Multidisciplinary integrated care pathway for von Hippel-Lindau disease.

BACKGROUND: Clinical pathways are care plans established to describe essential steps in the care of patients with a specific clinical problem. They translate (inter)national guidelines into local applicable protocols and clinical practice. The purpose of this article is to establish a multidisciplinary integrated care pathway for specialists and allied health care professionals in caring for individuals with von Hippel-Lindau (VHL) disease. METHODS: Using a modified Delphi consensus-making process, a multidisciplinary panel from 5 Dutch University Medical Centers produced an integrated care pathway relating to the provision of care for patients with VHL by medical specialists, specialized nurses, and associated health care professionals. Patient representatives cocreated the pathway and contributed quality criteria from the patients' perspective. RESULTS: The panel agreed on recommendations for the optimal quality of care for individuals with a VHL gene mutation. These items were the starting point for the development of a patient care pathway. With international medical guidelines addressing the different VHL-related disorders, this article presents a patient care pathway as a flowchart that can be incorporated into VHL expertise clinics or nonacademic treatment clinics. CONCLUSIONS: Medical specialists (internists, urologists, neurosurgeons, ophthalmologists, geneticists, medical oncologists, neurologists, gastroenterologists, pediatricians, and ear-nose-throat specialists) together with specialized nurses play a vital role alongside health care professionals in providing care to people affected by VHL and their families. This article presents a set of consensus recommendations, supported by organ-specific guidelines, for the roles of these practitioners in order to provide optimal VHL care. This care pathway can form the basis for the development of comprehensive, integrated pathways for multiple neoplasia syndromes.

Diagnostic Accuracy of Salivary Metanephrines in Pheochromocytomas and Paragangliomas.

BACKGROUND: Measurements of plasma free metanephrines are recommended for diagnosing pheochromocytomas and paragangliomas (PPGL). Metanephrines can be detected in saliva with LC-MS/MS with sufficient analytical sensitivity and precision. Because collecting saliva is noninvasive and less cumbersome than plasma or urine sampling, we assessed the diagnostic accuracy of salivary metanephrines in diagnosing PPGL. METHODS: This 2-center study included 118 healthy participants (44 men; mean age: 33 years (range: 19--74 years)), 44 patients with PPGL, and 54 patients suspected of PPGL. Metanephrines were quantified in plasma and saliva using LC-MS/MS. Diagnostic accuracy; correlation between plasma and salivary metanephrines; and potential factors influencing salivary metanephrines, including age, sex, and posture during sampling, were assessed. RESULTS: Salivary metanephrines were significantly higher in patients with PPGL compared with healthy participants (metanephrine (MN): 0.19 vs 0.09 nmol/L, P < 0.001; normetanephrine (NMN): 2.90 vs 0.49 nmol/L, P < 0.001). The diagnostic sensitivity and specificity of salivary metanephrines were 89% and 87%, respectively. Diagnostic accuracy of salivary metanephrines was 88%, with an area under the ROC curve of 0.880. We found a significant correlation between plasma and salivary metanephrines (Pearson correlation coefficient: MN, 0.86, P < 0.001; NMN, 0.83, P < 0.001). Salivary NMN concentrations were higher when collected in a seated position compared with supine (P < 0.001) and increased with age (P < 0.001). CONCLUSIONS: Salivary metanephrines are a promising tool in the biochemical diagnosis of PPGL. Salivary metanephrines correlate with plasma free metanephrines and are increased in patients with PPGL. At this time, however, salivary metanephrines cannot replace measurement of plasma free metanephrines.

Use of Salivary Iodine Concentrations to Estimate the Iodine Status of Adults in Clinical Practice.

