Courses of Malignant Pheochromocytoma: Implications for Therapy

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.

Brain Metastasis of Pheochromocytoma: Diagnostic and Therapeutic Challenge

BACKGROUND

Pheochromocytoma brain metastasis is extremely rare. Few cases have been reported in the literature. Therefore, diagnosis and effective treatment of these lesions are difficult.

CASE DESCRIPTION

Here, we report the case of 29-year-old woman, who was operated on for a right adrenal pheochromocytoma. Fourteen months later, a posterior fossa tumor was diagnosed. Radiologic findings mimicked an extra-axial lesion. The radiologic differential diagnosis was difficult even using magnetic resonance imaging spectroscopy. The patient was operated on through a retrosigmoid approach. Local recurrence occurred 6 months after first surgery. The patient died 1 month later, despite a second operation.

CONCLUSIONS

Although the occurrence of brain metastases in pheochromocytoma is not prevalent, patients presenting with suggestive features need to be carefully considered. Magnetic resonance imaging can help in differential diagnosis with a primary brain tumor. There are no established guidelines for the treatment of pheochromocytoma brain metastasis, for which the prognosis remains dismal, despite effective surgery.

Spine Stereotactic Radiosurgery for Metastatic Pheochromocytoma

Purpose: Despite aggressive primary treatment, up to 13.5% of patients diagnosed with pheochromocytoma may develop metastases, most often affecting the axial skeleton. Given that systemic therapy options are often inadequate, local therapy remains the cornerstone of palliation for these patients. Historically poor responses to standard fractionated radiotherapy have led to the consideration of stereotactic radiosurgery as an option to overcome potential radioresistance and provide durable local control of these tumors. Here we report our institutional experience in treating spine metastases from pheochromocytoma with spine stereotactic radiosurgery (SSRS).

Methods and materials: Our clinical databases were retrospectively reviewed for patients with metastatic pheochromocytoma treated with SSRS from 2000-2017. Seven patients with 16 treated metastatic spinal lesions were identified. Local control was evaluated using magnetic resonance imaging (MRI). Pain and symptom data were assessed to evaluate toxicity using Common Terminology Criteria for Adverse Events (CTCAE) v4.03. The Kaplan-Meier method was used to assess local control and overall survival (OS).

Results: Median follow-up for treated lesions was 11 months (range 2.2 - 70.8). Most lesions were treated to a dose of 27 Gy in three fractions (62.5%). Other fractionation schemes included 24 Gy in one fraction (25%), 16 Gy in one fraction (6.3%), and 18 Gy in three fractions (6.3%). Treatment sites included the cervical spine (18.8%), thoracic spine (37.5%), lumbar spine (31.3%), and sacrum (12.5%). The crude local control rate was 93.7%, with one thoracic spine lesion progressing 20.7 months after treatment with 24 Gy in one fraction. Kaplan-Meier OS rates at 1 and 2 years after SSRS were 71.4% and 42.9%, respectively. Most common toxicities included acute grade 1-2 pain and fatigue. There was one case of vertebral fracture in a cervical spine lesion treated to 27 Gy in three fractions, which was managed non-surgically.

Conclusion: Very few studies have explored the use of SSRS in metastatic pheochromocytoma. Our data suggest this modern radiation modality is effective, safe, and provides durable local control to palliate symptoms and potentially limit further metastatic seeding. Larger patient numbers and longer follow-up will further define the role of SSRS as a treatment option in these patients.

A phase I clinical trial for [131I]meta-iodobenzylguanidine therapy in patients with refractory pheochromocytoma and paraganglioma

