no standardized therapeutic approach. However, the management of metastatic forms is based on a systemic treatment with tri-chemotherapy. Herein, we present the case of a young male patient with heavily metastatic functional malignant paraganglioma, which represents the first case managed in our department. After seven months of Somatuline treatment, our patient experienced disease progression. Subsequently, he received tri-chemotherapy comprising cyclophosphamide, vincristine, and dacarbazine, which proved to be suboptimal due to poor hematological tolerance and a progression-free survival of less than three months. In the third line of treatment, Sunitinib was administered, but the therapeutic response was poor, with clinical progression observed within two months, ultimately leading to the patient's demise at home. The overall survival was two years.

Objectives: To summarize the clinicopathological and genetic features of malignant paragangliomas in head and neck cancer and to explore the appropriate treatment options for this rare lesion. Methods: Six patients harboring head and neck malignant paraganglioma from Beijing Tongren Hospital were retrospectively reviewed. The clinicopathological characteristics, gene mutations, and prognosis of these patients were analyzed. Results: Of these 6 patients, 3 were male and 3 were female; 4 patients harbored malignant carotid body tumors, and two had malignant vagal paragangliomas. Three patients had cervical lymph node metastasis, two presented with lung and bone metastasis, and 1 had lung and liver metastasis. Of the 6 patients, four underwent surgical resection, and the other two patients denied surgery and instead received chemotherapy with paclitaxel, ifosfamide, and dacarbazine. These 2 patients with vagal paraganglioma received postoperative radiotherapy. All 6 patients are still alive at the present time, with a median follow-up time of 66 months. Positive Ki-67 expression in tumor tissue ranged from 1% to 40%. Genetic mutations in SDHD, SDHB, ATR, and MAP3K13 were identified in 4 patients. Conclusions: After comprehensive treatment, head and neck malignant paraganglioma can attain a favorable prognosis. Genetic mutations are commonly detected in patients with malignant paragangliomas. This study also identified mutations in ATR and MAP3K13 in these patients.

Pheochromocytomas (PCC) and paragangliomas (PGL) (collectively PPGL) are a type of rare hypervascular neuroendocrine tumors that are very challenging to treat. This study aimed to determine the efficacy and safety of the multi-tyrosine kinase inhibitor anlotinib for the treatment of locally advanced or metastatic (LA/M) PPGL.

A total of 37 eligible patients with unresectable or progressive LA/M PPGL were enrolled. Of them, 27 patients received anlotinib alone (n = 19) or in combination (n = 8) with radionuclide therapies, including peptide receptor radionuclide therapy (PRRT) and iodine 131 meta-iodobenzylguanidine (131I-MIBG). The primary endpoints included objective response rate (ORR), defined as partial response (PR) or complete response (CR), and disease-control rate, defined as PR, CR, or stable disease (SD). The secondary endpoints were progression-free survival (PFS), duration of response, and drug safety.

In the efficacy evaluation for all 27 patients, the ORR was 44.44% (95% CI: 24.4%-64.5%) and disease-control rate was 96.29% (95% CI: 88.7%-100%). Twelve cases (44.44%) achieved PR, 14 (51.85%) SD. The median PFS was 25.2 months (95% CI: 17.2 months to not reached). PFS was shorter in the anlotinib monotherapy group than in the group receiving anlotinib in combination with radionuclide therapy (P = .2). There were no serious treatment-related AEs.

Anlotinib monotherapy or in combination with radionuclide therapies shows promising efficacy and safety for the treatment of LA/M PCC and PGL. Multi-tyrosine kinase inhibitors might represent a novel therapeutic strategy for patients with PPGL; however, large-scale prospective randomized, blinded, controlled clinical research studies are required.

The treatment of metastatic pheochromocytoma is challenging. We report a case of a woman with recurrent pheochromocytoma with multiple metastases who achieved excellent response after 4 cycles of 177 Lu-DOTATATE therapy. She did not experience any observable adverse effects. Her disease was still stable 6 months after the fourth cycle of treatment.