BACKGROUND: Measurement of the 24-h urinary iodine concentration or urinary iodine excretion (UIE) is the gold standard to determine iodine status; however, this method is inconvenient. The use of salivary iodine could be a possible alternative since salivary glands express the sodium-iodine symporter. OBJECTIVES: We aimed to establish the correlation between the salivary iodine secretion and UIE, to evaluate the clinical applicability of the iodine saliva measurement. METHODS: We collected 24-h urine and saliva samples from 40 participants ≥18 y: 20 healthy volunteers with no specific diet (group 1), 10 patients with differentiated thyroid cancer with a low dietary intake (<50 µg/d, group 2), and 10 patients with a high iodine status as the result of the use of amiodarone (group 3). Urinary and salivary iodine were measured using a validated inductively coupled plasma MS method. To correct for differences in water content, the salivary iodine concentration (SIC) was corrected for salivary protein and urea concentrations (SI/SP and SI/SU, respectively). The intra- and inter-individual CVs were calculated, and the Kruskal-Wallis test and Spearman's correlation were used. RESULTS: The intra-individual CVs for SIC, SI/SP, and SI/SU were 63.8%, 37.7%, and 26.9%, respectively. The inter-individual CVs for SIC, SI/SP, and SI/SU were 77.5%, 41.6% and 47.0%, respectively. We found significant differences (P < 0.01) in urinary and salivary iodine concentrations between all groups [the 24-h UIE values were 176 µg/d (IQR, 96.1-213 µg/d), 26.0 µg/d (IQR, 22.0-37.0 µg/d), and 10.0*103 µg/d (IQR, 7.57*103-11.4*103 µg/d) in groups 1-3, respectively; the SIC values were 136 µg/L (IQR, 86.3-308 µg/L), 71.5 µg/L (IQR, 29.5-94.5 µg/L), and 14.3*103 µg/L (IQR, 10.6*103-25.6*103 µg/L) in groups 1-3, respectively]. Correlations between the 24-h UIE and SIC, SI/SP, and SI/SU values were strong (ρ = 0.80, ρ = 0.90, and ρ = 0.86, respectively; P < 0.01). CONCLUSIONS: Strong correlations were found between salivary and urinary iodine in adults with different daily iodine intakes. A salivary iodine measurement can be performed to assess the total iodine body pool, with the recommendation to correct for salivary protein or urea.

Health-Related Quality of Life in Patients with Multiple Endocrine Neoplasia Type 1.

INTRODUCTION: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary endocrine tumor syndrome characterized by the triad of primary hyperparathyroidism, duodenopancreatic neuroendocrine tumors (pNETs), and pituitary tumors. Patients are confronted with substantial morbidity and are consequently at risk for an impaired quality of life (QOL). Meticulous assessment of QOL and associated factors in a representative population is needed to understand the full spectrum of the burden of the disease. PATIENTS AND METHODS: A cross-sectional study was performed using the national Dutch MEN1 cohort. Patients with a confirmed MEN1 mutation received the SF-36 Health Related Quality of Life questionnaire and questions regarding sociodemographic and medical history. RESULTS: A total of 227 of 285 (80%) eligible MEN1 patients returned the questionnaires. Health-related QOL scores (HRQOL) in MEN1 patients were significantly lower for the majority of subscales of the SF-36 in comparison with the general Dutch population. The most consistent predictor for HRQOL was employment status, followed by the presence of a pituitary tumor. 16% of patients harboring a pNET and 29% of patients with a pituitary tumor according to the medical records, reported that they were unaware of such a tumor. These subgroups of patients had several significant better QOL scores than patients who were aware of their pNET or pituitary tumors. CONCLUSION: Patients with MEN1 have an impaired QOL in comparison with the general Dutch population warranting special attention within routine care. For daily practice, physicians should be aware of their patients' impaired QOL and of the impact of unemployment on QOL.

Clinical implications of the oncometabolite succinate in SDHx-mutation carriers.

Succinate dehydrogenase (SDH) mutations lead to the accumulation of succinate, which acts as an oncometabolite. Germline SDHx mutations predispose to paraganglioma (PGL) and pheochromocytoma (PCC), as well as to renal cell carcinoma and gastro-intestinal stromal tumors. The SDHx genes were the first tumor suppressor genes discovered which encode for a mitochondrial enzyme, thereby supporting Otto Warburg's hypothesis in 1926 that a direct link existed between mitochondrial dysfunction and cancer. Accumulation of succinate is the hallmark of tumorigenesis in PGL and PCC. Succinate accumulation inhibits several α-ketoglutarate dioxygenases, thereby inducing the pseudohypoxia pathway and causing epigenetic changes. Moreover, SDH loss as a consequence of SDHx mutations can lead to reprogramming of cell metabolism. Metabolomics can be used as a diagnostic tool, as succinate and other metabolites can be measured in tumor tissue, plasma and urine with different techniques. Furthermore, these pathophysiological characteristics provide insight into therapeutic targets for metastatic disease. This review provides an overview of the pathophysiology and clinical implications of oncometabolite succinate in SDHx mutations.

