Clinical risk factors for malignancy and overall survival in patients with pheochromocytomas and sympathetic paragangliomas: primary tumor size and primary tumor location as prognostic indicators

Current and future treatments for malignant pheochromocytoma and sympathetic paraganglioma

Pheochromocytomas (PHs) and sympathetic paragangliomas (SPGs) are rare neuroendocrine tumors. Approximately 17 % of these tumors are malignant, but because no molecular or histologic markers for malignancy exist, patients are often diagnosed with malignant PHs or SPGs after unresectable disease has formed. Patients with progressive metastatic tumors and overwhelming symptoms are currently treated with systemic chemotherapy and radiopharmaceutical agents such as metaiodobenzylguanidine. These therapies lead to partial radiographic response, disease stabilization, and symptomatic improvement in approximately 40 % of patients, and systemic chemotherapy is associated with a modest improvement in overall survival duration. However, over the past decade, substantial progress has been made in clinical, biochemical, and radiographic diagnosis of PHs and SPGs. Approximately 50 % of patients with malignant PHs and SPGs have been found to carry hereditary germline mutations in the succinate dehydrogenase subunit B gene (SDHB), and anti-angiogenic agents such as sunitinib have been found to potentially play a role in the treatment of malignant disease, especially in patients with SDHB mutations. In some patients, treatment with sunitinib has been associated with partial radiographic response, disease stabilization, decreased fluorodeoxyglucose uptake on positron emission tomography, and improved blood pressure control. These findings have led to the development of prospective clinical trials of new targeted therapies for metastatic disease. Here, we provide an updated review of the clinical and genetic predictors of malignant disease, radiographic diagnosis of malignant disease, and information from the most relevant studies of systemic therapies, as well as proposed treatment guidelines for patients with metastatic or potentially malignant PHs and SPGs.

Effect of HSP90 inhibitor in pheochromocytoma PC12 cells: an experimental investigation

This study aims to investigate whether the expression of heat shock protein 90 (HSP90) is associated with the malignant pheochromocytoma (PHEO) and the effects of 17-allylamino-17-demethoxygeldanamcyin (17-AAG) on the expression of vascular endothelial growth factor (VEGF) in PHEO cell line PC12. The expression of HSP90 was investigated in 38 paraffin-embedded samples of PHEO patients using immunohistochemistry. The time and concentration effects of 17-AAG were investigated in PHEO PC12 cells. Cell proliferation was measured by MTT assay and cell counting. Apoptosis was detected by flow cytometry. Positive staining for HSP90 was found in 14 of 17 malignant (82.35%) and in 5 of 21 (23.81%) benign PHEOs. There existed a significant statistical difference between the malignant group and the benign ones (P < 0.001). 17-AAG inhibited the proliferation of HCC cells in a time- and concentration-dependent manner. The apoptosis rates of PC12 cells after treatment with 0.1 μmol/L for 6, 12, 24, and 48 h were significantly higher than that in blank control group. 17-AAG significantly downregulated VEGF-165 protein level in PC12 cells. This study has confirmed that the specific HSP90 inhibitor 17-AAG can play a therapeutic role in malignant PHEO treatment, and HSP90 qualifies as a promising new target in malignant PHEO.

Pheochromocytoma/Paraganglioma: Review of perioperative management of blood pressure and update on genetic mutations associated with pheochromocytoma

Pheochromocytomas and paragangliomas are rare tumors with high morbidity rates caused by excessive catecholamine secretion, even though the majority of tumors are benign. The use of perioperative blockade regimens, together with improved surgical techniques, has greatly impacted the perioperative morbidity associated with these tumors. The old dogma of the "tumor of tens" no longer holds true. For example, at least one third of all pheochromocytomas and paragangliomas are hereditary, with mutations in 1 of 10 well-characterized susceptibility genes, and one quarter of all tumors are malignant. This review focuses on the perioperative management of pheochromocytoma and paragangliomas and the clinical implications of the associated genetic mutations.

Phaeochromocytoma masquerading as anxiety and depression

Patient: Female, 36

Final Diagnosis: Pheochromocytoma

Symptoms: Anxiety • depression

Medication: —

Clinical Procedure: —

Specialty: Oncology • endocrinology

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.

