Publications by authors named "Wim Sluiter"

134 Publications

Calcitonin testing for detection of medullary thyroid cancer in people with thyroid nodules.

Cochrane Database Syst Rev 2020 03 16;3:CD010159. Epub 2020 Mar 16.

University of Groningen, University Medical Center Groningen, Department of Endocrinology, Hanzeplein 1, Groningen, Netherlands, 9713 GZ.

Background: Thyroid nodules are very common in general medical practice, but rarely turn out to be a medullary thyroid carcinoma (MTC). Calcitonin is a sensitive tumour marker for the detection of MTC (basal calcitonin). Sometimes a stimulation test is used to improve specificity (stimulated calcitonin). Although the European Thyroid Association's guideline advocates calcitonin determination in people with thyroid nodules, the role of routine calcitonin testing in individuals with thyroid nodules is still questionable.

Objectives: The objective of this review was to determine the diagnostic accuracy of basal and/or stimulated calcitonin as a triage or add-on test for detection of MTC in people with thyroid nodules.

Search Methods: We searched CENTRAL, MEDLINE, Embase and Web of Science from inception to June 2018.

Selection Criteria: We included all retrospective and prospective cohort studies in which all participants with thyroid nodules had undergone determination of basal calcitonin levels (and stimulated calcitonin, if performed).

Data Collection And Analysis: Two review authors independently scanned all retrieved records. We extracted data using a standard data extraction form. We assessed risk of bias and applicability using the QUADAS-2 tool. Using the hierarchical summary receiver operating characteristic (HSROC) model, we estimated summary curves across different thresholds and also obtained summary estimates of sensitivity and specificity at a common threshold when possible.

Main Results: In 16 studies, we identified 72,368 participants with nodular thyroid disease in whom routinely calcitonin testing was performed. All included studies performed the calcitonin test as a triage test. Median prevalence of MTC was 0.32%. Sensitivity in these studies ranged between 83% and 100% and specificity ranged between 94% and 100%. An important limitation in 15 of the 16 studies (94%) was the absence of adequate reference standards and follow-up in calcitonin-negative participants. This resulted in a high risk of bias with regard to flow and timing in the methodological quality assessment. At the median specificity of 96.6% from the included studies, the estimated sensitivity (95% confidence interval (CI)) from the summary curve was 99.7% ( 68.8% to 100%). For the median prevalence of MTC of 0.23%, the positive predictive value (PPV) for basal calcitonin testing at a threshold of 10 pg/mL was 7.7% (4.9% to 12.1%). Summary estimates of sensitivity and specificity for the threshold of 10 pg/mL of basal calcitonin testing was 100% (95% CI 99.7 to 100) and 97.2% (95% CI 95.9 to 98.6), respectively. For combined basal and stimulated calcitonin testing, sensitivity ranged between 82% and 100% with specificity between 99% and 100%. The median specificity was 99.8% with an estimated sensitivity of 98.8% (95% CI 65.8 to 100) .

Authors' Conclusions: Both basal and combined basal and stimulated calcitonin testing have a high sensitivity and specificity. However, this may be an overestimation due to high risk of bias in the use and choice of reference standard The value of routine testing in patients with thyroid nodules remains questionable, due to the low prevalence, which results in a low PPV of basal calcitonin testing. Whether routine calcitonin testing improves prognosis in MTC patients remains unclear.
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http://dx.doi.org/10.1002/14651858.CD010159.pub2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7075519PMC
March 2020

The incidence of consecutive manifestations in Von Hippel-Lindau disease.

Fam Cancer 2019 07;18(3):369-376

Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Von Hippel-Lindau (VHL) disease is an autosomal dominant rare tumor syndrome characterized by high penetrance. VHL mutation carriers develop numerous manifestations in multiple organs during life. The natural course of development of new and growth of existing VHL-related manifestations is still unclear. In this study we aimed to gain insight into the development of subsequent manifestations in VHL disease. We retrospectively scored each new VHL-related manifestation as detected by standard follow-up (retina, central nervous system, kidneys and pancreas, excluding adrenal and endolymfatic sac manifestations) in 75 VHL mutation carriers. The Kaplan-Meier method was used to plot the cumulative proportions of all consecutive manifestations in each organ against age. The cumulative average number of manifestations in all organs during life was calculated by summating these cumulative proportions. Poisson model parameters were used to calculate average time to the detection of consecutive VHL manifestations in each organ. Consecutive VHL-related kidney and retina manifestations during life occur linearly according to Poisson distribution model. The total number of VHL manifestations rises linearly, with an average of seven VHL-related lesions at age 60 years. The incidence of consecutive VHL-related manifestations is constant during life in VHL mutation carriers. Our data is consistent with the notion that somatic inactivation of the remaining allele (Knudson's "two-hit" hypothesis) is the determining factor in developing new VHL-related manifestations.
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http://dx.doi.org/10.1007/s10689-019-00131-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560011PMC
July 2019

Mapping heterogeneity in glucose uptake in metastatic melanoma using quantitative F-FDG PET/CT analysis.