Blood sampling for metanephrines comparing venipuncture vs. indwelling intravenous cannula in healthy subjects.

Background To diagnose pheochromocytoma or sympathetic paraganglioma, guidelines recommend blood sampling after at least 30 min of supine rest and using an indwelling intravenous cannula is preferred. Although blood sampling by venipuncture is more convenient and cost-effective, it is unknown whether venipuncture affects plasma concentrations of free metanephrines (MNs). We therefore investigated whether there is a difference in plasma concentrations of free MNs collected by venipuncture or by an intravenous cannula. Methods We included 22 healthy participants (12 men and 10 women, median age 26 years). We collected blood using an indwelling cannula and venipuncture to determine plasma concentrations of free MNs and catecholamines, and calculated the median of the individually calculated absolute and relative differences. Results Plasma concentrations of free MN, normetanephrine (NMN) and epinephrine were higher with blood sampling using venipuncture compared to that when using an indwelling cannula. The median (interquartile range [IQR]) difference was MN 0.020 (-0.004 to 0.040) nmol/L, median percentage difference 20.5% (-2.4 to 35.2%), NMN 0.019 (-0.004 to 0.077) nmol/L, median percentage difference 4.6% (-1.1 to 25.4%) and epinephrine 0.022 (0.007-0.079) nmol/L, median percentage difference 24.9% (7.8-83.3%). When the two sampling conditions were compared, plasma-free 3-methoxytyramine (3-MT), norepinephrine and dopamine concentrations did not differ. Conclusions Blood sampling by venipuncture resulted in statistically significant higher concentrations of MN, NMN and epinephrine compared to sampling by means of an indwelling cannula. However, differences were small. For most patients it seems justifiable to collect blood via venipuncture.

Adrenal tracer uptake by 18F-FDOPA PET/CT in patients with pheochromocytoma and controls.

CONTEXT: 18F-FDOPA PET/CT accurately localizes pheochromocytoma in patients with an established biochemical diagnosis. However, cut-off 18F-FDOPA levels of standardized uptake values (SUVmax) for both normal adrenal glands and pheochromocytoma are lacking. OBJECTIVE: Objectives of this study were to determine (1) reference maximum standardized uptake values (SUVmax) for normal adrenal 18F-DOPA tracer uptake and (2) the optimal diagnostic approach for pheochromocytoma localization by using 18F-DOPA SUVmax across a series of cut-off points: the affected adrenal gland (inter-individual analysis), the difference in SUVmax between the affected adrenal gland and the contralateral normal adrenal gland (intra-individual analysis), or a combination of these two. PATIENTS AND METHODS: All patients with histologically confirmed pheochromocytoma diagnosed at our center between November 2009 and December 2017 were retrospectively analysed. Only those patients who underwent an 18F-FDOPA PET/CT-scan for localization purposes before adrenalectomy were included for further analysis. The control group consisted of patients who underwent 18F-FDOPA PET/CT for other indications and who had no genetic susceptibility for developing a pheochromocytoma. SUVmax of the volume of interest surrounding the adrenal glands was determined on EARL reconstructed images. Receiver operating characteristic (ROC) analysis was performed for adrenal gland SUVmax and intra-individual difference in SUVmax between affected and normal adrenal gland. In addition, binary logistic regression was performed for ROC analysis of the combined parameters. RESULTS: In total, 47 histologically confirmed pheochromocytomas were diagnosed in 45 patients, and 245 disease control patients were identified. In the control group, no statistical differences between the SUVmax of left and right adrenal glands were observed, and uptake values in both adrenal glands correlated significantly with each other (r = 0.865, p < 0.001). Median (range) adrenal gland SUVmax in pheochromocytomas and in the control group was 12 (2.6-50) and 2.9 (1.1-6.6), respectively (p < 0.001). ROC analysis revealed 93% sensitivity and 85% specificity at an SUVmax cut-off value of 4.1 (area under the curve (AUC) = 0.951), and 93% sensitivity and 96% specificity at an intra-individual SUVmax difference between the affected and normal adrenal gland of 1.0 (AUC = 0.992). The combination of both variables increased the AUC to 0.995. CONCLUSIONS: 18F-FDOPA PET/CT distinguishes pheochromocytoma from normal adrenal glands with the highest diagnostic accuracy when combining the SUVmax of the affected adrenal gland with the difference in SUVmax between affected and normal adrenal gland.