Refractory pheochromocytoma and paraganglioma (PPGL) have a poor prognosis and the treatment strategy remains to be established. This multi-institutional phase I study was performed to determine the safety, dose-limiting toxicity (DLT), and efficacy of [¹³¹I]-meta-iodobenzylguanidine (¹³¹I-mIBG) therapy for refractory PPGLs. Twenty patients with refractory PPGL were enrolled in this study. We administered fixed doses of ¹³¹I-mIBG to all patients, delivering a second and third course of ¹³¹I-mIBG to eight and three patients, respectively. During the 20 weeks after ¹³¹I-mIBG injection, the authors surveyed the adverse events in accordance with the Common Terminology Criteria for Adverse Events. All patients experienced adverse events and adverse reactions, but none experienced a grade 4 adverse event. Twelve weeks after ¹³¹I-mIBG injection, examinations for the evaluation of therapeutic effects was performed in accordance with the Response Evaluation Criteria in Solid Tumours (RECIST). The best overall response rates (based on RECIST categories) were 10% (complete response), 65% (stable disease), 15% (progressive disease), and 10% (not all evaluated). The efficacy and safety of ¹³¹I-mIBG therapy was shown in patients with refractory PPGL, and DLT was observed in neither single nor repeated ¹³¹I-mIBG therapy, indicating a tolerability for ¹³¹I-mIBG therapy.

LOCALLY INVASIVE PHEOCHROMOCYTOMA COMBINED WITH PRIMARY MALIGNANT ADRENAL LYMPHOMA

Objective

Pheochromocytoma (PHEO) combined with primary adrenal lymphoma is extremely rare. We describe a case of locally invasive PHEO combined with primary malignant lymphoma.

Methods

We provide a case description with biochemical analyses, imaging, and pathologic findings.

Results

A 79-year-old male presented with a 17-cm, complex mass in the left adrenal gland with non-contrast Hounsfield units of 100 and left para-aortic enlarged lymph nodes imaged by computed tomography. Biochemical evaluation showed plasma and 24-hour urinary normetanephrine significantly elevated about 22 times (about 13.5 times above the normal upper limit) while metanephrine levels were normal. With adequate perioperative preparation, en bloc resection of the left adrenal gland was performed. The pathology revealed a tumor consisting of B-cell lymphoma, a PHEO forming a large adrenal mass with soft tissue invasion with extensive sclerosis and a separate nodule with PHEO without sclerosis. Immunohistochemistry and in situ hybridization of the lymphoma were consistent with Epstein-Barr virus-positive, diffuse large B-cell lymphoma. Immunohistochemistry of the PHEO was positive for chromogranin, synaptophysin, and S100. The Ki67 index was 8.7% and PHEO of the adrenal gland scaled score was 8 (≥4 is considered potentially malignant).

Conclusion

To the best of our knowledge this is the first case demonstrating locally invasive and potentially malignant PHEO combined with primary malignant lymphoma in the same adrenal gland.

What determines mortality in malignant pheochromocytoma? – Report of a case with eighteen-year survival and review of the literature

Pheochromocytoma (PCC) is a tumor derived from adrenomedullary chromaffin cells. Prognosis of malignant PCC is generally poor due to local recurrence or metastasis. We aim to report a case of malignant PCC with 18-year survival and discuss which factors may be related to mortality and long-term survival in malignant pheochromocytoma. The patient, a 45-year-old man, reported sustained arterial hypertension with paroxysmal episodes of tachycardia, associated with head and neck burning sensation, and hand and foot tremors. Diagnosis of PCC was established biochemically and a tumor with infiltration of renal parenchyma was resected. No genetic mutation or copy number variations were identified in SDHB, SDHD, SDHC, MAX and VHL. Over 18 years, tumor progression was managed with 131I-MIBG (iodine-metaiodobenzylguanidine) and 177Lutetium-octreotate therapy. Currently, the patient is asymptomatic and presents sustained stable disease, despite the presence of lung, para-aortic lymph nodes and femoral metastases. Adequate response to treatment with control of tumor progression, absence of significant cardiovascular events and other neoplasms, and lack of mutations in the main predisposing genes reported so far may be factors possibly associated with the prolonged survival in this case. Early diagnosis and life-long follow-up in patients with malignant pheochromocytoma are known to be crucial in improving survival.

Surgical Treatment of Malignant Pheochromocytoma and Paraganglioma: Retrospective Case Series

INTRODUCTION

Pheochromocytoma and paraganglioma (PPGL) are rare neoplasms; about 10% are malignant. Literature regarding possible benefit from resection is extremely limited.

METHODS

A 20 year review of all patients undergoing surgery for malignant PPGL at the Mayo Clinic Rochester Campus between 1994 and June 2014 was performed.

