Metastatic Pheochromocytoma Research Articles

Anesthesia and Outcome of 33 Surgeries in 24 Multiple Endocrine Neoplasia Type 2A (MEN2A) Patients: A National Rare Disease Center's Experience.

BackgroundMultiple endocrine neoplasia type 2A (MEN2A) is a rare syndrome that presents as medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Experience is lacking in the anesthetic management of patients with this syndrome, particularly in those who present with pheochromocytoma receiving nonpheochromocytoma resection. We aimed to share our experience with the anesthetic management of MEN2A patients.MethodWe retrospectively enrolled 24 MEN2A patients who had received different types of surgery at Peking Union Medical College Hospital from January 1, 2015, to December 31, 2021. All the medical records were reviewed and analyzed.ResultIn total, 33 surgeries were performed in 24 MEN2A patients, with 20 surgeries comprising pheochromocytoma resection in 17 patients. Most of these patients who had received pheochromocytoma resection had typical hemodynamic changes during surgery and anesthesia. Regarding the other 13 nonpheochromocytoma resections in 13 patients, 10 were performed in patients without pheochromocytoma, and 3 surgeries were performed with either functional primary (1, bilateral tumor whose patient refused adrenalectomy) or metastatic pheochromocytoma (2, unresectable and malign tumors developed years after bilateral adrenalectomy). Regarding the latter 3 patients, 1 showed hypertension and tachycardia during anesthesia induction, 1 showed tachycardia during surgery and the other showed stability during surgery. Patients who had received pheochromocytoma resection (n=17) required longer postoperative hospital stays than those who had received nonpheochromocytoma resection without pheochromocytoma (n=10) (5.8 ± 1.8 vs. 4.3 ± 1.6; P = 0.031).ConclusionsWhenever MEN2A patients are diagnosed with pheochromocytoma, surgical resection of the pheochromocytoma remains the primary choice for MEN2A treatment. Nonpheochromocytoma surgeries performed with existing pheochromocytoma could be risky and require full caution and preparation.

Anlotinib for the treatment of locally advanced or metastatic pheochromocytoma and paraganglioma: A retrospective study.

e16209 Background: Pheochromocytomas (PCC) and paragangliomas (PGL) are rare hyper-vascular neuroendocrine tumors derived from the adrenal medulla and paraganglia, respectively. In previous studies, the overall survival at 5 years for patients (pts) with metastatic disease was only 50% to 60% after the diagnosis of metastases. Anlotinib is a novel multikinase inhibitor targeting VEGFR, PDGFR, FGFR, and c-Kit. This study investigated the efficacy and safety of anlotinib monotherapy or in combination with other therapies in treating locally advanced or metastatic (LA/M) PCC and PGL. Methods: Pts with histologically or cytologically confirmed unresectable or progressive LA/M PCC or LA/M PGL were enrolled from March 2020 to October 2021. The inclusion criteria contained: (a) age 18 or older, (b) ECOG performance status 0–2, (c) adequate organ and marrow function. Eligible pts received anlotinib monotherapy or in combination with peptide receptor radionuclide therapy (PRRT) or 131I-MIBG. Anotinib was given orally 12 mg once daily (d1-d14, q3w) until the disease progression or the intolerable toxicities. Tumor response was assessed according to RECIST1.1. Results: 35 pts were enrolled (Table) and 25 were assessed for tumor response. Among them, 17 received anlotinib alone, others were treated with the combination regimen, including 6 with PRRT, and 2 with 131I-MIBG respectively. At the data cut-off date on January 15th, 2022, 4 pts progressed and 1 died. The median duration of treatment was 8.5 months. 10 pts (40%) achieved partial response (PR) and the stable disease (SD) was observed in 13 pts (52%). The objective response rate (ORR) for 25 pts was 40% and the disease control rate (DCR) was 92%. For pts with PCC and PGL, the ORR was 33.3% and 46.2%, respectively. All pts were assessed for safety. The most common adverse events (AEs) included: malaise (23 pts, 65.7%), palmar-plantar erythrodysesthesia syndrome (PPE) (23 pts, 65.7%), hypertension (22 pts, 62.9%) and oropharyngeal pain (17 pts, 48.6%). The most common grade 3 or worse AEs were hypertension (15 pts) and PPE (4 pts), which were claimed tolerable by the pts. Conclusions: This single-center retrospective study indicated that anlotinib monotherapy or in combination with radionuclide therapy showed promising efficacy and favourable safety profile in the treatment of LA/M PCC and PGL, which is worthy of further exploration.[Table: see text]