Prognostic factors and survival in MEN1 patients with gastrinomas: Results from the DutchMEN study group (DMSG).

BACKGROUND AND OBJECTIVES: Gastrinomas are the most prevalent functioning neuroendocrine tumors (NET) in multiple endocrine neoplasia type 1 (MEN1). Guidelines suggest medical therapy in most patients, but surgery may be considered in a subgroup. Currently, factors to guide management are necessary. This population-based cohort study assessed prognostic factors of survival in patients with MEN1-related gastrinomas. METHODS: Patients with MEN1 having gastrinomas were identified in the Dutch MEN1 database from 1990 to 2014 based on fasting serum gastrin (FSG) levels and/or pathology. Predictors of overall survival were assessed using Cox regression. RESULTS: Sixty-three patients with gastrinoma (16% of the MEN1 population) were identified. Five- and 10-year overall survival rates were 83% and 65%, respectively. Prognostic factors associated with overall survival were initial FSG levels ≥20x upper limit of normal (ULN) (hazard ratio [HR], 6.2 [95% confidence interval, 1.7-23.0]), pancreatic NET ≥2 cm (HR 4.5; [1.5-13.1]), synchronous liver metastases (HR 8.9; [2.1-36.7]), gastroduodenoscopy suspicious for gastric NETs (HR 12.7; [1.4-115.6]), and multiple concurrent NETs (HR 5.9; [1.2-27.7]). CONCLUSION: Life expectancy of patients with MEN1 gastrinoma is reduced. FSG levels and pancreatic NETs ≥2 cm are prognostic factors. FSG levels might guide surveillance intensity, step-up to additional diagnostics, or provide arguments in selecting patients who might benefit from surgery.

Management of MEN1 Related Nonfunctioning Pancreatic NETs: A Shifting Paradigm: Results From the DutchMEN1 Study Group.

OBJECTIVE: To assess if surgery for Multiple Endocrine Neoplasia type 1 (MEN1) related nonfunctioning pancreatic neuroendocrine tumors (NF-pNETs) is effective for improving overall survival and preventing liver metastasis. BACKGROUND: MEN1 leads to multiple early-onset NF-pNETs. The evidence base for guiding the difficult decision who and when to operate is meager. METHODS: MEN1 patients diagnosed with NF-pNETs between 1990 and 2014 were selected from the DutchMEN1 Study Group database, including > 90% of the Dutch MEN1 population. The effect of surgery was estimated using time-dependent Cox analysis with propensity score restriction and adjustment. RESULTS: Of the 152 patients, 53 underwent surgery and 99 were managed by watchful waiting. In the surgery group, tumors were larger and faster-growing, patients were younger, more often male, and were more often treated in centers that operated more frequently. Surgery for NF-pNETs was not associated with a significantly lower risk of liver metastases or death, [adjusted hazard ratio (HR) = 0.73 (0.25-2.11)]. Adjusted HR's after stratification by tumor size were: NF-pNETs <2 cm = 2.04 (0.31-13.59) and NF-pNETs 2-3 cm = 1.38 (0.09-20.31). Five out of the 6 patients with NF-pNETs >3 cm managed by watchful waiting developed liver metastases or died compared with 6 out of the 16 patients who underwent surgery. CONCLUSIONS: MEN1 patients with NF-pNETs <2 cm can be managed by watchful waiting, hereby avoiding major surgery without loss of oncological safety. The beneficial effect of a surgery in NF-pNETs 2 to 3 cm requires further research. In patients with NF-pNETs >3 cm, watchful waiting seems not advisable.

Emerging role of dopamine in neovascularization of pheochromocytoma and paraganglioma.