EJNMMI Res 2018 Nov 20;8(1):101. Epub 2018 Nov 20.

Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB, Groningen, The Netherlands.

Background: Metastatic melanoma patients can have durable responses to systemic therapy and even long-term survival. However, a large subgroup of patients does not benefit. Tumour metabolic alterations may well be involved in the efficacy of both targeted and immunotherapy. Knowledge on in vivo tumour glucose uptake and its heterogeneity in metastatic melanoma may aid in upfront patient selection for novel (concomitant) metabolically targeted therapies. The aim of this retrospective study was to provide insight into quantitative F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) parameters and corresponding intra- and inter-patient heterogeneity in tumour F-FDG uptake among metastatic melanoma patients. Consecutive, newly diagnosed stage IV melanoma patients with a baseline F-FDG PET/CT scan performed between May 2014 and December 2015 and scheduled to start first-line systemic treatment were included. Volume of interests (VOIs) of all visible tumour lesions were delineated using a gradient-based contour method, and standardized uptake values (SUVs), metabolically active tumour volume (MATV) and total lesion glycolysis (TLG) were determined on a per-lesion and per-patient basis. Differences in quantitative PET parameters were explored between patient categories stratified by BRAF and RAS mutational status, baseline serum lactate dehydrogenase (LDH) levels and tumour programmed death-ligand 1 (PD-L1) expression.

Results: In 64 patients, 1143 lesions ≥ 1 ml were delineated. Median number of lesions ≥ 1 ml was 6 (range 0-168), median maximum SUV 9.5 (range 0-58), median total MATV 29 ml (range 0-2212) and median total TLG 209 (range 0-16,740). Per-patient analysis revealed considerable intra- and inter-patient heterogeneity. Maximum SUVs, MATV, number of lesions and TLG per patient did not differ when stratifying between BRAF or RAS mutational status or PD-L1 expression status, but were higher in the patient group with elevated LDH levels (> 250 U/l) compared to the group with normal LDH levels (P < 0.001). A subset of patients with normal LDH levels also showed above median tumour F-FDG uptake.

Conclusions: Baseline tumour F-FDG uptake in stage IV melanoma is heterogeneous, independent of mutational status and cannot be fully explained by LDH levels. Further investigation of the prognostic and predictive value of quantitative F-FDG PET parameters is of interest.
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http://dx.doi.org/10.1186/s13550-018-0453-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6246760PMC
November 2018

Postoperative use of somatostatin analogs and mortality in patients with acromegaly.

Eur J Endocrinol 2019 Jan;180(1):1-9

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Objective To assess the effect of somatostatin analogs (SSAs) on mortality in relation to disease control of acromegaly after pituitary surgery. Design A retrospective study in two large tertiary referral centers in The Netherlands. Methods Overall, 319 patients with acromegaly in whom pituitary surgery was performed as primary therapy between January 1980 and July 2017 were included. Postoperative treatment with SSA was prescribed to 174 (55%) patients because of persistent or recurrent disease. Disease control at last visit was assessed by IGF1 standard deviation score (SDS). Adequate disease control was defined as IGF1 SDS ≤2. Univariate determinants of mortality and standardized mortality ratios (SMRs) were calculated for groups with and without SSA at any moment postoperatively and at last visit. Results In total, 27 deaths were observed. In univariate analysis, determinants of mortality were inadequate disease control (relative risk (RR): 3.41, P = 0.005), surgery by craniotomy (RR: 3.53, P = 0.013) and glucocorticoid substitution (RR: 2.11, P = 0.047). There was a strong trend toward increased mortality for patients who used SSA (RR: 2.01, P = 0.067) and/or dopamine agonists (RR: 2.54, P = 0.052) at last visit. The SMR of patients with adequate disease control who used SSA at any moment postoperatively (1.07, P = 0.785) and at last visit (1.19; P = 0.600) was not increased. Insufficiently controlled patients had a significantly raised SMR (3.92, P = 0.006). Conclusions Postoperative use of SSA is not associated with increased mortality in patients with acromegaly who attain adequate disease control. In contrast, inadequate disease control, primary surgery by craniotomy and glucocorticoid substitution are associated with increased mortality.
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http://dx.doi.org/10.1530/EJE-18-0166DOI Listing
January 2019

Primary aldosteronism is associated with decreased low-density and high-density lipoprotein particle concentrations and increased GlycA, a pro-inflammatory glycoprotein biomarker.