RESULTS

We identified 34 patients undergoing surgery for malignant PPGL. Median follow up was 6 and 5 years survival was 90% (median 11 years). Complete resection (R0) was achieved in 14 patients (41%). Median disease-free survival was 4.6 years for patients with R0 resection (up to 12 years). Only eight patients (23%) were disease-free on last follow up. Elevated preoperative fractionated metanephrines or catecholamines were documented in 23 patients (68%); these normalized in 13 of 23 patients (56%) postoperatively-with symptom relief in 15 of 18 preoperatively symptomatic patients (79%). Among 23 patients with hormone-producing tumors, significant reduction in number of antihypertensive medications was also noted postoperatively; 11 patients have remained off all antihypertensives, 6 required 1 medication, 1 required 2, while 5 required full blockade with phenoxybenzamine and a beta-adrenergic blocker.

CONCLUSION

Surgery plays a significant role in the management of selected malignant PPGL. Resection can be effective in normalizing or significantly reducing levels of catecholamines and metanephrines, and can improve hormone-related symptoms and hypertension. Surgical resection, either complete or incomplete, is associated with durable survival despite a high rate of tumor recurrence.

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.

Draft guidelines regarding appropriate use of (131)I-MIBG radiotherapy for neuroendocrine tumors : Guideline Drafting Committee for Radiotherapy with (131)I-MIBG, Committee for Nuclear Oncology and Immunology, The Japanese Society of Nuclear Medicine

Since the 1980s when clinical therapeutic trials were initiated, (131)I-MIBG radiotherapy has been used in foreign countries for unresectable neuroendocrine tumors including malignant pheochromocytomas and neuroblastomas. In Japan, (131)I-MIBG radiotherapy has not been approved by the Ministry of Health, Labour and Welfare; however, personally imported (131)I-MIBG is now available for therapeutic purposes in a limited number of institutions. These updated draft guidelines aim to provide useful information concerning (131)I-MIBG radiotherapy, to help prevent side effects and protect physicians, nurses, other health care professionals, patients and their families from radiation exposure. The committee has also provided appendices on topics such as practical guidance for attending physicians, patient management, and referring physicians.

Prognostic values of initial responses to low-dose (131)I-MIBG therapy in patients with malignant pheochromocytoma and paraganglioma

PURPOSE

We retrospectively examined whether or not initial responses of first low-dose (131)I-meta-iodo-benzyl-guanidine radiotherapy ((131)I-MIBG therapy) in patients with malignant pheochromocytoma and paraganglioma had prognostic values.

MATERIALS AND METHODS

This study included 26 patients with malignant pheochromocytoma (n = 18) and paraganglioma (n = 8) who underwent the first (131)I-MIBG therapy between October 2001 and September 2007. Based on the initial subjective, hormonal, scintigraphic, and objective responses to (131)I-MIBG therapy, the responses were divided into progression disease (PD) and non-PD. We examined the following factors for prognostic significance: sex, age, disease, initial diagnosis (benign or malignant pheochromocytoma), hypertension, diabetes mellitus, palpitations, symptoms related to bone metastases, and number of low-dose (131)I-MIBG therapy. Univariate Cox proportional regression analysis was used to identify prognostic factors for overall survival. Overall survival was analyzed by Kaplan-Meier method and the curves were compared using the log-rank test.

RESULTS

The median survival time was 56 months. In the follow-up period, 16 patients died from exacerbation of their diseases. Univariate analysis showed that the hormonal PD [hazard ratio (HR) 3.20, P = 0.034, confidence interval (CI) 1.09-9.93], objective PD (HR 11.89, P = 0.0068, CI 2.14-65.85), single-time (131)I-MIBG therapy (HR 3.22, P = 0.020, CI 1.21-8.79), hypertension (HR 2.93, P = 0.044, CI 1.02-10.50), and symptoms related to bone metastases (HR 3.54, P = 0.023, CI 1.18-13.04) were bad prognostic factors for overall survival. Kaplan-Meier analysis demonstrated that the hormonal non-PD (P = 0.026), objective non-PD (P = 0.0002), multiple-time (131)I-MIBG therapy (P = 0.013), and no symptom related to bone metastases (P = 0.024) were significantly associated with good prognosis. Overall survival rate was 70 and 50 % at 5 years from the initial diagnosis and from the first (131)I-MIBG therapy, respectively.