Bone metastases and skeletal-related events in patients with malignant pheochromocytoma and sympathetic paraganglioma

CONTEXT

Bone metastases (BM) can cause severe pain, spinal cord compression, pathological fractures, and/or hypercalcemia. These skeletal-related events (SREs) may cause immobilization, loss of independence, poor quality of life, and reduced survival. There is limited information on the clinical effects of BM and SREs in patients with malignant pheochromocytoma or sympathetic paraganglioma (PHEO/sPGL).

OBJECTIVES

We studied the prevalence and clinical characteristics of BM and SREs in patients with PHEO/sPGL and investigated the risk factors for SRE development.

DESIGN

Using a large institutional database, we conducted a retrospective study of 128 patients with malignant PHEO/sPGL at The University of Texas MD Anderson Cancer Center from 1967 through 2011.

RESULTS

Of the patients, 91 (71%) had BM, and 57 of these (63%) developed metachronous BM at a median time of 3.4 years (range, 5 months to 23 years) after the primary tumor diagnosis. Metastatic disease was confined exclusively to the skeleton in 26 of 128 (20%) patients. Sufficient information to assess SRE occurrence was available for 67 patients, and 48 of 67 (72%) patients had at least 1 SRE. The median overall survival for the 128 patients was 12 years for patients with only BM, 7.5 years for patients with nonosseous metastases, and 5 years for patients with both BM and nonosseous metastases (log rank test P value = .005). We were unable to identify factors predictive of SRE development, but the occurrence of a first SRE was associated with the development of subsequent SREs in 48% of subjects. In responsive patients, the use of systemic therapy was associated with fewer SREs (P < .0001).

CONCLUSIONS

BM and SREs are frequent in patients with malignant PHEO/sPGL. SREs often develop shortly after the diagnosis of BM; severe pain is the most frequent SRE. These patients should be followed long-term by a multidisciplinary team to promptly identify the need for medical or surgical intervention.

68Ga-DOTANOC PET/CT for baseline evaluation of patients with head and neck paraganglioma

The purpose of this study was to evaluate the role of (68)Ga-labeled DOTANOC PET/CT for baseline evaluation of patients with head and neck paragangliomas (HNPs).

METHODS

The data for 26 patients (mean age ± SD, 34.3 ± 10.4 y; 50% men) with known or suspected HNPs who underwent (68)Ga-DOTANOC PET/CT for staging were retrospectively analyzed. PET/CT was performed after intravenous injection of 132-222 MBq of (68)Ga-DOTANOC. The images were evaluated by 2 experienced nuclear medicine physicians in consensus, both qualitatively and quantitatively. The PET/CT findings were grouped as HNPs, paraganglioma at other sites (non-HNPs), and metastatic disease. The size and maximum standardized uptake values (SUVmax) were measured for all lesions. All of the patients also underwent whole-body (131)I-metaiodobenzylgunanidine ((131)I-MIBG) scintigraphy and conventional imaging (CT/MR imaging) of the head and neck region. Their results were compared with those of (68)Ga-DOTANOC PET/CT.

RESULTS

(68)Ga-DOTANOC PET/CT findings were positive in all 26 patients, and 78 lesions were detected. PET/CT imaging demonstrated 45 HNPS, 10 non-HNPs, and 23 metastatic sites. Fifteen patients (57.6%) had more than one site of disease on PET/CT. Among 45 HNPs, 26 were carotid body tumors (CBTs), 15 glomus jugulare, 3 glomus tympanicum, and 1 laryngeal paraganglioma. A positive correlation was seen between size and SUVmax of HNPs (ρ = 0.323; P = 0.030). The SUVmax of the CBTs was higher than that of jugulotympanic paragangliomas (P = 0.026). No correlation was seen between size and SUVmax (ρ = 0.069; P = 0.854) of non-HNPs. The size and SUVmax of non-HNPs were significantly less than those of HNPs (P = 0.029 and 0.047, respectively). (131)I-MIBG scintigraphy showed only 30 of the 78 lesions and was inferior to PET/CT (P < 0.0001). Conventional imaging (CT/MR imaging) was positive for 42 of 49 head and neck lesions and was inferior to PET/CT on direct comparison (P = 0.015). A combination of CT/MR imaging and (131)I-MIBG scintigraphy detected only 53 of 78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001).