Clin Endocrinol (Oxf) 2019 01 20;90(1):79-87. Epub 2018 Nov 20.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Background: Primary aldosteronism (PA) may confer increased cardiovascular risk beyond effects on systemic blood pressure, but contributing mechanisms remain incompletely understood. We compared plasma (apo)lipoproteins and lipoprotein particle characteristics, GlycA, a pro-inflammatory glycoprotein biomarker of enhanced chronic inflammation, and plasma total branched-chain amino acids (BCAA), measured using nuclear magnetic resonance (NMR) spectroscopy, between patients with PA, control subjects without hypertension, subjects with untreated hypertension and subjects with treated hypertension.

Methods: Twenty PA patients were individually matched with 2819 control subjects without hypertension, 501 subjects with untreated hypertension and 878 subjects with treated hypertension participating in the PREVEND (Prevention of Renal and Vascular End-Stage Disease) cohort study with respect to age, sex, body mass index, smoking and statin use. The Vantera® Clinical Analyzer was used to determine NMR-based laboratory parameters.

Results: Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) B, apolipoprotein A-I (apoA-I), LDL particle and HDL particle concentrations were all decreased in PA subjects vs control subjects and subjects with untreated hypertension (P < 0.016). Triglycerides (TG) and triglyceride-rich lipoprotein (TRL) concentrations were lower in PA subjects vs subjects with (untreated) hypertension. GlycA was increased in PA vs the three comparator groups (P < 0.016). Total BCAA concentrations were unaltered in PA.

Conclusions: Primary aldosteronism is associated with lower concentrations of LDL and HDL particles and to some extent also with lower TG and TRL particle concentrations. PA is also characterized by increased GlycA levels, indicating enhanced low-grade chronic inflammation. Low HDL particle concentrations and increased GlycA could contribute to accelerated cardiovascular disease development in PA.
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http://dx.doi.org/10.1111/cen.13891DOI Listing
January 2019

Higher plasma GlycA, a novel pro-inflammatory glycoprotein biomarker, is associated with reduced life expectancy: The PREVEND study.

Clin Chim Acta 2019 Jan 23;488:7-12. Epub 2018 Oct 23.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.

Objective: Elevated circulating levels of pro-inflammatory biomarkers are associated with adverse health effects, but the extent to which enhanced low-grade inflammation influences remaining life expectancy (LE) is uncertain. GlycA is a novel pro-inflammatory marker. We determined effects of GlycA and high sensitivity C-reactive protein (hsCRP) on LE.

Methods: GlycA and hsCRP were determined in 5526 subjects. LE was compared in the upper quartile of both GlycA and hsCRP vs. the respective lower three quartiles combined, adjusted for LE of individuals in the Dutch general population of the same birth cohort and sex.

Results: Median follow up was 8.5 years [interquartile range 7.9-9.0], during which 348 (6.3%) subjects had deceased. LE at the end of follow up was lower in the highest vs. the lower three quartiles of GlycA (P < .001) and hsCRP (P < .001). Both men as well as women in the highest GlycA quartile had reduced LE vs. the lowest three quartiles combined (P < .001 and P = .02). For hsCRP, this was only observed in men (P < .001) but not in women (P = .67).

Conclusions: This population-based cohort study demonstrates that higher plasma levels of GlycA were associated with reduced LE in men and women. With regard to hsCRP this only applied to men.
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http://dx.doi.org/10.1016/j.cca.2018.10.029DOI Listing
January 2019

Clinical Applicability of Low Levels of Thyroglobulin Autoantibodies as Cutoff Point for Thyroglobulin Autoantibody Positivity.

Thyroid 2019 01 18;29(1):71-78. Epub 2018 Dec 18.

1 Department of Endocrinology and University of Groningen, Groningen, The Netherlands.

Background: Thyroglobulin (Tg) is an established tumor marker in differentiated thyroid carcinoma (DTC). However, Tg assays can be subject to interference by autoantibodies against Tg (TgAbs). No clinical consensus exists on the cutoff value of TgAb positivity and its relationship to Tg assay interference. The aims of this study were to investigate the most applicable cutoff value for TgAb positivity in clinical practice and to evaluate whether tumor characteristics differ between TgAb+ and TgAb- patients during ablation therapy using the manufacturer's cutoff (MCO) and institutional cutoff (ICO).

Methods: This single-center cohort study included 230 DTC patients diagnosed between January 2006 and December 2014. Serum Tg and TgAbs were measured with the Tg-IRMA (Thermo Fisher Scientific) and ARCHITECT Anti-Tg (Abbott Laboratories) assays. Patients were divided into TgAb- and TgAb+ based on the limit of detection (LoD; ≥0.07 IU/mL), functional sensitivity (FS; ≥0.31 IU/mL), MCO (≥4.11 IU/mL), and ICO (≥10 IU/mL).