CONCLUSION

The hormonal and objective responses to the first low-dose (131)I-MIBG therapy as well as complication of hypertension and symptoms related to bone metastases may be prognostic factors in patients with malignant pheochromocytoma and paraganglioma.

Molecular and therapeutic advances in the diagnosis and management of malignant pheochromocytomas and paragangliomas

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare catecholamine-secreting tumors derived from chromaffin cells originating in the neural crest. These tumors represent a significant diagnostic and therapeutic challenge because the diagnosis of malignancy is frequently made in retrospect by the development of metastatic or recurrent disease. Complete surgical resection offers the only potential for cure; however, recurrence can occur even after apparently successful resection of the primary tumor. The prognosis for malignant disease is poor because traditional treatment modalities have been limited. The last decade has witnessed exciting discoveries in the study of PCCs and PGLs; advances in molecular genetics have uncovered hereditary and germline mutations of at least 10 genes that contribute to the development of these tumors, and increasing knowledge of genotype-phenotype interactions has facilitated more accurate determination of malignant potential. Elucidating the molecular mechanisms responsible for malignant transformation in these tumors has opened avenues of investigation into targeted therapeutics that show promising results. There have also been significant advances in functional and radiological imaging and in the surgical approach to adrenalectomy, which remains the mainstay of treatment for PCC. In this review, we discuss the currently available diagnostic and therapeutic options for patients with malignant PCCs and PGLs and detail the molecular rationale and clinical evidence for novel and emerging diagnostic and therapeutic strategies.

Theranostics: evolution of the radiopharmaceutical meta-iodobenzylguanidine in endocrine tumors

Since 1981, meta-iodobenzylguanidine (MIBG), labeled with (131)I and later (123)I, has become a valuable agent in the diagnosis and therapy of a number of endocrine tumors. Initially, the agent located pheochromocytomas and paragangliomas (PGLs), both sporadic and familial, in multiple anatomic sites; surgeons were thereby guided to excisional therapies, which were previously difficult and sometimes impossible. The specificity in diagnosis has remained above 95%, but sensitivity has varied with the nature of the tumor: close to 90% for intra-adrenal pheochromocytomas but 70% or less for PGLs. For patients with neuroblastoma, carcinoid tumors, and medullary thyroid carcinoma, imaging with radiolabeled MIBG portrays important diagnostic evidence, but for these neoplasms, use has been primarily as an adjunct to therapy. Although diagnosis by radiolabeled MIBG has been supplemented and sometimes surpassed by newer scintigraphic agents, searches by this radiopharmaceutical remain indispensable for optimal care of some patients. The radiation imparted by concentrations of (131)I-MIBG in malignant pheochromocytomas, PGLs, carcinoid tumors, and medullary thyroid carcinoma has reduced tumor volumes and lessened excretions of symptom-inflicting hormones, but its value as a therapeutic agent is being fulfilled primarily in attacks on neuroblastomas, which are scourges of children. Much promise has been found in tumor disappearance and prolonged survival of treated patients. The experiences with therapeutic (131)I-MIBG have led to development of new tactics and strategies and to well-founded hopes for elimination of cancers. Radiolabeled MIBG is an exemplar of theranostics and remains a worthy agent for both diagnosis and therapy of endocrine tumors.

Unique manifestations of catecholamine release in malignant pheochromocytoma: an experience within an inpatient palliative care unit

Malignant pheochromocytoma is a rare disorder. We describe the case of a 41-year-old female with disseminated metastatic pheochromocytoma who was admitted for ongoing palliative and supportive care within an inpatient palliative care unit. Predominant symptoms included severe gastrointestinal pseudo-obstruction and orthostatic hypotension Pseudo-obstruction management included percutaneous enterogastric and percutaneous enterojejunostomy tubes for gastric decompression and delivery of nutrition, respectively. Debilitating symptoms of orthostatic hypotension were mitigated with judicious fluid balance and appropriate use of adrenergic blocking agents. The potential for metoclopramide to worsen symptoms also was a significant component of management. The case presents rare features of this unusual disease and is unique for its setting within the confines of a palliative care unit.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

INTRODUCTION

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

METHODS

This review summarizes our current knowledge on how benign and malignant tumors can be distinguished.

