Clinical features and outcomes of metastatic pheochromocytoma treated by cytotoxic chemotherapy.

Cytotoxic chemotherapy, including cyclophosphamide, vincristine, and dacarbazine (CVD) therapy, is widely used to treat metastatic pheochromocytoma and paraganglioma. Because these diseases are rare, studies are needed to establish treatment strategies. This was a single-center and retrospective study to analyze the efficacy of chemotherapy for patients with metastatic pheochromocytoma and paraganglioma diagnosed in 1983-2020. Clinical characteristics, tumor volume response, biochemical response based on catecholamine level, overall survival, and progression-free survival were evaluated. Patients with a complete response or partial response in tumor volume or catecholamine level were classified as responders. Sixteen patients were administered chemotherapy for a median of 16.5 cycles (interquartile range, 10-42). The tumor volume response was classified as follows: partial response (N = 4), stable disease (N = 9), and progressive disease (N = 3) (disease control rate = 81%). The biochemical responses were as follows: complete response (N = 2), partial response (N = 5), no change (N = 3), and progressive disease (N = 1) (disease control rate = 91%). The 5-year survival rate was 50% (95% confidence interval [CI], 21-74%) and median overall survival was 4.4 years (95% CI, 2.4 years-not reached). Overall survival and progression-free survival between responders and nonresponders were not statistically different. One patient developed myelodysplastic syndrome during CVD therapy. In conclusion, chemotherapy achieved disease control among more than half of patients, although survival did not differ between responders and nonresponders. Further fundamental research and prospective trials are needed to analyze the efficacy of CVD therapy.

Emerging Treatments for Advanced/Metastatic Pheochromocytoma and Paraganglioma.

OPINION STATEMENT: The incidence of metastatic pheochromocytoma (PHEO) and paraganglioma (PGL) may occur in as many as 35% of patients particularly with PGL and even more frequently in those with specific mutations. Biochemical, morphological, and molecular markers have been investigated for use in the distinction of benign from malignant PHEO/PGL. PHEO/PGL metastasizes via hematogenous or lymphatic routes and shows differences based on mutational status. The most common sites of involvement in patients that have an SDHB mutation are the bone (78%), lungs (45%), lymph nodes (36%), and liver (35%). In patients with sporadic PHEO/PGL, the most common sites of metastasis are the bones (64%), lungs (47%), lymph nodes (36%), and liver (32%). Metastases may be present at presentation or may occur later. Metastases to the liver and lungs are associated with a shorter survival. Overall, the estimated 5-year survival rates are between 34 and 74%. Currently, treatments for metastatic PHEO/PGL are essentially palliative. Surgery is potentially curative; however, tumor dissemination limits the chance for a curative resection. When surgical intervention is not amenable, the therapeutic options include radiolabeled MIBG (Azedra®-iobenguane 131 was recently FDA-approved for patients > 12 years and older with iobenguane scan positive) or systemic chemotherapy with cyclophosphamide, vincristine, and dacarbazine (CVD) with an overall objective response rate (ORR) of less than 40%; however, it is not clear if the administration of CVD impacts overall survival, as nearly all patients develop progressive and ultimately fatal disease. Other treatment modalities under investigation include cytoreductive techniques, novel radiopharmaceuticals, chemotherapy, radiotherapy, immunotherapy, and experimental therapies. Here we are discussing emerging treatment for advanced/metastatic PHEO/PGL.

Preoperative 18F-FDG PET/CT in Pheochromocytomas and Paragangliomas Allows for Precision Surgery.