A phase 2 study of anlotinib in patients with metastatic pheochromocytoma/paraganglioma.

e15000 Background: Metastatic pheochromocytoma / paraganglioma (MPP) are rare while the prognosis was poor and the efficacy for current therapy was unsatisfactory. Anlotinib is a multikinase inhibitor targeting tumor angiogenesis and growth. Currently, there is no study evaluating the efficacy and safety of anlotinib in MPP pts. Methods: This is a prospective, single-arm phase 2 trial (NCT 04860700). Pts with histologically or radiologically confirmed MPP were enrolled. Main other inclusion criteria were 18-75 years old and ECOG PS 0-2. Anlotinib (8-12mg, QD) were given orally from d1 to d14 every 21 days until disease progression or intolerable toxicities. The primary endpoint was objective response rate (ORR) per RECIST 1.1. Secondary endpoints included biochemical (catecholamine levels) response rate (BRR), progression-free survival (PFS) and safety. Results: 10 pts with MPP were enrolled and tumor response were evaluated in 6 patients. All these 6 patients had objective radiological evidence of progression within 6 months before enrollment. Tumor shrinkage was observed in 4 pts, 1 achieved partial response (PR) and 3 achieved stable disease (SD). The ORR was 16.7% (1/6). For 1 patient (p-1) with no measurable lesions, the pathological lymph nodes shrunk obviously and the rapid progression of bone metastatic lesion was well controlled. Among all 6 pts, catecholamine levels were obviously decreased in 4 pts, achieving a BRR of 67%. 1 patient who developed blindness at right eye caused by the progression of intracranial metastasis after chemotherapy had recovered the vision after anlotinib treatment. At the data cutoff date on February 1st, 2022, 1 patient terminated anlotinib since obvious elevation of catecholamine level and others were still in treatment with no radiographic disease progression. The median treatment duration was 7.5 cycles. The details of efficacy result were listed in table below. Overall, treatment of anlotinib blocked the rapid disease progression and achieved a durable disease control. The most common treatment-related adverse event (TRAE) was hypertension (5/6), which was well controlled, other TRAEs occurred in > 1 pts included grade 1 or 2 proteinuria (2/6) and palmar-plantar erythrodysesthesia syndrome (2/6). Conclusions: The preliminary results of this study indicated that anlotinib is a potential choice for the treatment of MPP with the high ability on disease control and well tolerability. Clinical trial information: NCT04860700. [Table: see text]

Preclinical evaluation of targeted therapies in Sdhb-mutated tumors.

Therapies for metastatic SDHB-dependent pheochromocytoma and paraganglioma (PPGL) are limited and poorly efficient. New targeted therapies and identification of early non-invasive biomarkers of response are thus urgently needed for these patients. We characterized an in vivo allograft model of spontaneously immortalized murine chromaffin cells (imCC) with inactivation of the Sdhb gene by dynamic contrast-enhanced MRI (DCE-MRI) and 18FDG-PET. We evaluated the response to several therapies: IACS-010759 (mitochondrial respiratory chain complex I inhibitor), sunitinib (tyrosine kinase inhibitor with anti-angiogenic activity), talazoparib (poly ADP ribose polymerase (PARP) inhibitor) combined or not to temozolomide (alkylating agent), pharmacological inhibitors of HIF2a (PT2385 and PT2977 (belzutifan)) and molecular inactivation of HIF2a (imCC Sdhb-/- shHIF2a). Multimodal imaging was performed, including magnetic resonance spectroscopy (1H-MRS) to monitor the level of succinate in vivo. The allografted model of Sdhb-/- imCC reflected SDHB-deficient tumors, with increased angiogenesis and a particular avidity for 18FDG. After 14 days of treatment, IACS-010759, sunitinib and talazoparib at high doses allowed a significant reduction of the tumor volumes. In contrast to the tumor growth inhibition observed in Sdhb-/- shHIF2a imCC tumors, pharmacological inhibitors of HIF2a (PT2385 and belzutifan) showed no antitumor action in this model, alone or in combination with sunitinib. 1H-MRS, but not DCE-MRI, enabled the monitoring response to sunitinib, which was the best treatment in this study, promoting a decrease in succinate levels detected in vivo. This study paves the way for new therapeutic options and reveals a potential new early biomarker of response to treatment in SDHB-dependent PPGL.