Results: All patients were TgAb+ based on the LoD; one patient was negative on FS. Fifty-five (23.9%) and 34 (14.8%) patients had TgAbs above the MCO and ICO, respectively. Histology, presence of multifocality, tumor-node-metastasis, and American Thyroid Assocation risk stratification did not differ between TgAb- and TgAb+ patients using MCO and ICO during ablation.

Conclusions: This study supports the use of a higher cutoff value than that of the FS for TgAb positivity in clinical settings. The LoD and FS are too sensitive to discriminate TgAb positivity and negativity in DTC patients during ablation therapy. The presence of TgAbs during ablation is not related to tumor characteristics and risk profile. This implies that TgAb positivity should not be considered a separate risk factor.
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http://dx.doi.org/10.1089/thy.2018.0195DOI Listing
January 2019

Self-monitoring physical activity with a smartphone application in cancer patients: a randomized feasibility study (SMART-trial).

Support Care Cancer 2018 Nov 21;26(11):3915-3923. Epub 2018 May 21.

Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands.

Purpose: Evidence accumulates that an active lifestyle positively influences cancer treatment outcome. A "smartphone application" (app) such as "RunKeeper," to self-monitor physical activity (PA) might be helpful. This study aimed to examine whether using RunKeeper to increase self-reported PA is feasible in cancer patients and to evaluate patients' opinion about using RunKeeper in a 12-week program.

Methods: Adult patients (n = 32), diagnosed with cancer, were randomized between usual care (n = 16) or a 12-week intervention with instructions to self-monitor PA with RunKeeper (n = 16). Changes in PA were determined with the Physical Activity Scale for the Elderly (PASE) at baseline (T0), 6 weeks (T1), and 12 weeks (T2). Usability and patients' experiences were tested at T2 with the System Usability Scale (SUS) and a semi-structured interview.

Results: Patient mean age was 33.6 years. Between T0 and T1, an increase in PA of 51% (medium estimated effect size r = 0.40) was found in PASE sum score in the intervention group compared with usual care. In addition, total minutes of PA increased with 46% (r = 0.37). These effects decreased over time (T2). Sedentary time decreased with 19% between T0 and T1 and 27% between T0 and T2. Usability was rated "good" and most patients found RunKeeper use helpful to improve PA.

Conclusions: Self-monitoring PA with RunKeeper was safe and feasible in cancer patients. The RunKeeper use resulted in an increase in PA after 6 weeks. RunKeeper usability was rated good and can be used to study PA in cancer patients.

Trial Registration: NCT02391454.
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http://dx.doi.org/10.1007/s00520-018-4263-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6182373PMC
November 2018

Life expectancy is unaffected by thyroid function parameters in euthyroid subjects: The PREVEND cohort study.

Eur J Intern Med 2017 Dec 6;46:e36-e39. Epub 2017 Nov 6.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, The Netherlands. Electronic address:

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http://dx.doi.org/10.1016/j.ejim.2017.10.017DOI Listing
December 2017

Cholesterol delivery to the adrenal glands estimated by adrenal venous sampling: An in vivo model to determine the contribution of circulating lipoproteins to steroidogenesis in humans.

J Clin Lipidol 2017 May - Jun;11(3):733-738. Epub 2017 Apr 5.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Background: Cholesterol, required for adrenal steroid hormone synthesis, is at least in part derived from circulating lipoproteins. The contribution of high-density lipoproteins (HDL) and low-density lipoproteins (LDL) to adrenal steroidogenesis in humans is unclear.

Objective: The aim of the study was to determine the extent to which HDL and LDL are taken up by the adrenal glands using samples obtained during adrenal venous sampling (AVS).

Methods: AVS was successfully performed in 23 patients with primary aldosteronism. Samples were drawn from both adrenal veins and inferior vena cava (IVC). HDL cholesterol (HDL-C) and lipoprotein particle profiles were determined by nuclear magnetic resonance spectroscopy. Apolipoprotein (apo) A-I and apoB were assayed by immunoturbidimetry.

Results: Plasma HDL-C and HDL and LDL particle concentrations (HDL-P and LDL-P) were not lower in samples obtained from the adrenal veins compared with the IVC (HDL-C, P = .59; HDL-P, P = .06; LDL-P, P = .93). ApoB was lower in adrenal venous plasma than in IVC (P = .026; P < .05 for right adrenal vein). In 13 patients with an aldosterone producing adenoma (APA), apoB was also lower (P = .045) and LDL-P tended to be lower (P = .065) in the APA adrenal vein compared with the IVC. ApoA-I was not lower in adrenal venous plasma compared with the IVC, neither in the whole group (P = .20) nor in the APA subgroup (P = .075).

Conclusion: These in vivo observations suggest that circulating LDL may contribute to adrenal steroidogenesis in humans as inferred from adrenal venous-IVC apoB concentration differences. AVS is a feasible method to investigate the relationships between lipoproteins and steroidogenesis.
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http://dx.doi.org/10.1016/j.jacl.2017.03.018DOI Listing
December 2017

The clinical value of regular thyroid function tests during amiodarone treatment.