CONCLUSION

(68)Ga-DOTANOC PET/CT is useful for the baseline evaluation of patients with HNPs and can demonstrate synchronous paragangliomas at other sites and distant metastases. It is superior to (131)I-MIBG scintigraphy and conventional imaging (CT/MR imaging) for this purpose.

Inherited mutations in pheochromocytoma and paraganglioma: why all patients should be offered genetic testing

BACKGROUND

Pheochromocytomas (PCC) and paragangliomas (PGL) are neuroendocrine tumors that, although rare, are an important cause of secondary hypertension because of the high morbidity and mortality. PCC/PGL are still thought of as the "tumor of tens," with 10 % being hereditary; however, recent population based studies suggest that up to 32 % of patients have a germline mutation in one of the known common susceptibility genes (including NF1, VHL, RET, SDHB, SDHD, and SDHC). Despite this, most patients in the United States are not referred for clinical genetic testing by their physicians. We aimed to examine the mutation prevalence in a clinic-based population in the United States.

METHODS

We performed a retrospective chart review of 139 consecutive patients with PCC/PGL from the medical genetics clinic at the hospital of the University of Pennsylvania from January 2004 through February 2012.

RESULTS

We found a 41 % overall mutation detection rate. Twenty-six percent of the cohort had a mutation in the SDHB or SDHD genes. Of patients with at least one PGL tumor outside the adrenal gland, 53 % had an identified mutation.

CONCLUSIONS

Forty-one percent of the cohort had a heritable mutation. The most commonly mutated gene was SDHB, which carries the highest risk of malignancy. These data, together with American Society of Clinical Oncology guidelines suggesting that genetic testing be performed if the risk of a hereditable mutation is at least 10 % or if it will affect medical management, strongly suggest that all patients with PCC/PGL should undergo clinical genetic testing.

High incidence of extraadrenal paraganglioma in families with SDHx syndromes detected by functional imaging with [18F]fluorodihydroxyphenylalanine PET

PURPOSE

Knowledge of the genetic backgrounds of hereditary syndromes, which are increasingly being characterized, enables genetic screening of family members of affected patients. Upon detection of a mutation, genetic counselling and clinical screening including imaging modalities and biochemical analyses are commonly performed.

METHODS

Unaffected, mutation-positive relatives of index patients with hereditary paraganglioma syndromes were offered PET imaging with [(18)F]fluorodihydroxyphenylalanine and the incidence of pathological findings was retrospectively analysed in relation to mutations of the succinate dehydrogenase enzyme complex. PET only or PET/CT was performed in 21 individuals from eight families with SDHD, one family with SDHC and two families with SDHB mutations. Screening was offered every 2 to 5 years.

RESULTS

Of the 21 individuals, 14 showed paraganglioma during screening. In particular, in only 2 of 15 patients with a SDHD mutation were the findings completely unremarkable on PET screening. However, false-negative lesions for abdominal manifestations in two SDHD-positive patients were detected.

CONCLUSION

FDOPA PET is a sensitive imaging modality which should be offered to patients with a detected SDHx (SDHD) mutation, preferably using a hybrid technique.

Malignant pheochromocytoma and paraganglioma: a population level analysis of long-term survival over two decades

BACKGROUND AND OBJECTIVES

Pheochromocytoma (PHEO) and paraganglioma (PGL) are rare tumors. Aims of this study were to describe and to compare demographic, clinical, pathologic, and survival characteristics of malignant PHEO and PGL.

METHODS

Patients were identified in SEER, 1988-2009. Analyses included chi-square, ANOVA, Kaplan-Meier, and Cox proportional hazard regression.

RESULTS

Gender distribution and mean age were similar for PHEO and PGL. Surgery was performed in 74.3% of PHEO and 78.9% of PGL; external beam radiation was administered in 8.0% of PHEO and 28.1% of PGL (P < 0.001). Compared to PGL, PHEO were larger (mean size 7.7 vs. 4.5 cm PGL, P = 0.001) and more were SEER-staged as localized (17.3% vs. 49.6%, respectively, P < 0.001). PGLs were more often located in the trunk than in the head/neck (53.8% vs. 38.0%, P < 0.001). PHEO had lower overall and disease-specific survival than PGL (54.0% and 73.5% vs. 73.3% and 80.5% for PGL, respectively, P < 0.001 and P = 0.118). Independent factors associated with mortality for PHEO included not undergoing surgery and metastases at diagnosis; for PGL, these were age 61-75 years, size ≥5 cm, and presenting with metastases.