Metastatic pheochromocytomas and paragangliomas: where are we?

Pheochromocytomas and paragangliomas (PPGLs) can metastasize in approximately 15-20% of cases. This review discusses the available evidence on the biology and treatment of metastatic PPGLs. Chemotherapy is the first-line treatment option for this evolving and symptomatic disease. In patients with high MIBG uptake and positive PETGa-68, radiometabolic treatment may be considered. The efficacy of sunitinib has been shown in observational studies, and pembrolizumab has been evaluated in phase II clinical studies, while other agents investigated in this setting are anti-angiogenic drugs cabozantinib, dovitinib, axitinib and lenvatinib. As these agents' efficacy and safety data, alone or in combination, are scant and based on few treated patients, enrollment in clinical trials is mandatory. Future therapeutic options may be represented by DNA repair system inhibitors (such as olaparib), HIF2 inhibitors and immunotherapy.

Long-term follow-up of patients undergoing laparoscopic surgery for phaeochromocytoma.

IntroductionPhaeochromocytomas are rare tumours with a recurrence after open surgery ranging between 6–23 per cent. Long-term follow-up studies after laparoscopic surgery for phaeochromocytoma are lacking. The aim of this study was to look at the long-term oncological outcome of a consecutive series of patients from a single centre undergoing laparoscopic surgery for a phaeochromocytoma.MethodsDemographic data on all patients with an adrenal tumour or paraganglioma were prospectively kept on a database between September 1999 and December 2017. Electronic hospital records, including imaging from a national linked archiving and communication system, were reviewed for patients with a phaeochromocytoma in November 2021.ResultsDuring the study interval 135 patients with a phaeochromocytoma were operated on in the unit, of which 118 (87.4 per cent) were attempted laparoscopically. Five (4.2 per cent) were converted to open surgery, whereas 117 had a potentially curative operation. There was no peri- or postoperative mortality. At a median follow-up of 10 (interquartile range 6–12.9) years, only 3 (2.6 per cent) patients died from metastatic phaeochromocytoma. One further patient developed lymph node metastases, which were removed at open surgery. No patient had a local recurrence and the only significant predictor of recurrence was the presence of lymph node metastases (P < 0.001). Two patients developed a contralateral adrenal phaeochromocytoma, while one of these also had a paraganglioma. The Kaplan–Meier estimate of phaeochromocytoma-free survival was 96 per cent (95 per cent c.i. 92.2 to 98.8) at 5 years and 92 per cent (95 per cent c.i. 86.7 to 97.3) at 10 years.ConclusionThis study demonstrates that long-term oncological outcomes of laparoscopic surgery for patients with a phaeochromocytoma are at least as good as that with an open operation.