BACKGROUND: Fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) imaging is recommended in patients with metastatic pheochromocytoma (PC) and paraganglioma (PGL). There are no data on whether routine preoperative F-FDG PET/CT in all patients with PC/PGL impacts surgical management. OBJECTIVE: The aim of this study was to determine whether routine preoperative F-FDG PET/CT imaging affects the surgical management of patients with PC/PGLs. METHODS: We analyzed clinical, biochemical, genetic, and anatomic imaging data in 93 consecutive patients with PC/PGL who collectively underwent a total of 100 operations and who had preoperative F-FDG PET/CT imaging. RESULTS: Of 100 operations, preoperative F-FDG PET/CT showed additional lesions compared to anatomic imaging in 15 cases. These patients were more likely to undergo an open surgical approach (P < 0.05). Presence of genetic mutation, redo operations, sex, age, or tumor size had no significant association with finding additional lesions on F-FDG PET/CT. CONCLUSIONS: Additional lesions detected on preoperative F-FDG-PET/CT imaging have an impact on the surgical approach in patients with PC/PGLs. Therefore, surgeons should routinely obtain F-FDG-PET/CT imaging in patients with PC/PGL to allow for a more precise surgical intervention.

Orbital Pheochromocytoma Metastasis in 2 Patients With Known Pheochromocytoma.

Two patients with previously diagnosed pheochromocytoma presented with facial pain and ptosis. Imaging revealed orbital lesions. Both patients were referred for surgical evaluation of the orbital mass. Surgical excision was performed for both. Pathology confirmed metastatic pheochromocytoma. Pheochromocytomas commonly metastasize to bone, liver, and other tissues. Five cases of metastasis to orbital bone have been previously described. These 2 cases are unique in that the metastases were not hormonally active, presented soon after initial diagnosis, and were treated palliatively with surgical excision. Previous treatment of orbital bony metastasis used radiotherapy. These cases demonstrate that surgical resection is a viable treatment option in these situations. Orbital metastasis of pheochromocytomas should be considered with the appropriate clinical presentation. These are the first documented cases of intraorbital metastasis, separate from the bony walls. Previously, orbital bony wall metastases were treated with radiation. Surgical excision is a viable option for treatment of such metastases.Orbital involvement should be considered in patients with systemic disease presenting with new ocular findings.

Metastatic phaeochromocytoma in a 23-year-old woman with an unclassified variant in the von Hippel Lindau disease gene: how can the pathogenicity of this variant be determined?

A 23-year-old woman with metastatic phaeochromocytoma was found to have a previously unclassified variant in the von Hippel Lindau disease gene (c.361G>C). We use this case to highlight the issue of unclassified single nucleotide variants and the approaches to help predict whether they are disease causing or neutral. With increasing use of genetic testing, and widespread clinical use of next-generation sequencing around the corner, this issue is likely to become more prominent.

Metastatic pheochromocytoma and paraganglioma.

BACKGROUND: Metastatic pheochromocytomas (PCs) and paragangliomas (PGLs) are rare neuroendocrine tumours with a strong genetic background. DESIGN: We searched the PubMed database through February 2015 to identify studies characterizing metastatic PCs/PGLs as well as currently established and evolving therapies. RESULTS: Large size tumours (> 5 cm), PASS score > 6 and Ki-67 labelling index > 3% are the most robust indices of metastatic PCs/PGLs albeit with great variability. Germline succinate dehydrogenase complex, subunit B (SDHB) mutation constitutes the main reliable molecular predictor of malignancy. Plasma and urinary methoxytyramine are the biochemical markers characterizing metastatic PCs/PGLs along with evolving molecular markers such as miRNAs and SNAIL. Conventional imaging is used for tumour localization, whereas (18)F-FDG-PET for staging of metastatic PCs/PGLs especially those related to SDHB gene mutations. In addition, (68)Ga-DOTATATE PET/CT is emerging as a highly sensitive alternative. Surgery remains the gold standard treatment in reducing tumour bulk and/or controlling the clinical syndrome. Treatment with (131)I-MIBG or radiolabelled somatostatin analogues is considered for unresectable disease. Conventional chemotherapy is reserved for more advanced and refractory to other therapies disease although new schemes are currently evolving. Recent genetic studies have highlighted a number of pathways involved in PCs/PGLs pathogenesis directing towards the use of targeted therapies which have still to be validated in clinical practice. CONCLUSIONS: Metastatic PCs/PGLs remain an orphan disease that is only curable by surgery. However, advances in genomic analyses have improved the pathogenesis of these tumours and may lead to effective and more personalized treatments in the near future.