Eur J Endocrinol 2017 Jul 19;177(1):9-14. Epub 2017 Apr 19.

Department of Internal MedicineDivision of Endocrinology.

Objective: Amiodarone is used for the maintenance of sinus rhythm in patients with arrhythmias, but thyroid dysfunction (amiodarone-induced thyrotoxicosis (AIT) or amiodarone-induced hypothyroidism (AIH)) is a common adverse effect. As the onset of AIT and AIH may be unpredictable, the value of long-term regular monitoring of amiodarone treated patients for thyroid dysfunction is still uncertain.

Design: We retrospectively documented the frequency at which overt thyroid dysfunction was preceded by subclinical thyroid dysfunction.

Methods: We included 303 patients treated with amiodarone between 1984 and 2007. AIT was defined as a lowered TSH level with an elevated free thyroxine (FT4) and AIH was defined as an elevated TSH level with a decreased or subnormal FT4. Subclinical AIT was defined as a lowered TSH level with a normal FT4 and subclinical AIH as an elevated TSH level with a normal FT4.

Results: 200 men and 103 women, aged 62 ± 12.0 years, suffering from atrial (260) or ventricular (43) arrhythmias, were evaluated. During a median follow-up of 2.8 (1.0-25) years, 44 patients developed AIT and 33 AIH. In 42 (55%) patients who developed AIT/AIH, earlier thyroid function tests showed no subclinical AIT or subclinical AIH. In 35 (45%) patients, AIT/AIH was preceded by subclinical AIT or subclinical AIH (16/44 for AIT and 19/33 for AIH).

Conclusions: In a considerable proportion of patients who developed AIT/AIH, earlier thyroid function tests showed no subclinical AIT/AIH. Less than half of the patients with a subclinical event subsequently developed overt AIT/AIH. This study provides data to reconsider the yield of regular testing of thyroid function to predict overt thyroid dysfunction in amiodarone treated patients.
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http://dx.doi.org/10.1530/EJE-17-0018DOI Listing
July 2017

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

Clin Endocrinol (Oxf) 2017 Mar 28;86(3):419-424. Epub 2016 Sep 28.

Department of Endocrinology, University Medical Center Groningen, Groningen, The Netherlands.

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.
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http://dx.doi.org/10.1111/cen.13180DOI Listing
March 2017

Calculating the optimal surveillance for head and neck paraganglioma in SDHB-mutation carriers.

Fam Cancer 2017 01;16(1):123-130

Department of Endocrinology and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.

Germline mutations of the gene encoding succinate dehydrogenase subunit B (SDHB) predispose to head-and-neck-paraganglioma (HNPGL), sympathetic PGL, pheochromocytoma and renal cell carcinoma for which regular surveillance is required. SDHB-associated tumors harbor germline and somatic mutations, consistent with Knudson's two-hit hypothesis. To assess the penetrance and optimal surveillance for different manifestations of SDHB mutation carriers. This study included all SDHB mutation carriers who were followed at the Department of Endocrinology at the University Medical Center of Groningen. Kaplan-Meier curves were used to assess the penetrance. Poisson process was used to assess the optimal age to start surveillance and intervals. Ninety-one SDHB-mutation carriers (38 men and 53 women) were included. Twenty-seven mutation carriers (30 %) had manifestations, with an overall penetrance 35 % at the age of 60 years. We calculated that optimal surveillance for HNPGL could start from an age of 27 years with an interval of 3.2 years. This study underscores the relatively low penetrance of disease in SDHB mutation carriers. Use of the Poisson approach provides a more accurate estimation of the age to initiate surveillance and length of intervals for HNPGL. These results may give rise to reconsider the current guidelines regarding the screening of these mutation carriers.
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http://dx.doi.org/10.1007/s10689-016-9923-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5243881PMC
January 2017

89Zr-Bevacizumab PET Visualizes Disease Manifestations in Patients with von Hippel-Lindau Disease.

J Nucl Med 2016 08 12;57(8):1244-50. Epub 2016 May 12.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands

Unlabelled: Patients with von Hippel-Lindau disease (VHL) are at risk to develop multiple tumors. The growth of lesions is unpredictable, and regular surveillance is critical for early treatment to control local damage. Vascular endothelial growth factor A (VEGF-A) produced locally is supposed to play an important role in development of disease manifestations and is a target for antiangiogenic therapy with the monoclonal antibody bevacizumab. We aimed to assess whether VHL manifestations can be visualized with (89)Zr-bevacizumab PET and to explore whether (89)Zr-bevacizumab PET can differentiate progressive from nonprogressive lesions.