Determinants of disease-specific survival in patients with and without metastatic pheochromocytoma and paraganglioma

BackgroundPheochromocytomas and paragangliomas (PPGLs) have a heterogeneous prognosis, the basis of which remains unclear. We, therefore, assessed disease-specific survival (DSS) and potential predictors of progressive disease in patients with PPGLs and head/neck paragangliomas (HNPGLs) according to the presence or absence of metastases. MethodsThis retrospective study included 582 patients with PPGLs and 57 with HNPGLs. DSS was assessed according to age, location and size of tumours, recurrent/metastatic disease, genetics, plasma metanephrines and methoxytyramine. ResultsAmong all patients with PPGLs, multivariable analysis indicated that apart from older age (HR = 5.4, CI = 2.93–10.29, P < 0.0001) and presence of metastases (HR = 4.8, CI = 2.41–9.94, P < 0.0001), shorter DSS was also associated with extra-adrenal tumour location (HR = 2.6, CI = 1.32–5.23, P = 0.0007) and higher plasma methoxytyramine (HR = 1.8, CI = 1.11–2.85, P = 0.0170) and normetanephrine (HR = 1.8, CI = 1.12–2.91, P = 0.0160). Among patients with HNPGLs, those with metastases presented with longer DSS compared to patients with metastatic PPGLs (33.4 versus 20.2 years, P < 0.0001) and only plasma methoxytyramine (HR = 13, CI = 1.35–148, P = 0.0380) was an independent predictor of DSS. For patients with metastatic PPGLs, multivariable analysis revealed that apart from older age (HR = 6.2, CI = 3.20–12.20, P < 0.0001), shorter DSS was associated with the presence of synchronous metastases (HR = 4.9, CI = 2.78–8.80, P < 0.0001), higher plasma methoxytyramine (HR = 2.4, CI = 1.44–4.14, P = 0.0010) and extensive metastatic burden (HR = 2.1, CI = 1.07–3.79, P = 0.0290). ConclusionsDSS among patients with PPGLs/HNPGLs relates to several presentations of the disease that may provide prognostic markers. In particular, the independent associations of higher methoxytyramine with shorter DSS in patients with HNPGLs and metastatic PPGLs suggest the utility of this biomarker to guide individualized management and follow-up strategies in affected patients.

Surgical Treatment of Spinal Metastatic Pheochromocytoma and Paraganglioma: A Single Institutional Cohort of 18 Patients.

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 39months, and the overall survival rate of 1year 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.

Major intraoperative bleeding and drastic change in circulatory dynamics in a pregnant patient with metastatic pheochromocytoma: a case report

BackgroundMetastatic pheochromocytoma in the spine is a very rare complication during pregnancy. We report anesthesia in a pregnant woman for resection of an undiagnosed spinal tumor, accompanied by remarkable hemodynamic changes and massive bleeding.Case presentationA 33-year-old woman at 17 weeks of gestation presented with the rapid progress of bilateral lower leg paralysis. A diagnosis of spinal tumor was made, and surgical resection was planned. Although the surgery was suspended because of remarkable hemodynamic changes and massive bleeding, fetal heart rate was stable. Postoperative examination revealed pheochromocytoma in the urinary bladder as a primary lesion with spinal metastasis.ConclusionAlthough spinal pheochromocytoma is extremely rare in pregnant women, it should be suspected when abnormal hypertension is observed with accompanying neurological deficits. Preservation of maternal circulation and uteroplacental blood flow should be the first priority during anesthesia.

Metastatic Extra-Adrenal Pheochromocytoma with Single Kidney and Renal Compromise: A Case Report of Excellent Response, Tolerability, and Outcome to a Modified Regimen of 131I-mIBG, and Decision-Making between 131I-mIBG Therapy and PRRT

AbstractDetermining the choice and the goal is key element for decision-making of a systemic radionuclide therapy. They should be clearly defined in deciding and individualizing the dose and regimen. For iodine-131 metaiodobenzylguanidine (131I-mIBG) therapy, the important considerations during dose fractionation include disease burden, tumor biology, functional symptoms, and associated comorbidities, all of which are important determinants for the intent and course of treatment. Herein, we present the case of a 67-year-old elderly female with highly functional metastatic recurrent extra-adrenal pheochromocytoma (presenting 42 years after the primary surgery and 32 years following excision of pararenal recurrence) with multiple comorbidities including single kidney and borderline renal compromise, treated successfully with a relatively lower dose of 131I-mIBG (cumulative dose of 22.2 GBq in four cycles with a mean dose of 5.7 GBq per therapy cycle). The excellent tumor burden reduction, hormonal tumor marker response, and most importantly asymptomatic status could be achieved with the administered dose. On follow-up, none of the pretherapeutic parameters (including renal function) showed any further derangement compared with the baseline during next 24 months following the treatment. All cycles were well tolerated with only reversible hematological toxicity that normalized without any active intervention. The report is intended to provide some guidance for future therapeutic regimens.