Clinical course and prognostic factors in patients with malignant pheochromocytoma and paraganglioma: A single institution experience.

OBJECTIVES: Malignant pheochromocytoma (PCC)/paraganglioma (PG) are rare neuroendocrine malignancies, and their clinical courses and prognoses are not well understood. This study aimed to evaluate prognostic factors associated with the survival of malignant PCC/PG. METHODS: This retrospective study reviewed 299 patients with PCC and 46 with PG treated between 1997 and 2013 at our single tertiary hospital. Malignant PCC/PG was defined as the presence of distant metastasis or recurrence at sites where neuroendocrine tissue is normally not present. RESULTS: Twenty-seven patients (9%) were confirmed with malignant PCC and six patients (13%) with malignant PG. Twenty-seven patients (82%) had distant metastases, nine patients (27%) presented with a metastasis at the initial diagnosis, whilst 24 patients (73%) were diagnosed with malignant PCC/PG during follow-up (median, 4.3 year). The median survival was 7.2 years, and the 5 year survival rate was 75.4%. Older age (>45 years), larger tumor size (>6 cm), synchronous metastasis, and absence of surgical excision were associated with poor survival by univariate analysis. By multivariate analysis, older age (HR = 4.3, P = 0.02) and synchronous metastasis (HR = 4.3, P = 0.01) were significantly associated with a poor prognosis. CONCLUSIONS: Patients with malignant PCC/PG have diverse clinical courses. Poor survival was independently associated with older age and synchronous metastasis.

Patterns of Use and Short-Term Outcomes of Minimally Invasive Surgery for Malignant Pheochromocytoma: A Population-Level Study.

BACKGROUND: Malignant pheochromocytoma is rare, and there is a scarcity of data on the use of minimally invasive surgery (MIS) for treatment. The aims of this study were to analyze patterns of use of MIS for malignant pheochromocytoma in the U.S. and compare short-term outcomes to those of open adrenalectomy. METHODS: Patients with malignant pheochromocytoma undergoing MIS, including laparoscopy, robotic assisted, laparoscopy converted to open, or open adrenalectomy, were culled from the National Cancer Database, from 1998 to 2011. Data were examined using simple summary statistics, Χ2 and student's t tests, Mann-Whitney test, and logistic regression. RESULTS: A total of 36 MIS and 67 open adrenalectomies were identified in 2010-2011. No significant differences were observed between the two treatment groups in demographic characteristics or comorbidities. Preoperative diagnosis of malignancy was made in 52.8% of MIS and 48.5% of open patients (p=NS). MIS and open adrenalectomies did not differ with respect to lymph node metastases, vascular invasion, extra-adrenal-extension, and distant metastases (all p=NS). MIS tended to more often be used to perform partial adrenalectomy (38.9 vs. 20.4% open, p=0.061); surgical margins, 30-day readmission and mortality rates were similar to open adrenalectomy (all p=NS). Tumors removed via MIS were smaller (48.7 vs. 73.3 mm open, p=0.003) and associated with a shorter length of stay. CONCLUSIONS: A significant proportion of patients with malignant pheochromocytomas underwent MIS, with short-term outcomes which are comparable to those of open surgery. Further studies focused on long-term survival and recurrence are needed to assess the role of MIS in the management of these rare tumors.

[Hypertension, catecholamine hypersecretion and potential for metastasis: recent progress in the pathophysiology and genetics of pheochromocytoma and paraganglioma]. / Statut tensionnel, phénotype sécrétoire et potentiel métastatique chez les patients porteurs de phéochro- mocytome ou de paragangliome : données génétiques et physio-pathologiques récentes.

Pheochromocytomas and paragangliomas are catecholamine-secreting tumors usually associated with arterial hypertension. They can contribute to acute cardiovascular events. Ten to 15 percent of tumors are metastatic. Autosomal dominant gene alterations are present in more than a third of cases. The secretory phenotype and the risk of malignancy are driven by the presence of gene mutations, specifically in the subunits of succinate dehydrogenase. Recent advances in genomics have clinical implications for family screening, biological follow-up, prediction of the risk of recurrence, and therapeutic options in cases with malignant recurrence.