Dopamine is a catecholamine that acts both as a neurotransmitter and as a hormone, exerting its functions via dopamine (DA) receptors that are present in a broad variety of organs and cells throughout the body. In the circulation, DA is primarily stored in and transported by blood platelets. Recently, the important contribution of DA in the regulation of angiogenesis has been recognized. In vitro and in vivo studies have shown that DA inhibits angiogenesis through activation of the DA receptor type 2. Overproduction of catecholamines is the biochemical hallmark of pheochromocytoma (PCC) and paraganglioma (PGL). The increased production of DA has been shown to be an independent predictor of malignancy in these tumors. The precise relationship underlying the association between DA production and PCC and PGL behavior needs further clarification. Herein, we review the biochemical and physiologic aspects of DA with a focus on its relations with VEGF and hypoxia inducible factor related angiogenesis pathways, with special emphasis on DA producing PCC and PGL.-Osinga, T. E., Links, T. P., Dullaart, R. P. F., Pacak, K., van der Horst-Schrivers, A. N. A., Kerstens, M. N., Kema, I. P. Emerging role of dopamine in neovascularization of pheochromocytoma and paraganglioma.

Impact of the Introduction of Calcimimetics on Timing of Parathyroidectomy in Secondary and Tertiary Hyperparathyroidism.

BACKGROUND: Hyperparathyroidism (HPT), both secondary and tertiary, is common in patients with end-stage renal disease, and is associated with severe bone disorders, cardiovascular complications, and increased mortality. Since the introduction of calcimimetics in 2004, treatment of HPT has shifted from surgery to predominantly medical therapy. OBJECTIVE: The aim of this study was to evaluate the impact of this change of management on the HPT patient population before undergoing (sub-)total parathyroidectomy (PTx). METHODS: Overall, 119 patients with secondary or tertiary HPT undergoing PTx were included in a retrospective, single-center cohort. Group A, who underwent PTx before January 2005, was compared with group B, who underwent PTx after January 2005. Patient characteristics, time interval between HPT diagnosis and PTx, and postoperative complications were compared. RESULTS: Group A comprised 70 (58.8 %) patients and group B comprised 49 (41.2 %) patients. The median interval between HPT diagnosis and PTx was 27 (interquartile range [IQR] 12.5-48.0) and 49 (IQR 21.0-75.0) months for group A and B, respectively (p = 0.007). Baseline characteristics were similar among both groups. The median preoperative serum parathyroid hormone (PTH) level was 936 pg/mL (IQR 600-1273) for group A versus 1091 pg/mL (IQR 482-1373) for group B (p = 0.38). PTx resulted in a dramatic PTH reduction (less than twofold the upper limit: A, 80.0 %; B, 85.4 %), and postoperative complication rates were low in both groups (A: 7.8 %; B: 10.2 %) [p = 0.66]. CONCLUSIONS: The introduction of calcimimetics in 2004 is associated with a significant 2-year delay of surgery with continuously elevated preoperative PTH levels, while parathyroid surgery, even in a fragile population, is considered a safe and effective procedure.

Additional value of a high sensitive thyroglobulin assay in the follow-up of patients with differentiated thyroid carcinoma.

OBJECTIVE: Thyroglobulin (Tg) is an excellent tumour marker, as detectable or increasing Tg levels are highly indicative of persistent or recurrent differentiated thyroid carcinoma (DTC). The clinical value of a highly sensitive (hs)-Tg assay in patients with DTC has not yet been established. The aim of this study was to investigate the additional value of unstimulated hs-Tg measurements (Tg-on) compared to stimulated IRMA-Tg measurements (Tg-off) in the follow-up of patients with DTC. DESIGN, PATIENTS, MEASUREMENTS: We retrospectively studied patients treated for DTC between 2006 and 2013 and compared hs-Tg and IRMA-Tg measurements. The study group consisted of 99 DTC patients in remission; Tg-on was measured 3 months after remnant ablation and Tg-off 6 months after ablation. RESULTS: In the study group, 44 patients showed a hs-Tg-on <0·15 µg/l (functional sensitivity); of these, 43 had an IRMA-Tg-off measurement <1·0 µg/l, resulting in a negative predictive value of 97·7% and a positive predictive value of 56·4%. CONCLUSIONS: The hs-Tg-on measurement is able to predict patients with an IRMA-Tg-off <1·0 µg/l, and therefore decreases the need for Tg stimulation after ablation.

Prognostic value of WHO grade in pancreatic neuro-endocrine tumors in Multiple Endocrine Neoplasia type 1: Results from the DutchMEN1 Study Group.