CONCLUSIONS

Malignant PHEO has a more aggressive course than malignant PGL; long-term survival has not improved over the last two decades. Multi-institutional efforts should be pursued to seek novel treatments.

Treatment with sunitinib for patients with progressive metastatic pheochromocytomas and sympathetic paragangliomas

CONTEXT

Patients with progressive metastatic pheochromocytomas (PHEOs) or sympathetic paragangliomas (SPGLs) face a dismal prognosis. Current systemic therapies are limited.

OBJECTIVES

The primary end point was progression-free survival determined by RECIST 1.1 criteria or positron emission tomography with [(18)F]fluorodeoxyglucose/computed tomography ([(18)F]FDG-PET/CT), in the absence of measurable soft tissue targets. Secondary endpoints were tumor response according to RECIST criteria version 1.1 or FDG uptake, blood pressure control, and safety.

DESIGN

We conducted a retrospective review of medical records of patients with metastatic PHEO/SPGL treated with sunitinib from December 2007 through December 2011. An intention-to-treat analysis was performed.

PATIENTS AND SETTING

Seventeen patients with progressive metastatic PHEO/SPGLs treated at the Institut Gustave-Roussy and MD Anderson Cancer Center.

INTERVENTIONS

Patients treated with sunitinib.

RESULTS

According to RECIST 1.1, eight patients experienced clinical benefit; three experienced partial response, and five had stable disease, including four with predominant skeletal metastases that showed a 30% or greater reduction in glucose uptake on [(18)F]FDG-PET/CT. Of 14 patients who had hypertension, six became normotensive and two discontinued antihypertensives. One patient treated with sunitinib and rapamycin experienced a durable benefit beyond 36 months. The median overall survival from the time sunitinib was initiated was 26.7 months with a progression-free survival of 4.1 months (95% confidence interval = 1.4-11.0). Most patients who experienced a clinical benefit were carriers of SDHB mutations.

CONCLUSION

Sunitinib is associated with tumor size reduction, decreased [(18)F]FDG-PET/CT uptake, disease stabilization, and hypertension improvement in some patients with progressive metastatic PHEO/PGL. Prospective multi-institutional clinical trials are needed to determine the true benefits of sunitinib.

Gene expression profiles of phaeochromocytomas with ERBB2 overexpression reveal a new molecular mechanism tumourigenicity

OBJECTIVE

Phaeochromocytomas (PHEO) and functional paragangliomas (PGLs) are catecholamine-secreting neuroendocrine tumours. Although most PHEO/PGLs are benign, 10-35% present as (or develop into) malignant tumours with a poor prognosis. Overexpression of ERBB2 (v-erb-b2 erythroblastic leukaemia viral oncogene homologue 2) has been reported to be associated with malignant PHEO. We used gene expression profiling of PHEO/PGLs to gain a better understanding of the tumourigenic pathways associated with ERBB2.

METHODS

We used the Affymetrix Gene Chip U133 Plus 2·0 genome-wide gene expression cDNA microarray of 18 PHEO/PGLs (12 benign and six malignant, divided into two groups depending on ERBB2 expression levels) to analyse the gene expression patterns.

RESULTS

Unsupervised hierarchical cluster analysis of transcription profiles of 18 samples identified two dominant expression clusters corresponding to samples belonging to the ERBB2+ and ERBB2- groups. According to the gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) databases, the differentially expressed genes were classified into diverse functional categories and signalling pathways. In particular, the focal adhesion signalling pathway showed significant differences between the groups; specifically, the FAK-Src-MAPK pathway was prominently activated in the ERBB2+ group.

CONCLUSIONS

In summary, ERBB2+ PHEO/PGLs have a distinct expression pattern compared with the ERBB2- group. The focal adhesion signalling pathway may participate in ERBB2-induced tumourigenesis in PHEO/PGLs.