SDHB mutations are associated with response to temozolomide in patients with metastatic pheochromocytoma or paraganglioma.

Cyclophosphamide-dacarbazine-vincristine regimen is recommended for the treatment of malignant pheochromocytoma and paraganglioma (MPP); however, dacarbazine is the only recognized active drug in neuroendocrine tumours. We investigated the therapeutic benefit of temozolomide (TMZ), an oral alternative to dacarbazine, in patients with MPP. This is a retrospective study of consecutive patients with documented progressive MPP. We examined the correlation between Succinate dehydrogenase B (SDHB) mutation and O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation and MGMT expression in the French nation-wide independent cohort of 190 pheochromocytomas or paragangliomas (PP). Progression-free survival (PFS) according to RECIST 1.1 and PERCIST 1.0 criteria was the primary end point. Fifteen consecutive patients with MPP were enrolled; ten (67%) carried a mutation in SDHB. The mean dose intensity of TMZ was 172 mg/m(2) /d for 5 days every 28 days. Median PFS was 13.3 months after a median follow-up of 35 months. There were five partial responses (33%), seven stable (47%) and three progressive diseases (20%). Grade 3 toxicities were lymphopenia in two patients and hypertension in one. Partial responses were observed only in patients with mutation in SDHB. MGMT immunohistochemistry was negative in tumour samples from four patients who responded to treatment. SDHB germline mutation was associated with hypermethylation of the MGMT promoter and low expression of MGMT in 190 samples of the French nation-wide independent cohort. This study demonstrates that TMZ is an effective antitumour agent in patients with SDHB-related MPP. The silencing of MGMT expression as a consequence of MGMT promoter hypermethylation in SDHB-mutated tumours may explain this finding.

[Resistant arterial hypertension and a prominent sternum in a 77-year-old woman]. / Therapierefraktäre arterielle Hypertonie und prominentes Sternum bei einer 77-jährigen Patientin.

The case of a 77-year-old woman who was admitted with resistant arterial hypertension is reported. In view of a history of pheochromocytoma 2 years ago, catecholamine levels were examined and found to be elevated; in addition, MIBG scintigraphy showed a positive area in the anterior mediastinum. Computer tomography showed a tumor in the sternum. Histology confirmed metastasis from the pheochromocytoma, and the corpus was removed surgically. Currently, the patient is without any evidence of relapse.

Treatment of metastatic paraganglioma: experience of a single center.

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

Mortality associated with phaeochromocytoma.

Two major categories of mortality are distinguished in patients with phaeochromocytoma. First, the effects of excessive circulating catecholamines may result in lethal complications if the disease is not diagnosed and/or treated timely. The second category of mortality is related to development of metastatic disease or other neoplasms. Improvements in disease recognition and diagnosis over the past few decades have reduced mortality from undiagnosed tumours. Nevertheless, many tumours remain unrecognised until they cause severe complications. Death resulting from unrecognised or untreated tumour is caused by cardiovascular complications. There are also numerous drugs and diagnostic or therapeutic manipulations that can cause fatal complications in patients with phaeochromocytoma. Previously it has been reported that operative mortality was as high as 50% in unprepared patients with phaeochromocytoma who were operated and in whom the diagnosis was unsuspected. Today mortality during surgery in medically prepared patients with the tumour is minimal. Phaeochromocytomas may be malignant at presentation or metastases may develop later, but both scenarios are associated with a potentially lethal outcome. Patients with phaeochromocytoma run an increased risk to develop other tumours, resulting in an increased mortality risk compared to the general population. Phaeochromocytoma during pregnancy represents a condition with potentially high maternal and foetal mortality. However, today phaeochromocytoma in pregnancy is recognised earlier and in conjunction with improved medical management, maternal mortality has decreased to less than 5%.