BACKGROUND: The prognostic value of WHO grade in pancreatic neuroendocrine tumors (PanNETs) in patients with Multiple Endocrine Neoplasia Type 1 (MEN1) is unknown. METHODS: We performed a cohort study using the Dutch National MEN1 database, which includes >90% of the Dutch MEN1 population with data collected between 1990 and 2014. Formalin-fixed paraffin embedded tissue blocks from the largest resected PanNET per patient were collected. MIB1 staining was performed and KI67 labeling index (LI) was determined by manual eye-counting under a microscope and by digital image analysis. Mitotic count was evaluated from hematoxylin & eosin stains. Association between WHO grade and (time until) development of liver metastases was calculated. RESULTS: Sixty-nine MEN1 patients who underwent pancreatic surgery were included. Ten patients (14%) developed liver metastases and all had PanNETs ≥3 cm. WHO G1, G2 and G3 PanNETs were seen in 83% (n = 57), 16% (n = 11) and 1% (n = 1) respectively. In non-functioning PanNETs >2 cm, liver metastases occurred in 80% of WHO G2 PanNETs (4/5) compared to 23% (5/22) in WHO G1 PanNETs (p = 0.03) when WHO grade was based on mitotic count only. This significant association was not seen for WHO grade based on Ki67 LI. After five years, liver metastases in non-functioning PanNETs were not seen in tumors ≤2 cm, in 10% of the large WHO G1 (according to mitotic count only) tumors and in 60% of large WHO G2 tumors (p-value 0.000). CONCLUSION: High mitotic count is correlated with poor prognosis in MEN1 patients with large non-functioning PanNETs.

PROGNOSTIC FACTORS FOR SURVIVAL OF MEN1 PATIENTS WITH DUODENOPANCREATIC TUMORS METASTATIC TO THE LIVER: RESULTS FROM THE DMSG.

OBJECTIVE: Duodenopancreatic neuroendocrine tumors (DP-NETs) develop in a majority of patients with multiple endocrine neoplasia type 1 (MEN1) and are the leading cause of death. Overall survival (OS) and prognostic factors for patients with liver metastases from DP-NETs are not known. METHODS: This was a cohort study using the Dutch National MEN1 database, which includes >90% of the Dutch MEN1 population treated between 1990 and 2014. OS was assessed with time to event analysis, and prognostic factors were evaluated. RESULTS: A total of 56% of the MEN1 patients (n = 220) were diagnosed with a DP-NET, of who 34 (15%) developed DP-NET liver metastases. Median age at liver metastases diagnosis was 53 years (range 31-74). Of those patients, 16 patients (47%) had died after a median follow-up of 4 years (range 0.3-12.3). OS at 2, 5, and 10 years were 91%, 65%, and 50%, respectively. A trend towards worse survival was seen in males compared to females (5-year OS 58% versus 75%, P = .07) and also in patients with multiple liver metastases compared to patients with solitary liver metastasis (59 versus 83%, P = .09). CONCLUSION: Despite the fairly indolent course of DP-NET liver metastases in MEN1 patients, half of the population was deceased after 10 years. Sex and tumor load at diagnosis of liver metastases are possible prognostic factors for worse survival. ABBREVIATIONS: DMSG = DutchMEN1 Study Group; D-NET = duodenal neuroendocrine tumor; DP-NET = duodenopancreatic neuroendocrine tumor; HPF = high-power field; Ki67 LI = Ki67 labeling index; MEN1 = multiple endocrine neoplasia type 1; NET = neuroendocrine tumor; OS = overall survival; P-NET = pancreatic neuroendocrine tumor; PPI = proton pump inhibitor; ULN = upper limit of normal; WHO = World Health Organization.

Localization of parathyroid adenomas using 11C-methionine pet after prior inconclusive imaging.