Endocrine and Neuroendocrine Tumors Special Issue-Checkpoint Inhibitors for Adrenocortical Carcinoma and Metastatic Pheochromocytoma and Paraganglioma: Do They Work?

Simple SummaryIn the past decade, the landscape of cancer treatment has radically changed after the introduction of immunotherapy. Adrenocortical carcinoma and metastatic pheochromocytoma/paraganglioma are rare cancers with limited responses to traditional cancer treatments. The use of immunotherapy against these cancers has yielded a few responses when used alone or in combination with other drugs. We reviewed the current literature to summarize the role of immunotherapy in these rare cancers.Adrenocortical cancers and metastatic pheochromocytomas are the most common malignancies originating in the adrenal glands. Metastatic paragangliomas are extra-adrenal tumors that share similar genetic and molecular profiles with metastatic pheochromocytomas and, subsequently, these tumors are studied together. Adrenocortical cancers and metastatic pheochromocytomas and paragangliomas are orphan diseases with limited therapeutic options worldwide. As in any other cancers, adrenocortical cancers and metastatic pheochromocytomas and paragangliomas avoid the immune system. Hypoxia-pseudohypoxia, activation of the PD-1/PD-L1 pathway, and/or microsatellite instability suggest that immunotherapy with checkpoint inhibitors could be a therapeutic option for patients with these tumors. The results of clinical trials with checkpoint inhibitors for adrenocortical carcinoma or metastatic pheochromocytoma or paraganglioma demonstrate limited benefits; nevertheless, these results also suggest interesting mechanisms that might enhance clinical responses to checkpoint inhibitors. These mechanisms include the normalization of tumor vasculature, modification of the hormonal environment, and vaccination with specific tumor antigens. Combinations of checkpoint inhibitors with classical therapies, such as chemotherapy, tyrosine kinase inhibitors, radiopharmaceuticals, and/or novel therapies, such as vaccines, should be evaluated in clinical trials.

New Directions in Treatment of Metastatic or Advanced Pheochromocytomas and Sympathetic Paragangliomas: an American, Contemporary, Pragmatic Approach.

Multiple therapies with novel mechanisms have been explored in clinical trials for the treatment of metastatic pheochromocytomas and paragangliomas. We review current and future therapies for this disease and provide guidance on how and when to prescribe them based on tumor progression, clinical manifestations, molecular features, and social factors. Approximately 60-70% of metastatic pheochromocytomas and paragangliomas express the noradrenaline transporter in their cell membranes. High specific activity iodine-131 metaiodobenzylguanidine has been recently approved by the US Food and Drug Administration for the treatment of metastatic pheochromocytomas and paragangliomas that express the noradrenaline transporter, in patients aged ≥ 12years. More than 90% of patients treated with this medication exhibit clinical benefits. However, other therapies with novel mechanisms of action are needed to help all patients with this disease. Treatment of metastatic pheochromocytomas and paragangliomas is recommended based on the severity of symptoms, the progression of the disease, and the patient's performance status. Currently available therapies include surgery; systemic chemotherapy with cyclophosphamide, vincristine, and dacarbazine, or with temozolomide; high specific activity iodine-131 metaiodobenzylguanidine; peptide receptor radionuclide therapy; immunotherapy; tyrosine kinase inhibitors; and hypoxia-inducible factor 2 alpha inhibitors. Financial and social factors such as health insurance coverage and disparities also impact current clinical practice in the USA.

Metastatic cluster 2-related pheochromocytoma/paraganglioma: a single-center experience and systematic review.

