[Show abstract][Hide abstract] ABSTRACT: The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2.
This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy.
1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0·57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent.
The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.
European Union, German Cancer Foundation, Arthur Blank Foundation, Italian Government, Charles University, Czech Ministry of Health, Nanjing Military Command, National Science Centre Poland, National Research Council for Scientific and Technological Development, and State of São Paulo Research Foundation.
The Lancet Oncology 04/2014; · 25.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Extract: The fascination of hereditary tumor diseases, especially von Hippel-Lindau disease (VHL) and pheochromocytoma, has dominated my academic life for three decades. My background was the warm and rich atmosphere which gave me my parents, Colonel Joachim Neumann and Mechtild Zuckschwerdt, PhD, MA, descendent of an industrial family from Magdeburg. Together with 3 sisters and a brother, I spent my youth in Brunswick, Hamburg and Bonn with a classical education including Latin and Greek. I served 2 years in the artillery of the German army. From 1969 until 1974, I studied medicine at the Universities of Bonn and Heidelberg ...
Endocrine Related Cancer 01/2014; · 5.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This case describes a 50-yr-old man who was admitted to the Urology Ward upon the suspicion of a left kidney tumor. As part of the pre-operative check-up, an ultrasound and computed tomography of the kidneys were conducted. The results confirmed the initial diagnosis. The postoperative diagnosis was extra-adrenal pararenal phaeochromocytoma (ePCC) with succinate dehydrogenase complex, subunit B (SDHB) gene mutation. During the follow-up, a second tumor was detected by 3,4-dihydroxy-6-F-18-fluoro-L-phenylalanine positron emission tomography/computed tomography F-DOPA-PET CT that resulted in another surgery with complete resection of the tumor. The patient and his family were counseled by a genetic laboratory and remain under surveillance.
Central European journal of urology. 01/2014; 67(2):162-6.
[Show abstract][Hide abstract] ABSTRACT: Pheochromocytomas (PCCs) develop from the adrenal medulla and are often part of a hereditary syndrome such as von Hippel-Lindau (VHL) syndrome. In VHL, only about 30 % of patients with a VHL missense mutation develop PCCs. Thus, additional genetic events leading to formation of such tumors in patients with VHL syndrome are sought. SDHAF2 (previously termed SDH5) and SDHD are both located on chromosome 11q and are required for the function of mitochondrial complex II. While SDHAF2 has been shown to be mutated in patients with paragangliomas (PGLs), SDHD mutations have been found both in patients with PCCs and in patients with PGLs.
Because loss of 11q is a common event in VHL-associated PCCs, we aimed to investigate whether SDHAF2 and SDHD are targets. In the present study, 41 VHL-associated PCCs were screened for mutations and loss of heterozygosity (LOH) in SDHAF2 or SDHD. Promoter methylation, as well as mRNA expression of SDHAF2 and SDHD, was studied. In addition, immunohistochemistry (IHC) of SDHB, known to be a universal marker for loss of any part the SDH complex, was conducted.
LOH was found in more than 50 % of the VHL-associated PCCs, and was correlated with a significant decrease (p < 0.05) in both SDHAF2 and SDHD mRNA expression, which may be suggestive of a pathogenic role. However, while SDHB protein expression as determined by IHC in a small cohort of tumors was lower in PCCs than in the surrounding adrenal cortex, there was no obvious correlation with LOH or the level of SDHAF2/SDHD mRNA expression. In addition, the lack of mutations and promoter methylation in the investigated samples indicates that other events on chromosome 11 might be involved in the development of PCCs in association with VHL syndrome.