Metastatic disease affects approximately 15% to 17% of patients with pheochromocytomas and paragangliomas (PPGLs). Unfortunately, treatment options for metastatic PPGLs are limited and rely on small, nonrandomized clinical trials. The impact of germline mutation status on systemic treatment outcomes remains unclear. To address these gaps, we retrospectively evaluated treatment outcomes in patients with PPGL.

Between December 2004 and December 2021, 33 patients were diagnosed with metastatic PPGLs and received systemic treatment at the Department of Oncology, Asan Medical Center, Seoul, South Korea.

The median age of the patients was 49. Germline mutations were revealed in nine patients (39.1%) out of 23 who underwent germline testing, with SDHB mutation being the most frequent in 5 patients. Cyclophosphamide, vincristine, and dacarbazine (CVD) chemotherapy was administered to 18 patients, with an objective response rate (ORR) of 22% and a disease control rate (DCR) of 67%. The median progression-free survival (PFS) was 7.9 and the median overall survival (OS) was 36.2 months. Sunitinib was given to 6 patients, which had an ORR of 33%, a DCR of 83%, and a median PFS of 14.6 months. Notably, patients with SDHB/SDHD mutation (4 patients and one patient, respectively) who received CVD treatment had a significantly better OS than those without (median OS 94.0 months vs. 13.7 months, P = .01).

Our study reveals that CVD and sunitinib are effective treatments for metastatic PPGLs. The results are consistent with previous studies and patients with SDHB and SDHD mutations may benefit most from CVD treatment.

Malignant carotid body tumors (MCBT) are rare and diagnosed after detection of nodal or distant metastases. This systematic review (SR) focuses on MCBT initially approached by surgery. Preferred Reporting Items for SR and Meta-Analysis (MA) guided the articles search from 2000 to 2023 on PubMed, Scopus, and Web of Science. Among 3548 papers, 132 (337 patients) were considered for SR; of these, 20 (158 patients) for MA. Malignancy rate was 7.3%, succinate dehydrogenase (SDH) mutation 17%, age at diagnosis between 4th and 6th decades, with a higher prevalence of females. MCBTs were mostly Shamblin III, with nodal and distant metastasis in 79.7% and 44.7%, respectively. Malignancy should be suspected if CBT >4 cm, Shamblin III, painful or otherwise symptomatic, at the extremes of age, bilateral, with multifocal disease, and SDHx mutations. Levels II-III clearance should be performed to exclude nodal metastases and adjuvant treatments considered on a case-by-case basis.

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time. In addition, SDHB pathogenic variants support tumour growth through high levels of the oncometabolite succinate and other mechanisms related to cancer initiation and progression. As a result, pseudohypoxia and upregulation of genes related to the hypoxia signalling pathway occur, promoting the growth, migration, invasiveness and metastasis of cancer cells. These factors, along with a high rate of metastasis, support early surgical intervention and total resection of PPGLs, regardless of the tumour size. The treatment of metastases is challenging and relies on either local or systemic therapies, or sometimes both. This Consensus statement should help guide clinicians in the diagnosis and management of patients with SDHB PPGLs.

Malignant paragangliomas (M-PGL) are a group of neuroendocrine tumors that originate from chromaffin cells. The most common location for PGL is the head and neck, which comprise 65-70% of all PGL, and the M-PGL accounts for 0.6% of all head and neck cancers. It is a rare tumor, with an incidence of 2-8 per million. Diagnosing PGL can be challenging, and treatment for metastatic disease is usually not curative.

A 66-year-old woman was diagnosed with left cervical pain and laterocervical mass in March 2015. Octreotide scintigraphy showed intense uptake in the cervical mass, two pulmonary micronodules of 4-5 mm, and another lesion in the lumbar region (L3-L4). The final diagnosis was malignant nonsecretory PGL with adjacent tissue involvement and distant metastases. After three different treatments with minimal symptomatic improvement, 177Lu-DOTATATE was requested off-label. With a dose of 7,400 MBq until January 2018, the patient showed remarkable symptomatic pain improvement and a decrease in tumor size.