Risk of metastatic disease in the cluster 2-related pheochromocytoma/paraganglioma (PPGL) is low. In MEN2 patients, identification of origin of metastases from pheochromocytoma (PCC) or medullary thyroid carcinoma (MTC) is challenging as both are of neuroendocrine origin. We aim to describe our experience and perform a systematic review to assess prevalence, demographics, biochemistry, diagnostic evaluation, management, and predictors of cluster 2-related metastatic PPGL. Retrospective analysis of 3 cases from our cohort and 43 cases from world literature was done. For calculation of prevalence, all reported patients (n = 3063) of cluster 2 were included. We found that the risk of metastasis in cluster 2-related PPGL was 2.6% (2% in RET, 5% in NF1, 4.8% in TMEM127 and 16.7% in MAX variation). In metastatic PCC in MEN2, median age was 39 years, bilateral tumors were present in 71% and median tumor size was 9.7 cm (range 4–19) with 43.5% mortality. All patients had a primary tumor size ≥4 cm. Origin of primary tumor was diagnosed by histopathology of metastatic lesion in 11 (57.9%), 131I-MIBG scan in 6 (31.6%), and selective venous sampling and CT in 1 (5.3%) patient each. In subgroup of neurofibromatosis 1 (NF1), median age was 46 years (range 14–59) with median tumor size 6 cm and 57% mortality. To conclude, the risk of metastatic disease in cluster 2-related PPGL is low, being especially high in tumors with size ≥4 cm and associated with high mortality. One-third patients of NF1 with metastatic PPGL had presented in second decade of life. Long-term studies are needed to formulate management recommendations.

Special situations in pheochromocytomas and paragangliomas: pregnancy, metastatic disease, and cyanotic congenital heart diseases.

The aimof our study was to describe the epidemiology, diagnosis, and treatment of the most complex pheochromocytoma and paraganglioma (PGL) cases, including pheochromocytoma/PGL during pregnancy, in cyanotic congenital heart diseases (CCHDs), and metastatic pheochromocytoma. The English and Spanish literature was thoroughly evaluated searching for articles reporting clinical studies, case reports, or reviews of pheochromocytoma/PGL in pregnancy and in CCHD and metastatic pheochromocytoma/PGL. Particular settings in the diagnosis and management of pheochromocytoma and PGLs remain challenging. Those special situations include the diagnosis during pregnancy or in the context of CCHD since the typical clinical features of pheochromocytoma may be confounded with preeclampsia during pregnancy and with the complications commonly observed in CCHD. In addition, although some clinical and genetic features have been associated with higher risk of metastatic pheochromocytoma, the detection and prediction of the development of metastatic disease involve another complex situation that may require special hormonal determinations as plasmatic 3-methoxytyramine and nuclear medicine studies including 18FDG PET-CT or 18F-FDOPA PET-CT, among others. Furthermore, the selection of the most appropriate treatment in these situations, as well as the moment to carry it out, requires special care as limited evidence is available. This article reviews the epidemiology, diagnosis, and treatment of the pheochromocytoma/PGL during pregnancy, metastatic pheochromocytoma/PGL, and pheochromocytoma/PGL in CCHD. The diagnosis, and especially the treatment, of metastatic pheochromocytomas and pheochromocytoma/PGL during pregnancy and in CCHD is challenging. Thus, these cases should be management in reference centres by multidisciplinary teams specialized in the pheochromocytoma/PGL treatment.

Diagnostic Performance of 124I-Metaiodobenzylguanidine PET/CT in Patients with Pheochromocytoma.