World Journal of Surgery 12/2013; · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A third of patients with paraganglial tumors, pheochromocytoma and paraganglioma, carry germline mutations in one of the susceptibility genes, RET, VHL, NF1, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127 and MAX. Despite increasing importance, data for long-term prognosis are scarce in pediatric presentations. The European-American-Pheochromocytoma-Paraganglioma-Registry, with a total of 2001 patients with confirmed paraganglial tumors, was the platform for this study. Molecular genetic and phenotypic classification and assessment of gene-specific long-term outcome with second and/or malignant paraganglial tumors and life expectancy was performed in patients diagnosed <18 years. Of 177 eligible registrants, 80% had mutations, 49% VHL, 15% SDHB, 10% SDHD, 4% NF1 and one patient each in RET, SDHA and SDHC. A second primary paraganglial tumor developed in 38% with increasing frequency over time, reaching 50% at 30 years after initial diagnosis. Their prevalence was associated with hereditary disease (p=0.001), particularly in VHL and SDHD mutation carriers (VHL vs others, p=0.001, SDHD vs others, p=0.042). A total of 16 (9%) patients with hereditary disease had malignant tumors, 10 at initial diagnosis and another 6 during follow-up. The highest prevalence was associated with SDHB (SDHB vs others, p<0.001). Eight patients died (5%), all of whom had germline mutations. Mean life expectancy was 62 years with hereditary disease. Hereditary disease and the underlying germline mutation define the long-term prognosis of pediatric patients in terms of prevalence and time of second primaries, malignant transformation and survival. Based on these data, gene-adjusted, specific surveillance guidelines can help effective preventive medicine.
Endocrine Related Cancer 10/2013; · 5.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Head and neck paragangliomas, rare neoplasms of the paraganglia composed of nests of neurosecretory and glial cells embedded in vascular stroma, provide a remarkable example of organoid tumor architecture. To identify genes and pathways commonly deregulated in head and neck paraganglioma, we integrated high-density genome-wide copy number variation (CNV) analysis with microRNA and immunomorphological studies. Gene-centric CNV analysis of 24 cases identified a list of 104 genes most significantly targeted by tumor-associated alterations. The "NOTCH signaling pathway" was the most significantly enriched term in the list (P = 0.002 after Bonferroni or Benjamini correction). Expression of the relevant NOTCH pathway proteins in sustentacular (glial), chief (neuroendocrine) and endothelial cells was confirmed by immunohistochemistry in 47 head and neck paraganglioma cases. There were no relationships between level and pattern of NOTCH1/JAG2 protein expression and germline mutation status in the SDH genes, implicated in paraganglioma predisposition, or the presence/absence of immunostaining for SDHB, a surrogate marker of SDH mutations. Interestingly, NOTCH upregulation was observed also in cases with no evidence of CNVs at NOTCH signaling genes, suggesting altered epigenetic modulation of this pathway. To address this issue we performed microarray-based microRNA expression analyses. Notably 5 microRNAs (miR-200a,b,c and miR-34b,c), including those most downregulated in the tumors, correlated to NOTCH signaling and directly targeted NOTCH1 in in vitro experiments using SH-SY5Y neuroblastoma cells. Furthermore, lentiviral transduction of miR-200s and miR-34s in patient-derived primary tympano-jugular paraganglioma cell cultures was associated with NOTCH1 downregulation and increased levels of markers of cell toxicity and cell death. Taken together, our results provide an integrated view of common molecular alterations associated with head and neck paraganglioma and reveal an essential role of NOTCH pathway deregulation in this tumor type.
[Show abstract][Hide abstract] ABSTRACT: Background: The purpose of this study was to give an overview on hereditary syndromes associated with head and neck paragangliomas (HNPGs). Methods: Our methods were the review and discussion of the pertinent literature. Results: About one third of all HNPG patients are carriers of germ line mutations. Hereditary HNPG have been described in association with mutations of ten different genes. Mutations of the genes SDHD, SDHAF2, SDHC and SDHB are the cause of paraganglioma syndromes (PGLs) 1, 2, 3 and 4. SDHA, VHL and TMEM127 gene mutations also harbor the risk for HNPG development. HNPG in patients with RET, NF1, and MAX gene mutations have been described very infrequently. Conclusions: All patients with HNPG should be offered a molecular genetic screening. This screening may usually be restricted to mutations of the genes SDHD, SDHB and SDHC. Certain clinical parameters can help to set up the order in which those genes should be tested. Head Neck, 2013.