We believe that our case report provides relevant information that can be considered in similar cases. First, the patient tripled the expected survival in such a clinical setting, and this benefit seems to rely on 177Lu-DOTATATE treatment. Second, we documented an early symptomatic response to this treatment but a long-term delayed volumetric radiographic response.

Cabozantinib is an oral multi-tyrosine kinase inhibitor (TKI) that has been approved in Europe for advanced renal cell carcinoma, hepatocellular carcinoma, locally advanced and metastatic medullary thyroid carcinoma (MTC) and radioiodine-refractory differentiated thyroid cancer. Merkel cell carcinoma (MCC) is a rare and highly aggressive cutaneous malignant neuroendocrine tumour that usually presents in sun-exposed skin areas of immunosuppressed patients. Conflicting data exist about cabozantinib for MCC and this TKI is currently under investigation in several onco-endocrine frameworks.

We herein report a case of an 83-year-old man who was diagnosed with MCC during the treatment of an advanced metastatic MTC. The diagnosis of MCC was established based on clinical, histopathologic evaluation and immunohistochemistry. A systematic review of the literature on cabozantinib use for advanced endocrine and neuroendocrine tumours has been performed.

The patient was initially treated with surgery and adjuvant radiotherapy. Cabozantinib was therefore started to control both MTC and MCC. After 24 months, no sign of local or metastatic MCC relapse was evidenced.

Promising data on cabozantinib treatment for endocrine and neuroendocrine neoplasms is recently emerging in the literature. In our clinical case, we reported that, besides the good response for the MTC, cabozantinib also seems to effectively control metastatic MCC, along with efficient surgery and adjuvant radiotherapy. Further investigations are needed to determine the efficacy and safety of cabozantinib in MCC patients and in off-label endocrine tumours.

The therapeutic options for metastatic pheochromocytomas/paragangliomas (mPPGLs) include chemotherapy with cyclophosphamide/vincristine/dacarbazine (CVD), temozolomide monotherapy, radionuclide therapies, and tyrosine kinase inhibitors such as sunitinib. The objective of this multicenter retrospective study was to evaluate and compare the responses of mPPGLs including those with pathogenic variants in succinate dehydrogenase subunit B (SDHB), to different systemic treatments.

This is a retrospective analysis of treatment responses of mPPGL patients (n = 74) to systemic therapies.

Patients with mPPGLs treated at 6 specialized national centers were selected based on participation in the ENSAT registry. Survival until detected progression (SDP) and disease-control rates (DCRs) at 3 months were evaluated based on imaging reports.

For the group of patients with progressive disease at baseline (83.8% of 74 patients), the DCR with first-line CVD chemotherapy was 75.0% (n = 4, SDP 11 months; SDHB [n = 1]: DCR 100%, SDP 30 months), with somatostatin peptide receptor-based radionuclide therapy (PPRT) 85.7% (n = 21, SDP 17 months; SDHB [n = 10]: DCR 100%, SDP 14 months), with 131I-meta-iodobenzylguanidine (131I-MIBG) 82.6% (n = 23, SDP 43 months; SDHB [n = 4]: DCR 100%, SDP 24 months), with sunitinib 100% (n = 7, SDP 18 months; SDHB [n = 3]: DCR 100%, SDP 18 months), and with somatostatin analogs 100% (n = 4, SDP not reached). The DCR with temozolomide as second-line therapy was 60.0% (n = 5, SDP 10 months; SDHB [n = 4]: DCR 75%, SDP 10 months).

We demonstrate in a real-life clinical setting that all current therapies show reasonable efficacy in preventing disease progression, and this is equally true for patients with germline SDHB mutations.