123/131I-metaiodobenzylguanidine (MIBG) scintigraphy has shown a high specificity for imaging pheochromocytoma and paraganglioma, but with low sensitivity because of low spatial resolution. 124I-MIBG PET may be able to overcome this limitation and improve the staging of patients with (suspected) pheochromocytoma. Methods: We analyzed the sensitivity, specificity, and positive and negative predictive values of 124I-MIBG PET in 43 consecutive patients with suspected (recurrence of) pheochromocytoma using histopathologic (n = 25) and clinical validation (n = 18) as the standard of truth. Furthermore, we compared the detection rate of 124I-MIBG PET versus contrast-enhanced (CE) CT on a per-patient and per-lesion basis in 13 additional patients with known metastatic malignant pheochromocytoma. Results:124I-MIBG PET/CT was positive in 19 (44%) of 43 patients with suspected pheochromocytoma. The presence of pheochromocytoma was confirmed in 22 (51%) of 43. 124I-MIBG PET/CT sensitivity, specificity, and positive and negative predictive values were 86%, 100%, 100%, and 88%, respectively. 124I-MIBG PET was positive in 11 (85%) of 13 patients with malignant pheochromocytoma. Combined 124I-MIBG PET and CE CT detected 173 lesions, of which 166 (96%) and 118 (68%) were visible on 124I-MIBG PET and CE CT, respectively. Conclusion:124I-MIBG PET detects pheochromocytoma with high accuracy at initial staging and a high detection rate at restaging. Future assessment of 124I-MIBG PET for treatment guidance, including personalized 131I-MIBG therapy, is warranted.

Systemic Radiopharmaceutical Therapy of Pheochromocytoma and Paraganglioma.

Whereas benign pheochromocytomas and paragangliomas are often successfully cured by surgical resection, treatment of metastatic disease can be challenging in terms of both disease control and symptom control. Fortunately, several options are available, including chemotherapy, radiation therapy, and surgical debulking. Radiolabeled metaiodobenzylguanidine (MIBG) and somatostatin receptor imaging have laid the groundwork for use of these radiopharmaceuticals as theranostic agents. 131I-MIBG therapy of neuroendocrine tumors has a long history, and the recent approval of high-specific-activity 131I-MIBG for metastatic or inoperable pheochromocytoma or paraganglioma by the U.S. Food and Drug Administration has resulted in general availability of, and renewed interest in, this treatment. Although reports of peptide receptor radionuclide therapy of pheochromocytoma and paraganglioma with 90Y- or 177Lu-DOTA conjugated somatostatin analogs have appeared in the literature, the approval of 177Lu-DOTATATE in the United States and Europe, together with National Comprehensive Cancer Network guidelines suggesting its use in patients with metastatic or inoperable pheochromocytoma and paraganglioma, has resulted in renewed interest. These agents have shown evidence of efficacy as palliative treatments in patients with metastatic or inoperable pheochromocytoma or paraganglioma. In this continuing medical education article, we discuss the therapy of pheochromocytoma and paraganglioma with 131I-MIBG and 90Y- or 177Lu-DOTA-somatostatin analogs.

1120P The prognostic and predictive roles of Ki67 and functional imaging tests in patients (pts) with metastatic pheochromocytoma or paraganglioma (mPPGL) treated with chemotherapy

1120P The prognostic and predictive roles of Ki67 and functional imaging tests in patients (pts) with metastatic pheochromocytoma or paraganglioma (mPPGL) treated with chemotherapy

LncRNA expression and SDHB mutations in pheochromocytomas and paragangliomas

Although pheochromocytomas and paragangliomas (PPGLs) are usual low-grade neoplasms, the metastatic forms of these lesions are associated with high morbidity and mortality. Recent studies have discovered multiple aberrantly expressed long non-coding RNAs (lncRNAs) in cancers that may have regulatory roles in tumor pathogenesis and metastasis; however, the roles of some lncRNAs in PPGLs are still unknown. The expression levels of lncRNAs including metastasis-associated lung adenocarcinoma transcript (MALAT1), prostate cancer antigen 3 (PCA3), and HOX transcript antisense intergenic RNA (HOTAIR) in PPGLs were analyzed by in situ hybridization, using two tissue microarrays (TMAs). The pheochromocytoma (PCC) TMA consisted of normal adrenal medulla (N = 25), non-metastatic PCCs (N = 76) and metastatic PCCs (N = 5) while the paraganglioma (PGL) TMA had 73 non-metastatic PGLs and 5 metastatic PGLs. Immunohistochemical staining was performed on all samples with an anti-SDHB antibody. The correlations between lncRNA expression, loss of SDHB expression and clinical characteristics including tumor progression and disease prognosis were investigated. The expression levels of MALAT1 and PCA3 were significantly elevated (2.5–3.9 folds) in both non-metastatic and metastatic PCCs compared to normal adrenal medulla, although there were no significant differences between the non-metastatic and metastatic neoplasms. In contrast to non-metastatic PGLs, metastatic PGLs had significantly upregulated expression of MALAT1, PCA3, and HOTAIR. SDHB loss was more frequently observed in PGLs (25 of 78), especially in metastatic PGLs (5 of 5), compared to PCCs (2 of 81) and in 0 of 5 metastatic PCCs. Patients with SDHB loss, in contrast to SDHB retained, were younger at diagnosis, had higher rates of tumor recurrence, metastatic disease, and mortality. In addition, PGLs with SDHB loss had significantly increased expression of PCA3 compared to tumors with intact SDHB expression. Our findings suggest that specific lncRNAs may be involved in the SDHx signaling pathways in the tumorigenesis and in the development of PPGL.