Plasma methoxytyramine: a novel biomarker of metastatic pheochromocytoma and paraganglioma in relation to established risk factors of tumour size, location and SDHB mutation status

BACKGROUND

There are currently no reliable biomarkers for malignant pheochromocytomas and paragangliomas (PPGLs). This study examined whether measurements of catecholamines and their metabolites might offer utility for this purpose.

METHODS

Subjects included 365 patients with PPGLs, including 105 with metastases, and a reference population of 846 without the tumour. Eighteen catecholamine-related analytes were examined in relation to tumour location, size and mutations of succinate dehydrogenase subunit B (SDHB).

RESULTS

Receiver-operating characteristic curves indicated that plasma methoxytyramine, the O-methylated metabolite of dopamine, provided the most accurate biomarker for discriminating patients with and without metastases. Plasma methoxytyramine was 4.7-fold higher in patients with than without metastases, a difference independent of tumour burden and the associated 1.6- to 1.8-fold higher concentrations of norepinephrine and normetanephrine. Increased plasma methoxytyramine was associated with SDHB mutations and extra-adrenal disease, but was also present in patients with metastases without SDHB mutations or those with metastases secondary to adrenal tumours. High risk of malignancy associated with SDHB mutations reflected large size and extra-adrenal locations of tumours, both independent predictors of metastatic disease. A plasma methoxytyramine above 0.2nmol/L or a tumour diameter above 5cm indicated increased likelihood of metastatic spread, particularly when associated with an extra-adrenal location.

CONCLUSION

Plasma methoxytyramine is a novel biomarker for metastatic PPGLs that together with SDHB mutation status, tumour size and location provide useful information to assess the likelihood of malignancy and manage affected patients.

Pheochromocytoma and paraganglioma: imaging characteristics

The accurate diagnosis of adult pheochromocytoma and paraganglioma necessitates a multidisciplinary approach that includes clinical history, biochemical testing, and multimodality imaging such as computed tomography, magnetic resonance imaging, and nuclear medicine studies. This review illustrates the different imaging characteristics of primary adult pheochromocytomas as well as both sympathetic and parasympathetic paragangliomas. The review also describes known genetic associations and shows common metastatic patterns. Knowledge of the diverse appearance of pheochromocytomas and paragangliomas can result in early initial diagnosis or detection of disease recurrence thereby affecting patient management and prognosis.

Pheochromocytoma and paraganglioma: understanding the complexities of the genetic background

Pheochromocytomas and paragangliomas (PCC/PGL) are tumors derived from the adrenal medulla or extra-adrenal ganglia, respectively. They are rare and often benign tumors that are associated with high morbidity and mortality due to mass effect and high circulating catecholamines. Although most PCCs and PGLs are thought to be sporadic, over one third are associated with 10 known susceptibility genes. Mutations in three genes causing well characterized tumor syndromes are associated with an increased risk of developing PCCs and PGLs, including VHL (von Hippel-Lindau disease), NF1 (Neurofibromatosis Type 1), and RET (Multiple Endocrine Neoplasia Type 2). Mutations in any of the succinate dehydrogenase (SDH) complex subunit genes (SDHA, SDHB, SDHC, SDHD) can lead to PCCs and PGLs with variable penetrance, as can mutations in the subunit cofactor, SDHAF2. Recently, two additional genes have been identified, TMEM127 and MAX. Although these tumors are rare in the general population, occurring in two to eight per million people, they are more commonly associated with an inherited mutation than any other cancer type. This review summarizes the known germline and somatic mutations leading to the development of PCC and PGL, as well as biochemical profiling for PCCs/PGLs and screening of mutation carriers.