Temporal bone paragangliomas (TBPs) are indolent, classically benign and highly vascular neoplasms of the temporal bone. There are two types of TBPs, tympanomastoid paragangliomas (TMPs) and tympanojugular paragangliomas (TJPs). The most common symptoms are hearing loss and pulsatile tinnitus. Diagnostic workup, besides conventional physical and laboratory examinations, includes biochemical testing of catecholamine and genetic testing of SDHx gene mutations as well as radiological examination. Although surgery is traditionally the mainstay of treatment, it is challenging due to the close proximity of tumor to critical neurovascular structures and thus the high risk of complications, especially in patients with advanced lesions. Radiotherapy and active surveillance have been increasingly recommended for selected patients. Decision on treatment should be made comprehensively. Curative effect depends on various factors. Long-term follow-up with clinical, laboratory, and radiological examinations is essential for all patients.

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, developed respectively in the adrenal medulla and in extra-adrenal locations. Their malignancy is defined by the presence of distant metastases. Forty percent of them are inherited and can be part of different hereditary syndromes. Their management is ensured in France by the multidisciplinary expert centers of the ENDOCAN-COMETE national network "Cancers of the Adrenal gland", certified by the National Cancer Institute and discussed within multidisciplinary team meetings. The diagnostic and therapeutic work-up must be standardized, based on an expert analysis of clinical symptoms, hormonal biological secretions, genetics, morphological and specific metabolic imaging. In the context of a heterogeneous survival sometimes beyond seven to ten years, therapeutic intervention must be justified. This is multidisciplinary and relies on surgery, interventional radiology, external or internal radiotherapy and medical treatments such as sunitinib or dacarbazine and temodal chemotherapy. The personalized approach based on functional imaging fixation status and genetics is progressing despite the extreme rarity of this disease.

Retrospective Cohort Study.

To describe surgeries and treatment outcomes of metastatic pheochromocytomas and paragangliomas (PPGLs) on the spine.

We reviewed a cohort of 18 patients with spinal PPGLs who were consecutively treated in our spinal center. Their clinical data was reviewed. The survival period and its relevant factors was then analyzed.

The cohort included ten cases of pheochromocytomas and eight paragangliomas. The local pain and neurological deficits were the two most common symptoms. One third of the spinal PPGLs were diagnosed as functional tumors, arousing secondary hypertension. The imaging features were consistent with those of osteolytic lesions. The surgical strategies for the cohort included percutaneous vertebroplasty, neurological decompression and partial tumor resection, and total en-bloc resection. The postoperative courses were uneventful except 1 patient developed heart failure. The adjuvant therapies were implemented in 6 patients with 131I-MIBG, five with radiotherapy, two with chemotherapy, and 1 with target therapy. The median survival period was 39 months, and the overall survival rate of 1 year was 77.8% (14/18). The patients' Karnofsky performance scores were positively correlated with the survival period (P < .05).

Surgery is indicated for intractable local pain and neurological impairment in the patients with spinal PPGLs. Palliative surgical strategies, including neurological decompression and partial tumor resection, could bring fair outcomes, especially for the patients in poor physical conditions.

In this comprehensive review, we aimed to discuss the current state-of-the-art medical imaging for pheochromocytomas and paragangliomas (PPGLs) diagnosis and treatment. Despite major medical improvements, PPGLs, as with other neuroendocrine tumors (NETs), leave clinicians facing several challenges; their inherent particularities and their diagnosis and treatment pose several challenges for clinicians due to their inherent complexity, and they require management by multidisciplinary teams. The conventional concepts of medical imaging are currently undergoing a paradigm shift, thanks to developments in radiomic and metabolic imaging. However, despite active research, clinical relevance of these new parameters remains unclear, and further multicentric studies are needed in order to validate and increase widespread use and integration in clinical routine. Use of AI in PPGLs may detect changes in tumor phenotype that precede classical medical imaging biomarkers, such as shape, texture, and size. Since PPGLs are rare, slow-growing, and heterogeneous, multicentric collaboration will be necessary to have enough data in order to develop new PPGL biomarkers. In this nonsystematic review, our aim is to present an exhaustive pedagogical tool based on real-world cases, dedicated to physicians dealing with PPGLs, augmented by perspectives of artificial intelligence and big data.