Supportive Management of Patients with Advanced Pheochromocytomas and Paragangliomas Receiving PRRT.

Peptide receptor radionuclide therapy (PRRT) is used to treat patients with advanced malignant pheochromocytomas (PCCs) and paragangliomas (PGLs). Patients are at risk of a PRRT-induced catecholamine crisis, and standard guidelines regarding the prevention and management of infusion reactions are lacking. In this case series, the institutional experience of five sequential patients with metastatic PCCs and PGLs receiving PRRT on an outpatient basis is described, of which four had symptomatic tumors and three had a high burden of disease. All patients with symptomatic tumors were treated with preventive management prior to the initiation of PRRT, and no infusion reactions or catecholamine crises were documented. PRRT may be delivered safely on an outpatient basis for patients with metastatic PCCs and PGLs with the involvement of an interdisciplinary team.

Peptide receptor radionuclide therapy in patients with metastatic progressive pheochromocytoma and paraganglioma: long-term toxicity, efficacy and prognostic biomarker data of phase II clinical trials

BackgroundPheochromocytoma and paraganglioma (PPGL) have currently only limited treatment options available for patients in the metastatic phase (mPPGL) in either post-surgery or inoperable settings. However, these rare tumors overexpress somatostatin receptors and can thus be treated with peptide receptor radionuclide therapy (PRRT). We present data about our 10-year experience treating 46 consecutive mPPGL patients with 90Y-DOTATOC or 177Lu-DOTATATE.Patients and methodsAll patients (20 men and 26 women, median age 52 years) showed positive scintigraphic imaging at 111In-octreotide or 68Ga-DOTATOC positron emission tomography/computed tomography (PET/CT). 90Y-DOTATOC was administered in 12 patients, with cumulative dosages ranging from 7.4 to 11 GBq, while 34 patients received 18.5 or 27.5GBq of 177Lu-DOTATATE. We used Southwest Oncology Group Response Evaluation Criteria in Solid Tumors criteria to evaluate treatment efficacy and Common Terminology Criteria for Adverse Events criteria to assess toxicity. The prognostic role of primary tumor site, hormone secretion, succinate dehydrogenase (SDHx) mutation, and metastatic involvement was also evaluated.ResultsBoth 90Y-DOTATOC and 177Lu-DOTATATE PRRT were well tolerated by patients without significant renal or bone marrow toxicity. The median follow-up was 73 months (range 5-146 months). The overall disease control rate (DCR) was 80% [95% confidence interval (CI) 68.9% to 91.9%] with a mean five cycles of therapy. However, 177Lu-DOTATATE patients showed a longer median overall survival (mOS) than those receiving 90Y-Dotatoc and a better DCR when higher dosages were administered, even if a direct comparison was not carried out. Syndromic patients had a poorer mOS. SDHx mutations did not interfere with treatment efficacy.ConclusionsPRRT is safe and effective for the treatment of patients with progressive mPPGL, especially at higher dosages. The longer mOS of 177Lu-DOTATATE-treated patients in our protocols indicates the former radiopharmaceutical as the better candidate for further clinical application.