CONCLUSION

Due to the rarity of malignant PCCs/PGLs and the obvious difficulties in distinguishing benign and malignant PCCs/PGLs, any patient with a PCC/PGL should be treated in a specialized center where a multidisciplinary setting with specialized teams consisting of radiologists, endocrinologist, oncologists, pathologists and surgeons is available. This would also facilitate future studies to address the existing diagnostic and/or therapeutic obstacles.

Malignant pheochromocytoma: a review

BACKGROUND

Pheochromocytomas are rare catecholamine-secreting tumors. Approximately 10 percent of pheochromocytomas are malignant. Traditionally, there has been no reliable method available to predict the malignant potential of pheochromocytoma. However, recent research has increased focus on differentiating at the time of surgery/diagnosis those pheochromocytoma tumors which have malignant potential. In this review, we discuss the current information known of malignant pheochromocytomas.

DATA SOURCES

The PubMed database was searched for articles on malignant pheochromocytoma published between 1993 and 2010.

CONCLUSIONS

The difficult task of predicting the malignant potential of a pheochromocytoma has yet to be answered definitively. However, all the studies presented give an idea of what we may look for in these tumors at the time of diagnosis. We have provided an algorithm based on the most current information known. A much larger study should be performed to test many of these theories with enough power to determine a standard of care.

Survival of patients with metastatic malignant pheochromocytoma and efficacy of combined cyclophosphamide, vincristine, and dacarbazine chemotherapy

CONTEXT

About 10% of pheochromocytomas are malignant. Exact survival has not been reported, nor has an analysis of the efficacy of chemotherapy on survival time.

OBJECTIVE

The aim of this study was to analyze the survival curves and survival times of patients with malignant pheochromocytoma and to determine the efficacy of chemotherapy on prolongation of life.

DESIGN

An inception cohort and Kaplan-Meier survival analysis was conducted.

PATIENTS AND OUTCOME MEASURES

Thirty-two patients with metastasized malignant pheochromocytoma were analyzed for survival. Twenty-five patients had undergone excision of their primary tumors. Survival curves were compared among the 16 patients in this group treated with combined chemotherapy using cyclophosphamide, vincristine and dacarbazine (CVD) and the nine patients not treated with chemotherapy.

RESULTS

The survival curve of the 32 patients declined continuously and linearly to at least 20 yr after the diagnosis of pheochromocytoma. The 50% survival rate was estimated to be 14.7 yr. In the 25 patients whose primary tumor was excised, patients who already had metastases at the time of pheochromocytoma diagnosis had better survival than those whose metastases were found later. The survival rate after diagnosis of metastasis was worse in the CVD group than in controls. When the effects of CVD were examined after stratifying several factors, female gender and adrenal origin of tumor were found to be negative prognostic factors for CVD chemotherapy.

CONCLUSION

The present study revealed a long survival time. CVD chemotherapy was not shown to extend survival, especially for women and patients with adrenal gland-derived primary tumors.

A clinical overview of pheochromocytomas/paragangliomas and carcinoid tumors

Pheochromocytomas/paragangliomas are rare tumors; most are sporadic. Biochemical proof of disease is better with measurement of plasma metanephrines and less cumbersome than determinations in urine; its implementation is expanding. Anatomical imaging with computed tomography or magnetic resonance imaging should be followed by functional (nuclear medicine) imaging: chromaffin tumor-specific methods are preferred. Treatment is surgical; for nonoperable disease other options are available. Overall 5-year survival is 50%. Carcinoid tumors derive from serotonin-producing enterochromaffin cells in the fore-, mid- or hindgut. Biochemical screening (and follow-up) is done with measurements of 5-hydroxyindoloacetic acid in urine. For most carcinoids, functional imaging is better than other modalities in localizing primary tumors. Surgery is the treatment of choice; nonresectable tumors are treated with somatostatin analogs or chemotherapy. Overall 5-year survival for patients with carcinoids is 67%.