Peptide receptor radionuclide therapy (PRRT) for advanced pheochromocytomas and paragangliomas (PPGLs) has received increasing attention. The purpose of this article is to evaluate the efficacy and safety of PRRT in patients with metastatic or inoperable PPGLs by meta-analysis.

A literature search was conducted in PubMed, Embase, Scopus, and Cochrane Library databases up to November 2022. All articles on PRRT for PPGLs were searched, and appropriate data were included for analysis. The measures evaluated included objective response rate (ORR), disease control rate (DCR), clinical response rate, biochemical response rate, progression-free survival (PFS), overall survival (OS), and adverse events. Statistical analysis was performed using Stata 16.0 and the R programming language, data were combined using a random-effects model, and the results were presented using forest plots.

A total of 20 studies with 330 patients were included in the analysis. The results showed that ORR and DCR were 20.0% (95% CI: 12.0%-28.0%) and 90.0% (95% CI: 85.0%-95.0%), respectively. Clinical and biochemical responses were 74.9% (95% CI: 56.3%-90.2%) and 69.5% (95%CI: 40.2%-92.9%). Median PFS and median OS were 31.79 (95% CI:21.25-42.33) months and 74.30 (95% CI: 0.75-147.84) months, respectively. Any grade of hematotoxicity and nephrotoxicity occurred in 22.3% (95% CI:12.5%-33.5%) and 4.3% (95% CI:0.2%-11.4%) patients. Grade 3-4 hemotoxicity occurred in 4.3% (95% CI:0.2%-11.4%) and grade 3-4 nephrotoxicity in 4/212 patients. Additionally, Treatment was discontinued in 9.0% (95% CI: 0.5%-23.3%) patients and one patient died as a result of a toxicity.

Patients with metastatic or inoperable PPGLs can be effectively treated with PRRT, and it has a favorable safety profile.

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022359232.

Pheochromocytomas (PCCs) are rare neuroendocrine tumors derived from the chromaffin cells of the adrenal medulla. When these tumors have an extra-adrenal location, they are called paragangliomas (PGLs) and arise from sympathetic and parasympathetic ganglia, particularly of the para-aortic location. Up to 25% of PCCs/PGLs are associated with inherited genetic disorders. The majority of PCCs/PGLs exhibit indolent behavior. However, according to their affiliation to molecular clusters based on underlying genetic aberrations, their tumorigenesis, location, clinical symptomatology, and potential to metastasize are heterogenous. Thus, PCCs/PGLs are often associated with diagnostic difficulties. In recent years, extensive research revealed a broad genetic background and multiple signaling pathways leading to tumor development. Along with this, the diagnostic and therapeutic options were also expanded. In this review, we focus on the current knowledge and recent advancements in the diagnosis and treatment of PCCs/PGLs with respect to the underlying gene alterations while also discussing future perspectives in this field.

Patients with germline SDHD pathogenic variants (encoding succinate dehydrogenase subunit D; ie, paraganglioma 1 syndrome) are predominantly affected by head and neck paragangliomas, which, in almost 20% of patients, might coexist with paragangliomas arising from other locations (eg, adrenal medulla, para-aortic, cardiac or thoracic, and pelvic). Given the higher risk of tumour multifocality and bilaterality for phaeochromocytomas and paragangliomas (PPGLs) because of SDHD pathogenic variants than for their sporadic and other genotypic counterparts, the management of patients with SDHD PPGLs is clinically complex in terms of imaging, treatment, and management options. Furthermore, locally aggressive disease can be discovered at a young age or late in the disease course, which presents challenges in balancing surgical intervention with various medical and radiotherapeutic approaches. The axiom-first, do no harm-should always be considered and an initial period of observation (ie, watchful waiting) is often appropriate to characterise tumour behaviour in patients with these pathogenic variants. These patients should be referred to specialised high-volume medical centres. This consensus guideline aims to help physicians with the clinical decision-making process when caring for patients with SDHD PPGLs.