[Show abstract][Hide abstract] ABSTRACT: Sporadic and hereditary forms of renal cell carcinoma (RCC), von Hippel-Lindau (VHL) disease and the familial paraganglioma syndromes are closely related in terms of their clinical, molecular, and genetic aspects. Most RCCs occur sporadically and the heritable fraction of RCC is estimated to be just 2-4%. An understanding of the molecular genetic basis, the disease-specific and gene-specific biology and the clinical characteristics of these cancer syndromes is of utmost importance for effective genetic diagnosis and appropriate treatment. In addition, such insight will improve our understanding of sporadic RCCs. To date, 10 different heritable RCC syndromes have been described. VHL syndrome is the oldest known hereditary RCC syndrome. Similar to VHL disease, phaeochromocytoma is a major manifestation of the paraganglioma syndromes types 1, 3 and 4 in which RCCs have been reported. These syndromes are therefore regarded as VHL-related disorders and are included in this Review. Multifocal tumours, bilateral occurrence, a young age at diagnosis and/or family history are clinical red flags suggestive of hereditary disease and should trigger referral for genetic and molecular analysis. The identification of an underlying genetic alteration enables gene-specific risk assessment and opens up the possibility of a tailored follow-up strategy and specific surveillance protocols as the basis of effective preventive medicine. The important goals of preventive medicine are to increase the life expectancy of affected patients and to improve their quality of life. The study of seemingly rare hereditary syndromes and their susceptibility genes has consistently revealed clues regarding the aetiology and pathogenesis of these diseases, and can aid diagnosis and the development of therapeutics for patients affected by much more common sporadic counterparts.
[Show abstract][Hide abstract] ABSTRACT: Subarachnoid hemorrhage from ruptured intracranial aneurysms is associated with a severe prognosis. Preventive treatment of unruptured intracranial aneurysms is possible and recommended. However, the identification of risk patients by genetic analyses is not possible because of lack of candidate genes. Collagen type I α2 (COL1A2) has been associated with the presence of aneurysms in patients from Japan, China, and Korea. In this study, we investigate whether COL1A2 is a possible aneurysm candidate gene in the German population.
Patients admitted with intracranial aneurysms to our department and collaborating departments were enrolled. Three single-nucleotide polymorphisms (SNPs) of the COL1A2 gene, namely rs42524 in exon 28, rs1800238 in exon 32, and rs2621215 in intron 46 were investigated using restriction enzymes and sequencing. HapMap data were used for comparison of allelic frequencies with the normal population by χ(2) test to identify significant associations between genotypes and the presence of aneurysms.
Two hundred sixty-nine patients were enrolled into the study. There was a significant correlation with the presence of aneurysms for the GC allele of the SNP rs42524 in exon 28 (P = .02). The other polymorphisms did not show significant correlations.
The COL1A2 gene is associated with intracranial aneurysms in a subset of the German population. However, it is not responsible for the majority of aneurysms, and further candidate genes need to be identified to develop sensitive genetic screening for patients at risk.
Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 06/2013; · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: The role of autosomal dominant polycystic kidney disease (ADPKD) as a risk factor for renal cell carcinoma (RCC) is still under discussion. Data on prevalence of RCC in ADPKD are limited, especially on a large population scale. The aim of this study was to analyze the prevalence of RCC in ADPKD kidneys and characterize the clinical features of this coincidence. Methods: Based on our histopathological registry for ADPKD and the Else Kröner-Fresenius Registry, we retrospectively reviewed malignant and benign renal lesions in patients with ADPKD who had undergone renal surgery from 1988 to 2011. Results: 240 ADPKD patients underwent 301 renal surgeries. Mean age at surgery was 54 years. Overall, 16 malignant and 11 benign lesions were analyzed in 301 kidneys (5.3%; 3.7%), meaning that 12/240 (5%; 1:20) patients presented with malignant renal lesions. 66.7% (8/12) of these patients had undergone dialysis prior to surgery. We found 10/16 (63%) papillary RCC, 5/16 (31%) clear cell RCC, and 1/16 (6%) papillary noninvasive urothelial cancer. Regarding all renal lesions, 6/17 (35.3%) patients had more than one histological finding in their kidneys. In 2 cases, metachronous metastases were removed. Mean follow-up was 66.7 months. Conclusion: Kidney-related prevalence of RCC in ADPKD kidneys was surprisingly high. Whether or not this is due to chronic dialysis or due to the underlying disease is still speculative. Like other cystic renal diseases with an increased risk for RCC, the attending physician should be aware of the malignant potential of ADPKD, especially with concomitant dialysis.