Diagnostic tests and biomarkers for pheochromocytoma and extra-adrenal paraganglioma: from routine laboratory methods to disease stratification

The laboratory workup of patients with pheochromocytoma and extra-adrenal paraganglioma (PPGLs) has traditionally focused on biochemical measurements of tumor secretory products or their metabolites, with ultimate diagnosis resting on routine histopathology and immunohistochemistry. While such testing remains important, the needs to distinguish potentially metastatic from benign tumors and to identify tumors with a hereditary basis have stimulated searches for additional means to stratify patients according to risk of metastasis or presence of a particular mutation. Biomarkers based on traditional biochemical tests, such as profiles of catecholamine metabolites and granin-derived peptides, provide utility for both purposes, while novel biomarkers are being identified by proteomic and transcriptomic studies, the latter including microRNA expression profiling. Histopathological scoring methods for predicting metastatic potential, such as the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS), are limited by poor interobserver concordance, discrepant results between studies and incomplete knowledge of how scores relate to genotype. Immunohistochemical staining for succinate dehydrogenase (SDH) subunit B to triage patients for genetic testing of SDH subunit genes illustrates the growing importance of pathology as an adjunct to genetic testing for disease stratification. Although considerable effort has been expended on microarray-based platforms to identify biomarkers of malignancy, as yet, none of those proposed have been demonstrated to reliably discriminate malignant from benign disease any better than the PASS. Because of the heterogeneity of PPGLs and variable time between first appearance of tumors and identification of metastases, any prospective study to establish prognostic efficacy requires large numbers of patients and extended follow-up.

Pheochromocytomas and paragangliomas: assessment of malignant potential

Pheochromocytomas and paragangliomas (PPGLs) are rare catecholamine-secreting tumors which arise from the adrenal glands or sympathetic neuronal tissue. Malignant transformation of these tumors occurs in a significant proportion and may therefore lower overall survival rates. In patients with PPGLs it is impossible to identify malignant disease without the presence of metastatic disease, something which can occur as long as 20 years after initial surgery. Early identification of malignant disease would necessitate a more aggressive treatment approach, something which may result in better disease outcome. We have therefore reviewed possible predictors of malignancy and current developments in order to help clinicians to swiftly assess malignant potential in patients with PPGLs. Currently, there is no absolute marker which can objectively reflect malignant potential. Tumor size is the most reliable predictor and should therefore be used as the baseline characteristic. The combination of various clinical markers (extra-adrenal disease and post-operative hypertension), biochemical markers (high dopamine, high norepinephrine and epinephrine to total catecholamine ratio) and/or histological markers (SNAIL, microRNAs and/or microarray results) can raise or lower the suspicion of malignancy. Furthermore, we discuss how clinical markers may affect biochemical results linked to malignancy, how biochemical results may distinguish hereditary syndromes, the role of imaging in determining malignant potential and tumor detection, and recent results of proposed histological markers.

Clinical benefits of systemic chemotherapy for patients with metastatic pheochromocytomas or sympathetic extra-adrenal paragangliomas: insights from the largest single-institutional experience

BACKGROUND

The objective of this study was to evaluate the clinical benefits of systemic chemotherapy for patients with metastatic pheochromocytomas or sympathetic paragangliomas by assessing reductions in tumor size and blood pressure and improvements in overall survival (OS).

METHODS

The authors retrospectively reviewed the medical records of patients with metastatic pheochromocytomas-sympathetic paragangliomas who had received chemotherapy at The University of Texas MD Anderson Cancer Center.

RESULTS

Clinical benefit and OS were assessed. Of 54 patients who received chemotherapy, 52 patients were evaluable for response. Seventeen patients (33%) experienced a response, which was defined as decreased or normalized blood pressure/decreased number and dosage of antihypertensive medications and/or reduced tumor size after the first chemotherapy regimen. The median OS was 6.4 years (95% confidence interval [CI], 5.2-16.4 years) for responders and 3.7 years (95% CI, 3.0-7.5 years) for nonresponders. Among the patients who had synchronous metastatic disease, a positive response at 1 year after the start of chemotherapy was associated with a trend toward longer OS (log-rank test; P = .095). In a multivariate Cox proportional hazards model, the effect of response to chemotherapy on OS was significant (hazard ratio, 0.22; 95% CI, interval: 0.05-1.0; P = .05). All responders had received dacarbazine and cyclophosphamide. Vincristine was included for 14 responders, and doxorubicin was included for 12 responders. The clinical factors that predicted response to chemotherapy could not be identified.

CONCLUSIONS

The current results indicted that chemotherapy may decrease tumor size and facilitate blood pressure control in approximately 33% of patients with metastatic pheochromocytoma-sympathetic paraganglioma. These patients exhibited longer survival.