Current and future therapeutic approaches for metastatic pheochromocytoma and paraganglioma: focus on SDHB tumors.

As a result of intense genetic studies of families with specific mutations, the road to better therapeutic intervention for pheochromocytoma (PHEOs) and parangangliomas (PGLs) has more recently become populated with several promising molecular targets. Consequently a change in paradigm from a previous view on nonspecific therapy has shifted towards more selective molecular targeted therapies. In particular, malignant PHEOs/PGLs, more specifically the tumors that result from mutations in succinate dehydrogenase subunit B (SDHB), are a clear concern, and novel therapies should be developed to address this problem. Here we summarize current and future therapeutic approaches.

Proteinuria in metastatic pheochromocytoma is associated with an increased risk of Acute Respiratory Distress Syndrome, spontaneously or after therapy with 131I-meta-iodobenzylguanidine (131I-MIBG).

Acute Respiratory Distress Syndrome (ARDS) has been reported rarely in pheochromocytoma, occurring spontaneously or after therapy with 131I-meta-iodobenzylguanidine (131I-MIBG). Our objective was to determine whether proteinuria is associated with an increased risk of ARDS. This was a retrospective analysis of a prospective cohort study of 64 patients with metastatic pheochromocytoma or paraganglioma treated with 131I-MIBG on institutional protocols. Proteinuria was defined as at least one urinalysis positive for at least trace protein within 1 month prior to 131I-MIBG or within 1 month prior to spontaneous ARDS. Proportions were compared using Fisher's exact test. Urinalyses within the defined time period were available for 48 patients, 8 of whom had proteinuria. Of the 8 patients with proteinuria, 5 developed ARDS: 3 within 10 days following 131I-MIBG, two 6 months following 131I-MIBG. Both patients who developed ARDS 6 months after 131I-MIBG had proteinuria within 1 month before apparently spontaneous ARDS. None of the 40 patients whose urinalyses were all negative for protein developed ARDS. None of the 16 patients with missing urinalyses developed ARDS. Patients with antecedent proteinuria were more likely to develop ARDS than those without proteinuria (63% vs. 0%; p<0.0001). The following variables were not significantly associated with ARDS: 131I-MIBG activities administered, number of 131I-MIBG administrations, age, hypertension, or secretion of catecholamines or metanephrines. In patients with metastatic pheochromocytoma or paraganglioma, proteinuria is associated with ARDS and urine protein should be examined prior to administering 131I-MIBG.

Malignant pheochromocytoma: new malignancy criteria.

PURPOSE: The pathological diagnosis of malignancy in pheochromocytomas remains a controversial issue. According to the WHO, malignancy is defined in the presence of metastasis. Multiparameter scoring systems such as PASS (Pheochromocytoma of Adrenal gland Scaled Score) have been used but remain controversial. The aim of this study was to search for new immunohistologic elements allowing determination of pheochromocytoma malignancy. METHODS: Among 53 patients operated for pheochromocytoma between 1993 and 2009, we selected pheochromocytomas with proven metastasis, seven cases in group 1 (G1) and paired two others groups: group 2 (G2), patients who had "benign" pheochromocytoma with PASS ≥4 and group 3 (G3), patients who had "benign" pheochromocytoma with PASS <4. We retrospectively analysed PASS criteria, size, weight, tumour necrosis, Ki-67 and pS100 staining. RESULTS: The size and weight of the lesion were directly and significantly correlated to malignancy in all three groups: respectively 9.7 cm and 292.0 g (G1), 6.2 cm and 83.8 g (G2) and 3.8 cm and 37.1 g (G3) (p < 0.005 for both). Tumour necrosis (TN) was present in all G1 (p < 0.005) and respectively at 0% and 37.5% in G2 and G3. Ki-67 is directly correlated to presence of TN (p < 0.005) and malignancy (G1 14.1%, G2 1.8%, G3 2.6%; p < 0.001). All G1 had a Ki-67 index >4%, although one G3 presented an 11% Ki-67 index. There was an inverse statistically significant correlation between the three groups in staining using pS100 (p < 0.01). CONCLUSIONS: Size and weight of the pheochromocytoma are directly related to PASS and malignancy. The presence of tumour necrosis, Ki-67 index >4% and pS100 absence impose a close histopathological evaluation and follow-up with regard to cases presenting a high risk of malignancy/recurrence.