Nephron Clinical Practice 06/2013; 123(1-2):13-21. · 1.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The rupture of intracranial aneurysms leads to subarachnoid hemorrhage, which is often associated with poor outcome. Preventive treatment of unruptured intracranial aneurysms is possible and recommended. However, the lack of candidate genes precludes identifying patients at risk by genetic analyses. We observed intracranial aneurysms in 2 patients with von Hippel-Lindau (VHL) disease and the known disease-causing mutation c.292T > C (p.Tyr98His) in the VHL tumor suppressor gene. This study investigates whether the VHL gene is a possible candidate gene for aneurysm formation. METHODS: Patients with intracranial aneurysms admitted to our department between 2006 and 2009 were enrolled. The peripheral leukocyte DNA of 200 patients was investigated for sequence variations in the VHL gene using denaturing high performance liquid chromatography. Peripheral leukocyte DNA of 100 randomly sampled probands was investigated as a control group. The allelic frequencies of sequence variations between both groups were compared using the Fisher exact test. RESULTS: Fourteen of 200 patients with intracranial aneurysms had sequence variations at 6 different loci in the VHL gene. In contrast, no sequence variations were identified in 100 probands in the control group (P = 0.0062). However, none of the single-sequence variations had a statistically significant difference in the allelic frequencies compared to the control group. CONCLUSIONS: There is accumulating evidence for a genetic basis of aneurysm development. Our investigations lead to the conclusion that the VHL gene is potentially involved in the formation of intracranial aneurysms in a subset of patients. Additional candidate genes need to be identified in order to develop sensitive genetic screening for at-risk patients.
Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 02/2013; · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The definitive universally accepted treatment for carotid body tumors (CBT) is surgery. The impact of surgery on cranial nerves and the carotid artery has often been underestimated. Alternatively, a few CBTs have been followed without treatment or irradiation. The goal of this study is to summarize the existing evidence concerning the efficacy and safety of surgery and external beam radiotherapy (EBRT) for CBT. Relevant articles were identified using strict criteria for systematic searches. Sixty-seven articles met the criteria which included 2,175 surgically treated patients. On the other hand, 17 articles including 127 patients treated with EBRT were found. Long-term control of the disease was obtained in 93.8 % of patients who received surgical treatment and in 94.5 % of the radiotherapy group. Surgery resulted in 483 (483/2,175 = 22.2 %) new cranial nerve permanent deficits, whereas in the EBRT group, no new deficits were recorded (p = 0.004). The common/internal carotid artery was resected in 271 (12.5 %) patients because of injury or tumor encasement, with immediate reconstruction in 212 (9.7 %) patients. Three percent (60) of patients developed a permanent stroke and 1.3 % (26) died due to postoperative complications. The major complications rates and the mortality after completion of the treatment also were significantly higher in surgical series compared to EBRT series. This systematic analysis highlights evidence that EBRT offers a similar chance of tumor control with lower risk of morbidity as compared to surgery in patients with CBT. This questions the traditional notion that surgery should be the mainstay of treatment.
Archives of Oto-Rhino-Laryngology 02/2013; · 1.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:: Neurogenic polyglobulia occurs with CNS hemangioblastomas. Among the suggested mechanisms are extramedullary hematopoiesis in the tumor tissue and germline mutations of the VHL tumor suppressor gene. OBJECTIVE:: To determine the frequency and driving mechanisms of polyglobulia in CNS hemangioblastomas. METHODS:: We performed a retrospective analysis of pre- and postoperative (at 3 and 12 months) hemoglobin levels in a consecutive series of patients with hemangioblastomas operated in our institution from 1996 to 2009. We performed molecular genetic analyses for mutations of the VHL tumor suppressor gene. RESULTS:: Preoperative hemoglobin levels were available from 164 patients. The average hemoglobin level (15.2 g/dl in males and 13.1 g/dl in females) was within normal range according to our standards. Of 22 patients with increased preoperative hemoglobin levels (>17 g/dl in males and >15 g/dl in females), 8 presented with pathological hemoglobin (>18.5 g/dl in males and >16.5 g/dl in females) according to WHO criteria. Surgical removal of the hemangioblastoma resulted in a permanent cure of polyglobulia in all patients. 6 of the 8 patients with pathological hemoglobin elevation carried a germline mutation of the VHL tumor suppressor gene. CONCLUSION:: Neurogenic polyglobulia occurs in a subset of patients with hemangioblastomas. This phenomenon is mostly observed in VHL mutations-carriers, but also occurs in patients with sporadic hemangioblastomas. Removal of the tumor results in permanent cure of polyglobulia. Our observations suggest that polyglobulia is an effect by the tumor itself, either due to paraneoplasia or extramedullary hematopoiesis.