Methods: VHL patients with at least 1 measurable hemangioblastoma were eligible. (89)Zr-bevacizumab (37 MBq) was administered intravenously 4 d before the scan. Maximum standardized uptake values were calculated. PET scans were fused with routine MRI of the central nervous system and abdominal MRI or CT. Progressive lesions were defined as new lesions, lesions that became symptomatic, and lesions ≥ 10 mm that increased ≥ 10% and ≥ 4 mm on repeated anatomic imaging within 12 mo.

Results: Twenty-two patients were enrolled. At baseline, anatomic imaging showed 311 lesions. (89)Zr-bevacizumab PET visualized 59 VHL manifestations, 0-17 per patient. The median of maximum standardized uptake values was 8.5 (range, 1.3-35.8). The detection rate for lesions ≥ 10 mm was 30.8%. Seven additional hotspots without substrate on baseline anatomic imaging were found; 2 were also detected with anatomic imaging during follow-up. Nine of 25 progressive lesions were visible on PET and 27 of 175 nonprogressive lesions, corresponding to a positive predictive value of 25% and a negative predictive value of 90%. SUVmax was similar in progressive and nonprogressive lesions (median, 4.8; range, 0.9-8.9 vs. median, 6.7; range, 1.3-35.8, P = 0.14).

Conclusion: VHL manifestations can be visualized with (89)Zr-bevacizumab PET with a striking heterogeneity in tracer accumulation. (89)Zr-bevacizumab uptake does not predict progression within 12 mo. In one third of the lesions, the drug target VEGF is available and accessible. (89)Zr-bevacizumab PET might offer a tool to select VHL patients for anti-VEGF therapy.
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http://dx.doi.org/10.2967/jnumed.115.167643DOI Listing
August 2016

Potential value of EUS in pancreatic surveillance of VHL patients.

Eur J Endocrinol 2016 May 16;174(5):611-20. Epub 2016 Feb 16.

Department of EndocrinologyUniversity of Groningen, University Medical Center Groningen, Groningen, The Netherlands

Background: Patients with von Hippel-Lindau (VHL) disease are prone to develop pancreatic neuroendocrine tumors (pNETs). However, the best imaging technique for early detection of pNETs in VHL is currently unknown. In a head-to-head comparison, we evaluated endoscopic ultrasound (EUS) and (11)C-5-hydroxytryptophan positron emission tomography ((11)C-5-HTP PET) compared with conventional screening techniques for early detection of pancreatic solid lesions in VHL patients.

Methods: We conducted a cross-sectional, prospective study in 22 patients at a tertiary care university medical center. Patients with VHL mutation or with one VHL manifestation and a mutation carrier as first-degree family member, with recent screening by abdominal computed tomography (CT) or magnetic resonance imaging (MRI) and somatostatin receptor scintigraphy (SRS), were eligible. Patients underwent EUS by linear Pentax echoendoscope and Hitachi EUB-525, and (11)C-5-HTP PET. Patient-based and lesion-based positivity for pancreatic solid lesions were calculated for all imaging techniques with a composite reference standard.

Results: In 10 of the 22 patients, 20 pancreatic solid lesions were detected: 17 with EUS (P < 0.05 vs CT/MRI+ SRS), 3 with (11)C-5-HTP PET, 3 with SRS, 9 with CT/MRI, and 9 with CT/MRI + SRS. EUS evaluations showed solid lesions with a median size of 9.7 mm (range 2.9-55 mm) and most of them were homogeneous, hypoechoic, isoelastic, and hypervascular. Moreover, EUS detected multiple pancreatic cysts in 18 patients with a median of 4 cysts (range 1-30).

Conclusions: EUS is superior to CT/MRI + SRS for detecting pancreatic solid lesions in VHL disease.(11)C-5-HTP PET has no value as a screening method in this setting. EUS performs well in early detection of pNETs, but its role in VHL surveillance is unclear.
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http://dx.doi.org/10.1530/EJE-15-1012DOI Listing
May 2016

Hydrocortisone Dose Influences Pain, Depressive Symptoms and Perceived Health in Adrenal Insufficiency: A Randomized Controlled Trial.

Neuroendocrinology 2016 9;103(6):771-8. Epub 2015 Dec 9.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Background: There is a major lack of randomized controlled trials (RCTs) evaluating the effects of hydrocortisone (HC) substitution therapy in patients with secondary adrenal insufficiency. Therefore, we evaluated the effects of two different replacement doses of HC on health-related quality of life (HRQoL) in a RCT.