PURPOSE: Minimally invasive parathyroidectomy (MIP) is the recommended treatment in primary hyperparathyroidism (pHPT) for which accurate preoperative localization is essential. The current imaging standard consists of cervical ultrasonography (cUS) and MIBI-SPECT/CT. 11C-MET PET/CT has a higher resolution than MIBI-SPECT/CT. The aim of this study was to determine the diagnostic performance of 11C-MET PET/CT after initial inconclusive or negative localization. METHODS: We performed a retrospective single center cohort study of patients with pHPT undergoing parathyroid surgery after prior negative imaging and later localization by means of 11C-MET PET/CT between 2006 and 2014. Preoperative localization by 11C-MET PET/CT was compared with later surgical localization, intraoperative quick PTH (IOPTH), duration of surgery, histopathology, and follow-up data. Also, differences in duration of surgery between the groups with and without correct preoperative localization were analyzed. RESULTS: In 18/28 included patients a positive 11C-MET-PET/CT result corresponded to the surgical localized adenoma (64%). In 3/28 patients imaging was false positive and no adenoma was found. In 7/28 patients imaging was false negative at the side of the surgically identified adenoma. Sensitivity of 11C-MET PET/CT was 72% (18/25). Duration of surgery of correctly localized patients was significantly shorter compared to falsely negative localized patients (p = 0.045). CONCLUSION: In an intention to treat 11C-MET-PET/CT correctly localized the parathyroid adenoma in 18/28 (64%) patients, after previous negative imaging. A preoperatively correct localized adenoma leads to a more focused surgical approach (MIP) potentially reducing duration of surgery and potentially healthcare costs.

MEN1 redefined, a clinical comparison of mutation-positive and mutation-negative patients.

BACKGROUND: Multiple Endocrine Neoplasia type 1 (MEN1) is diagnosed when two out of the three primary MEN1-associated endocrine tumors occur in a patient. Up to 10-30 % of those patients have no mutation in the MEN1 gene. It is unclear if the phenotype and course of the disease of mutation-negative patients is comparable with mutation-positive patients and if these patients have true MEN1. The present study aims to describe and compare the clinical course of MEN1 mutation-negative patients with two out of the three main MEN1 manifestations and mutation-positive patients during long-term follow-up. METHODS: This is a cohort study performed using the Dutch MEN1 database, including > 90 % of the Dutch MEN1 population. RESULTS: A total of 293 (90.7 %) mutation-positive and 30 (9.3 %) mutation-negative MEN1 patients were included. Median age of developing the first main MEN1 manifestation was higher in mutation-negative patients (46 vs. 33 years) (P = 0.007). Mutation-negative patients did not develop a third main MEN1 manifestation in the course of follow-up compared to 48.3 % of mutation-positive patients (P < 0.001). Median survival in mutation-positive patients was estimated at 73.0 years (95 % CI, 69.5-76.5) compared to 87.0 years (95 % CI not available) in mutation-negative patients (P = 0.001). CONCLUSIONS: Mutation-positive and mutation-negative MEN1 patients have a different phenotype and clinical course. Mutation-negative patients develop MEN1 manifestations at higher age and have a life expectancy comparable with the general population. The apparent differences in clinical course suggest that MEN1 mutation-negative patients do not have true MEN1, but another MEN1-like syndrome or sporadic co-incidence of two neuro-endocrine tumors.

Dopamine concentration in blood platelets is elevated in patients with head and neck paragangliomas.

BACKGROUND: Plasma 3-methoxytyramine (3-MT), a metabolite of dopamine, is elevated in up to 28% of patients with head and neck paragangliomas (HNPGLs). As free dopamine is incorporated in circulating platelets, we determined dopamine concentration in platelets in patients with a HNPGL. METHODS: A single center cohort study was performed between 2012 and 2014. Thirty-six patients with a HNPGL were compared to healthy controls (68 for dopamine in platelets and 120 for plasma 3-MT). RESULTS: Dopamine concentration in platelets was elevated in HNPGL patients compared to healthy controls (median [interquartile ranges] 0.48 [0.32-0.82] pmol/109 platelets vs. 0.31 [0.24-0.47] pmol/109 platelets; p<0.05), whereas plasma 3-MT concentration did not differ between both groups (0.06 [0.06-0.08] nmol/L vs. 0.06 [0.06-0.06] nmol/L; p=0.119). Based on 68 healthy controls, the reference interval for dopamine concentration in platelets was 0.12-0.97 pmol/109 platelets. Six (16.7%) patients with a HNPGL demonstrated an increased dopamine concentration in platelets compared to three (8.3%) patients with an increased plasma 3-MT level (p=0.053). The sensitivity and specificity were 16.7% and 98.5% for platelet dopamine and 8.3% and 97.5% for plasma 3-MT concentration (p=0.37). CONCLUSIONS: Dopamine concentration in platelets is elevated in patients with a HNPGL compared to healthy subjects, and may be a novel biomarker for dopamine producing paraganglioma.