Minimally invasive treatment of metastatic pheochromocytoma and paraganglioma: efficacy and safety of radiofrequency ablation and cryoablation therapy.

PURPOSE: To evaluate the safety and efficacy of percutaneous ablation methods for the treatment of metastatic pheochromocytomas (PCCs) and paragangliomas (PGLs). MATERIALS AND METHODS: From May 2001 to November 2009, 10 patients (mean age 45 years) with metastatic PCCs and PGLs were identified and treated with percutaneous ablation. All patients were given appropriate medication before the ablation procedure. Vital signs were monitored before, during, and after the procedure. There were 47 tumor ablations performed using radiofrequency (RF) ablation, cryoablation, or ethanol injection as determined by tumor location. RESULTS: In all patients, all metastatic lesions amendable to percutaneous ablation were treated; for 2 of 10 patients, all known metastases were treated. Successful ablation without evidence of recurrence was achieved in 56% (15 of 27) of primarily treated lesions in patients with available follow-up imaging. The time to disease progression after ablation was 7.2 months ± 4.0. Amelioration of breakthrough hypertensive symptoms or metastasis-related pain was achieved in two of two patients and four of four patients, respectively, at clinical follow-up. Comparison of intra-arterial blood pressure before, during, and after the procedures showed statistically significant differences in these median blood pressures (P = .004-.05). Major complications occurred after 2 of 18 (11%) ablation sessions, including one unplanned increase in level of patient care and one periprocedural death from complications related to bowel perforation. CONCLUSIONS: Local control of metastatic PCCs and PGLs with percutaneous ablation can play an important role in disease management when the lesions are unresectable surgically, and there is potential for prolongation of patient function or amelioration of metastasis-related symptoms.

Metastatic Pheochromocytomas and Abdominal Paragangliomas.

CONTEXT: Pheochromocytomas and paragangliomas (PPGLs) are believed to harbor malignant potential; about 10% to 15% of pheochromocytomas and up to 50% of abdominal paragangliomas will exhibit metastatic behavior. EVIDENCE ACQUISITION: Extensive searches in the PubMed database with various combinations of the key words pheochromocytoma, paraganglioma, metastatic, malignant, diagnosis, pathology, genetic, and treatment were the basis for the present review. DATA SYNTHESIS: To pinpoint metastatic potential in PPGLs is difficult, but nevertheless crucial for the individual patient to receive tailor-made follow-up and adjuvant treatment following primary surgery. A combination of histological workup and molecular predictive markers can possibly aid the clinicians in this aspect. Most patients with PPGLs have localized disease and may be cured by surgery. Plasma metanephrines are the main biochemical tests. Genetic testing is important, both for counseling and prognostic estimation. Apart from computed tomography and magnetic resonance imaging, molecular imaging using 68Ga-DOTATOC/DOTATATE should be performed. 123I-MIBG scintigraphy may be performed to determine whether 131I-MIBG therapy is a possible option. As first-line treatment in patients with metastatic disease, 177Lu-DOTATATE or 131I-MIBG is recommended, depending on which shows best expression. In patients with very low proliferative activity, watch-and-wait or primary treatment with long-acting somatostatin analogues may be considered. As second-line treatment, or first-line in patients with high proliferative rate, chemotherapy with temozolomide or cyclophosphamide + vincristine + dacarbazine is the therapy of choice. Other therapies, including sunitinib, cabozantinib, everolimus, and PD-1/PDL-1 inhibitors, have shown modest effect. CONCLUSIONS: Metastatic PPGLs need individualized management and should always be discussed in specialized and interdisciplinary tumor boards. Further studies and newer treatment modalities are urgently needed.