Methods: This RCT with a double-blind cross-over design was performed at the University Medical Center Groningen. Forty-seven patients (29 men, age 51 ± 14 years, range 19-73 years) with secondary adrenal insufficiency participated. Patients received both a lower and a higher dose of HC (0.2-0.3 and 0.4-0.6 mg/kg body weight/day) for 10 weeks in random order. HRQoL was assessed with a daily mood and symptom checklist (Patient Health Questionnaire-15 [PHQ-15], Generalized Anxiety Disorder-7 [GAD-7], Patient Health Questionnaire-9 [PHQ-9]) and with questionnaires assessing general well-being (RAND 36-Item Health Survey [RAND-36]), mood (Hospital Anxiety and Depression Scale [HADS]) and fatigue (Multidimensional Fatigue Inventory-20 [MFI-20]). ClinicalTrials.gov identifier: NCT01546922.

Results: Patients receiving the higher dose of HC reported significantly fewer symptoms of depression (p = 0.016 and p = 0.045 for HADS and PHQ-9, respectively), less general and mental fatigue (p = 0.004 and p = 0.003, respectively, both MFI-20), increased motivation (p = 0.021, MFI-20), better physical functioning (p = 0.041), better general health (p = 0.013) and more vitality (p = 0.025) (all RAND-36). In addition, while on the higher dose, fewer somatic symptoms (p = 0.022) and less pain (p < 0.001) (both PHQ-15) were experienced.

Conclusions: On the higher dose of HC, patients reported a better HRQoL on various domains as compared to the lower dose of HC. The fact that a higher dose of HC may improve patient well-being should be taken into consideration when individualizing the HC substitution dose.
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http://dx.doi.org/10.1159/000442985DOI Listing
May 2017

Bone Marrow Function After (131)I Therapy in Patients With Differentiated Thyroid Carcinoma.

J Clin Endocrinol Metab 2015 Oct 11;100(10):3911-7. Epub 2015 Aug 11.

Departments of Endocrinology (H.T.P., E.N.K.H., W.J.S., A.N.A.v.d.H.-S., T.P.L.), Nuclear Medicine and Molecular Imaging (A.H.B.), Surgical Oncology (J.T.M.P.), and Hematology (G.W.v.I.), University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands.

Objective: The primary objective was to evaluate the short- and long-term toxic effects of radioiodine ((131)I) therapy on bone marrow function in differentiated thyroid carcinoma (DTC) patients. The secondary objective was to define characteristics of patients at risk for impaired bone marrow function after (131)I treatment.

Patients And Methods: DTC patients treated with (131)I between 1989 and 2013 were included. We excluded patients with morbidities or treatments that could have influenced blood count parameters. Baseline platelets, leukocytes, and hemoglobin levels were compared with blood counts at 3 and 6 months and at 1 and 5 years after treatment. Logistic multivariate regression analyses were performed to determine patient characteristics associated with thrombocytopenia.

Results: We included 331 patients. Mean ± SD age was 47.5 ± 17.2 years, and 74.0% were female. Posttreatment platelets were significantly decreased at 6 months and 1 year, as compared with baseline. Leukocyte counts were also decreased at 3 and 6 months and at 1 year after treatment. No decreases in hemoglobin were found. Five years after treatment, platelet and leukocyte counts were comparable with baseline. Fourteen patients (4.2%) developed transient posttreatment thrombocytopenia. Risk factors for thrombocytopenia were older age, T4 tumor stage, male gender, and cumulative dose (131)I. After a multivariate regression analysis, the cumulative dose (131)I remained independently associated with thrombocytopenia.

Conclusion: Posttreatment platelets and leukocytes were transiently decreased compared with pretreatment values in a general DTC population. Cumulative (131)I dose was independently associated with thrombocytopenia. Platelets and leukocytes normalized to baseline levels 5 years after treatment, implying that in most patients the clinical effects of bone marrow toxicity are limited.
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http://dx.doi.org/10.1210/jc.2015-2124DOI Listing
October 2015

Recombinant TSH stimulated remnant ablation therapy in thyroid cancer: the success rate depends on the definition of ablation success--an observational study.

PLoS One 2015 20;10(3):e0120184. Epub 2015 Mar 20.

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.

Introduction: Patients with differentiated thyroid cancer (DTC) are treated with (near)-total thyroidectomy followed by remnant ablation. Optimal radioiodine-131 (131I) uptake is achieved by withholding thyroid hormone (THW), pretreatment with recombinant human Thyrotropin Stimulating Hormone (rhTSH) is an alternative. Six randomized trials have been published comparing THW and rhTSH, however comparison is difficult because an uniform definition of ablation success is lacking. Using a strict definition, we performed an observational study aiming to determine the efficacy of rhTSH as preparation for remnant ablation.

Patients And Methods: Adult DTC patients with, tumor stage T1b to T3, Nx, N0 and N1, M0 were included in a prospective multicenter observational study with a fully sequential design, using a stopping rule. All patients received remnant ablation with 131I using rhTSH. Ablation success was defined as no visible uptake in the original thyroid bed on a rhTSH stimulated 150 MBq 131I whole body scan (WBS) 9 months after remnant ablation, or no visible uptake in the original thyroid bed on a post therapeutic WBS when a second high dose was necessary.