Posterior retroperitoneoscopic adrenalectomy is a safe and effective alternative to transabdominal laparoscopic adrenalectomy for pheochromocytoma

INTRODUCTION

Laparoscopic adrenalectomy (LA) is a safe minimally invasive approach for treatment of pheochromocytoma (PHEO). Posterior retroperitoneoscopic adrenalectomy (PRA) is an alternative minimally invasive technique; however, there is a lack of data regarding the appropriateness of this approach in patients with PHEO.

METHODS

Our endocrine surgery database was queried to identify patients who underwent LA or PRA for PHEO. Patient and tumor characteristics, as well as operative details and postoperative course were compared between the 2 groups.

RESULTS

LA or PRA was attempted in 46 patients with PHEO (23 LA, 23 PRA). There were no differences in age, BMI, or tumor size between these groups. PRA was associated with significantly reduced operative times (99 min vs 145 min, P < .001), estimated blood loss (8.4 cc vs 123.8 cc, P = .02), and postoperative length of stay (1.9 nights vs 3.1 nights, P < .01). There was no significant difference in rates of conversion to an open procedure or perioperative complications between these groups.

CONCLUSION

LA and PRA are both safe and effective approaches in patients with PHEO. In our experience, PRA results in decreased operative times, blood loss, and postoperative length of stay compared with LA. PRA has become our preferred approach for patients with PHEO.

Management of medullary thyroid carcinoma and MEN2 syndromes in childhood

Medullary thyroid carcinoma (MTC) and the multiple endocrine neoplasia (MEN) type 2 syndromes are rare but important endocrine diseases that are increasingly managed by pediatric providers. MTC is generally associated with a favorable prognosis when diagnosed during childhood, where it frequently occurs secondary to activating mutations in the RET proto-oncogene and arises from pre-existing C-cell hyperplasia. MEN2A accounts for 90-95% of childhood MTC cases and is most commonly due to mutations in codon 634 of RET. MEN2B is associated with the most aggressive clinical presentation of MTC and is almost always due to the Met918Thr mutation of RET. Surgery is the primary treatment and only chance of cure, although the advent of targeted therapies seems to be improving progression-free survival in advanced cases. Since the discovery of the role of RET in MEN2A, considerable advances in the management of this syndrome have occurred, and most of the children with MEN2A who have undergone early thyroidectomy will now lead full, productive lives. Strong genotype-phenotype correlations have facilitated the development of guidelines for interventions. Contemporary approaches for deciding the appropriate age at which surgery should take place incorporate data from ultrasonography and calcitonin measurements in addition to the results of genotyping. To optimize care and to facilitate ongoing research, children with MTC and the MEN2 syndromes are optimally treated at tertiary centers with multidisciplinary expertise.

Novel germline SDHD mutation: diagnosis and implications to the patient

A 54-year-old man presented with hypertensive crisis. He was found to have bilateral pheochromocytomas and left paraaortic sympathetic paraganglioma. Although he had no family history of paragangliomas or pheochromocytomas, he had been diagnosed with bilateral head and neck paragangliomas 10 years prior. The patient had symptoms of catecholamine excess exacerbated by vanilla ice-cream consumption. Biochemical testing revealed elevated plasma-free metanephrines and chromogranin A levels. Computed tomography showed bilateral carotid body tumors and four reteroperitoneal masses (two in the right adrenal, one in the left adrenal and one in the left paraaortic area). Metaiodobenzylguanidine-SPECT scans showed functional tumors in both the adrenal gland and left paraaortic area. Fluorine 18-fluorodeoxyglucose positron emission tomography did not show any visceral or skeletal metastasis. We carried out gene mutation analysis for succinate dehydrogenase complex subunit B, and succinate dehydrogenase complex subunit D. The patient was diagnosed with hereditary paraganglioma syndrome type 1 with a previously unreported subunit D mutation in exon 3 (c.198G > A, p.W66X). He was treated with phenoxybenzamine at 10 mg/day and with metoprolol at 12.5 mg/day. His blood pressures as well as symptoms of catecholamine excess were controlled. He then underwent bilateral adrenalectomy and reteroperitoneal dissection. His blood pressure normalized and he discontinued antihypertensive medications after surgery. He is currently on replacement therapy with hydrocortisone and fludrocortisone.