[Show abstract][Hide abstract] ABSTRACT: Background
As we emerge into the genomic medicine era, the epidemiology of diseases is taken for granted. Accurate prevalence figures, especially of rare diseases (RDs, ≤50/100 000), will become even more important for purposes of health care and societal planning. We noticed that the numbers of affected individuals in regionally established registries for mainly hereditary RDs do not align with published estimated and expected prevalence figures. We therefore hypothesized that such non-population-based means overestimate RDs and sought to address this by recalculating prevalence for an important 'common' hereditary disease, autosomal-dominant polycystic kidney disease (ADPKD) whereby presumed-prevalence is 100-250/100 000Methods
The Else-Kroener-Fresenius-ADPKD-Study in south-west Germany with a population of 2 727 351 inhabitants was established with the cooperation of all nephrology centres. Furthermore, general practitioners, internists, urologists, human geneticists and neurosurgery centres were contacted with questionnaires for demographic, family and kidney function data. Germline-mutation screening of susceptibility genes PKD1 and PKD2 was offered. Official population data for 2010 were used for overall and kidney function-adjusted prevalence estimations.ResultsA total of 891 subjects, 658 index-cases and 233 relatives, aged 10-89 (mean 52), were registered, with >90% response rate, 398 by nephrologists and 493 by non-nephrologists. Molecular-genetic analyses contributed to confirmation of the diagnosis in 57%. The overall prevalence of ADPKD was 32.7/100 000 reaching a maximum of 57.3/100 000 in the 6th decade of life.Conclusions
Prevalence of ADPKD is overestimated by 2- to 5-fold and close to the limit of RDs which may be of broad clinical, logistic and policy implications.
[Show abstract][Hide abstract] ABSTRACT: SDH genes, encoding succinate dehydrogenase, act as tumor suppressor, linking mitochondrial dysfunction with tumorigenesis. Heterozygous germline mutations in SDHA, SDHB, SDHC, SDHD and in the assembly factor encoding gene SDHAF2 have all been shown to predispose to heritable endocrine neoplasias such as Pheochromocytomas and Paragangliomas called "PHEO-PGL syndrome". SDH genes mutations, in addition to deletions or truncations which are most likely pathogenic, often include missense substitutions which can be of uncertain significance. Unclassified missense substitutions may be difficult to interpret unless the cause-effect link between mutation and the disease is established by functional and in silico studies or by the familial segregation with the phenotype.Using the yeast model, here we report functional investigations on several missense SDH mutations found in patients affected by Pheochromocytoma or Paraganglioma. The aim of this study was to evaluate whether and to which extent the yeast model may be useful for establishing the pathological significance of missense SDH mutations in humans. The results of our study demonstrate that the yeast is a good functional model to validate the pathogenic significance of SDHB missense mutations while, for missense mutations in SDHC and SDHD genes, the model can be informative only when the variation involves a conserved residue in a conserved domain.
Human Molecular Genetics 11/2012; · 6.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose.Surgical management of autosomal dominant polycystic kidney disease (ADPKD) in patients awaiting renal transplantation is a challenging task.METHODS: From 1998 to 2009, a total of 100 consecutive renal transplantations with simultaneous unilateral nephrectomy were performed in 59 men and 41 women with ADPKD and end-stage renal failure. About 38% received kidney allografts from living donors. The ipsilateral polycystic kidney was removed at the time of renal transplantation. Immunosuppressive therapy was not modified. Cold ischaemia time was 155 (38-204 min) versus 910 min (95-2760 min) for living versus deceased donor transplantation. Mean weight of removed kidneys was 2002 g (414-8850 g). Mean follow-up was 3.0 years (0.8-10.0 years).RESULTS: Overall patient and graft survival were 97 and 96% at 1 year and 93 and 80% at 5 years, respectively. Serum creatinine at current follow-up was 1.49 (0.8-2.8) mg/dL. Surgical complications, which might be associated with simultaneous nephrectomy requiring re-operation, occurred in 12% (lymphocele 4%, hernia 4%, post-operative haematoma or bleeding 4%). None of the patients died peri-operatively.CONCLUSION: Renal transplantation with simultaneous unilateral nephrectomy in ADPKD is a reasonable procedure for patients suffering from massively enlarged native kidneys.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Radionuclide imaging of phaeochromocytomas (PCCs) and paragangliomas (PGLs) involves various functional imaging techniques and approaches for accurate diagnosis, staging and tumour characterization. The purpose of the present guidelines is to assist nuclear medicine practitioners in performing, interpreting and reporting the results of the currently available SPECT and PET imaging approaches. These guidelines are intended to present information specifically adapted to European practice. METHODS: Guidelines from related fields, issued by the European Association of Nuclear Medicine and the Society of Nuclear Medicine, were taken into consideration and are partially integrated within this text. The same was applied to the relevant literature, and the final result was discussed with leading experts involved in the management of patients with PCC/PGL. The information provided should be viewed in the context of local conditions, laws and regulations. CONCLUSION: Although several radionuclide imaging modalities are considered herein, considerable focus is given to PET imaging which offers high sensitivity targeted molecular imaging approaches.