Catecholamine-Synthesizing Enzymes Are Expressed in Parasympathetic Head and Neck Paraganglioma Tissue.

BACKGROUND/AIM: Increased dopamine production may be a feature of head and neck paraganglioma (HNPGL). 18F-fluorodihydroxyphenylalanine positron emission tomography scintigraphy has a high sensitivity for detecting HNPGLs. These observations strongly suggest that HNPGLs have the capacity for L-3,4-dihydroxyphenylalanine uptake and conversion towards dopamine. Therefore, our aim was to demonstrate the presence of catecholamine-synthesizing enzymes, i.e. tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC) and dopamine ß-hydroxylase (DBH) in HNPGL tissue. METHODS: A single-center study was performed among patients who underwent surgery for HNPGL at a single university referral center between 1994 and 2012. HNPGL tissue was immunohistochemically stained for TH, AADC and DBH. Data on paraganglioma-associated germline mutations, preoperative biochemical phenotype and imaging studies were retrieved. Catecholamine excess was defined as preoperative plasma and/or urinary levels of metanephrine, normetanephrine or 3-methoxytyramine above the upper reference limit. RESULTS: Nineteen HNPGLs from 18 patients were evaluated. All tumor tissues (100%) stained positive for AADC, 6 (32%) for TH and 2 (11%) for DBH. Of 3 HNPGLs staining positive for DBH, 2 were also positive for AADC and TH. Catecholamine excess was only present in 1 patient (5%). The HNPGLs of this single patient only showed positive staining for AADC. CONCLUSIONS: Catecholamine-synthesizing enzymes, in particular AADC, are expressed in the majority of HNPGL tissues.

Effect of metformin on left ventricular function after acute myocardial infarction in patients without diabetes: the GIPS-III randomized clinical trial.

IMPORTANCE: Metformin treatment is associated with improved outcome after myocardial infarction in patients with diabetes. In animal experimental studies metformin preserves left ventricular function. OBJECTIVE: To evaluate the effect of metformin treatment on preservation of left ventricular function in patients without diabetes presenting with ST-segment elevation myocardial infarction (STEMI). DESIGN, SETTING, AND PARTICIPANTS: Double-blind, placebo-controlled study conducted among 380 patients who underwent primary percutaneous coronary intervention (PCI) for STEMI at the University Medical Center Groningen, The Netherlands, between January 1, 2011, and May 26, 2013. INTERVENTIONS: Metformin hydrochloride (500 mg) (n = 191) or placebo (n = 189) twice daily for 4 months. MAIN OUTCOMES AND MEASURES: The primary efficacy measure was left ventricular ejection fraction (LVEF) after 4 months, assessed by magnetic resonance imaging. A secondary efficacy measure was the N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration after 4 months. The incidence of major adverse cardiac events (MACE; the combined end point of death, reinfarction, or target-lesion revascularization) was recorded until 4 months as a secondary efficacy measure. RESULTS: At 4 months, all patients were alive and none were lost to follow-up. LVEF was 53.1% (95% CI, 51.6%-54.6%) in the metformin group (n = 135), compared with 54.8% (95% CI, 53.5%-56.1%) (P = .10) in the placebo group (n = 136). NT-proBNP concentration was 167 ng/L in the metformin group (interquartile range [IQR], 65-393 ng/L) and 167 ng/L in the placebo group (IQR, 74-383 ng/L) (P = .66). MACE were observed in 6 patients (3.1%) in the metformin group and in 2 patients (1.1%) in the placebo group (P = .16). Creatinine concentration (79 µmol/L [IQR, 70-87 µmol/L] vs 79 µmol/L [IQR, 72-89 µmol/L], P = .61) and glycated hemoglobin (5.9% [IQR, 5.6%-6.1%] vs 5.9% [IQR, 5.7%-6.1%], P = .15) were not significantly different between both groups. No cases of lactic acidosis were observed. CONCLUSIONS AND RELEVANCE: Among patients without diabetes presenting with STEMI and undergoing primary PCI, the use of metformin compared with placebo did not result in improved LVEF after 4 months. The present findings do not support the use of metformin in this setting. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01217307.