European Journal of Nuclear Medicine 08/2012; · 4.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Paragangliomas and pheochromocytomas are genetically heterogeneous diseases. The purpose of this study was to determine the sensitivity and specificity of PET with 3,4-dihydroxy-6-(18)F-fluoro-L-phenylalanin ((18)F-DOPA) for the detection and staging of pheochromocytomas/paragangliomas. Furthermore, we assessed whether the genotypes of pheochromocytomas and paragangliomas correlate with the uptake of (18)F-DOPA.
We retrospectively analyzed 101 consecutive patients who underwent (18)F-DOPA PET or (18)F-DOPA PET/CT for known or suspected pheochromocytomas or paragangliomas. Maximum (18)F-DOPA tumor uptake was quantified relative to uptake in the liver.
Histopathology, cross-sectional imaging, and follow-up indicated the presence of paragangliomas and pheochromocytomas in 68 patients and the absence of a tumor in 33 patients. The average (18)F-DOPA uptake by paragangliomas and pheochromocytomas, expressed as a tumor-to-liver ratio, was 5.9 ± 5.2. There was no significant difference in uptake among patients with von Hippel Lindau syndrome (VHL; n = 19), succinate dehydrogenase B-D mutation (n = 21), neurofibromatosis type 1 (n = 1), RET (n = 1), no germline mutation (n = 20), or unknown mutation status (n = 6) (P = 0.84). All 8 patients with an SDHD mutation were true-positive on (18)F-DOPA PET. There were 2 cases of false-negative results each in the group with SDHB (2/12) and VHL mutations (2/19) and 1 false-negative result in the subgroup of patients with unknown mutation status (1/6). Overall, (18)F-DOPA PET yielded a sensitivity of 93% and a specificity of 88% for the detection of paragangliomas and pheochromocytomas on a patient basis (positive and negative predictive value, 94% and 85%, respectively).
(18)F-DOPA PET is a sensitive and specific imaging modality for the detection and staging of pheochromocytomas and paragangliomas in different genotypes, including VHL-, SDHB-, and SDHD-mutation carriers, and in patients with no germline mutation.
Journal of Nuclear Medicine 07/2012; 53(9):1352-8. · 5.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Systemic analysis of somatic mutations of other susceptibility genes in syndromic tumors as well as apparently sporadic tumors in well-characterized specimens is lacking. Its clinical relevance has not been studied. Our objective was to determine the frequency of second allele inactivation in syndromic tumors and determine the frequency and potential clinical impact of somatic mutations and loss of heterozygosity (LOH) of the known susceptibility genes in syndromic and sporadic tumors. Nine tumor specimens from clinically characterized VHL mutation, five from SDHB mutation, four from SDHD mutation, two from RET mutation carriers, and eight from apparently sporadic cases were analyzed. Tumor DNA mutation screening of the SDHx, VHL, and RET genes and LOH analyses of the SDHx and VHL genes were performed. The Yates-corrected chi-squared test was used for comparison of the clinical data and the molecular-genetic results. Second allele inactivation in tumors was identified in 83% of VHL, 80% of SDHB, and 50% of SDHD specimen. High prevalence of VHL (6/6, p=0.024) and SDHB (7/7, p=0.018) somatic mutations has been identified in the sporadic group compared to all others. In the group of the VHL tumors the SDHB somatic events were significantly lower (2/6; p=0.045). In 18/19 (95%) of cases, we were able to demonstrate the presence of at least two concomitant affected susceptibility genes. We conclude that LOH is the most prevalent second allele-inactivating event. SDHB and VHL somatic mutation might play a role in the sporadic forms of tumor development. There is no clinical impact of mutation screening or LOH analysis of tumor specimens.