Results: After interim analysis of the first 8 patients, the failure rate was estimated to be 69% (90% confidence interval (CI) 20-86%) and the inclusion of new patients had to be stopped. Final analysis resulted in an ablation success in 11 out of 17 patients (65%, 95% CI 38-86%).

Conclusion: According to this study, the efficacy of rhTSH in the preparation of 131I ablation therapy is inferior, when using a strict definition of ablation success. The current lack of agreement as to the definition of successful remnant ablation, makes comparison between different ablation strategies difficult. Our results point to the need for an international consensus on the definition of ablation success, not only in routine patient's care but also for scientific reasons.

Trial Registration: Dutch Trial Registration NTR2395.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120184PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367989PMC
March 2016

Brain abnormalities on MRI in non-functioning pituitary adenoma patients treated with or without postoperative radiotherapy.

Radiother Oncol 2015 Feb 14;114(2):239-44. Epub 2015 Jan 14.

Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, The Netherlands.

Background And Purpose: To assess and compare brain abnormalities on Magnetic Resonance Imaging (MRI) in non-functioning pituitary macro-adenoma (NFA) patients treated with or without postoperative radiotherapy (RT).

Material And Methods: In 86 NFA patients, treated between 1987 and 2008 at the University Medical Center Groningen, white-matter lesions (WMLs), cerebral atrophy, brain infarctions and abnormalities of the temporal lobes and hippocampi were assessed on pre- and post-treatment MRI scans in patients treated with (n=47) or without RT.

Results: The median MRI follow-up time for RT patients was 10 (range 1-22) years and 5 (range 1-21) years in patients treated without RT. In RT patients the cumulative incidence of WMLs was significantly lower compared to patients treated without RT (log-rank test RR 0.49, 95% CI 0.25-0.97, p=.042). The cumulative incidences of cerebral atrophy, brain infarctions, abnormalities of the temporal lobes and hippocampi, and the severity of WMLs and cerebral atrophy ratings were not significantly different between the two treatment groups.

Conclusions: Brain abnormalities on MRI are not observed more frequently in NFA patients treated with RT compared to patients treated with surgery-alone. Furthermore, RT was not associated with an increased severity of WMLs and cerebral atrophy ratings in this cohort of NFA patients.
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http://dx.doi.org/10.1016/j.radonc.2015.01.003DOI Listing
February 2015

CXCR4 and CXCL12 Expression in Rectal Tumors of Stage IV Patients Before and After Local Radiotherapy and Systemic Neoadjuvant Treatment.

Curr Pharm Des 2015 ;21(17):2276-83

Department of Medical Oncology, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.

Metastatic rectal cancer patients could benefit from novel therapeutic approaches. The signaling network formed by chemokines and their receptors can promote metastasis and resistance to current anticancer treatments. This study assessed the expression of chemokine receptor 4 (CXCR4) and its ligand CXCL12 immuhistochemically in stage IV rectal tumors. Paraffin-embedded primary tumor collected before and after local radiotherapy and systemic treatment with bevacizumab, oxaliplatin and capecitabine was analyzed. Receptor and ligand expression was assessed in the cytoplasm and nucleus of tumor, stromal and normal rectal crypt cells. Baseline expression of CXCR4 and CXCL12 was correlated with patients' pathologic response to treatment. At diagnosis (n=46), 89% of the rectal tumors expressed cytoplasmic CXCR4 and 81% CXCL12. Nuclear CXCR4 expression in tumor cells was present in 30% and nuclear CXCL12 expression in 35% of the tumors. After radiochemotherapy and administration of bevacizumab, nuclear CXCL12 expression was observed in 79% of residual tumors, as compared to 31% of the paired tumor samples expressing nuclear CXCL12 before treatment (P=0.001). There were no differences in CXCR4 or CXCL12 expression at baseline between the patients who had (n=9) and did not have (n=30) a pathologic complete response. Our results show that CXCR4 and CXCL12 are extensively expressed in primary rectal tumors of patients presenting with metastatic disease, while radiochemotherapy and bevacizumab further upregulate CXCL12 expression. These data indicate the importance of the CXCR4/CXCL12 axis in rectal tumor biology, and may suggest the CXCR4/CXCL12 receptor-ligand pair as a potential therapeutic target in metastatic rectal cancer.
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http://dx.doi.org/10.2174/1381612821666150105155615DOI Listing
May 2016

EUS is superior for detection of pancreatic lesions compared with standard imaging in patients with multiple endocrine neoplasia type 1.

Gastrointest Endosc 2015 Jan;81(1):159-167.e2

Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Background: In multiple endocrine neoplasia type 1 (MEN1), pancreatic neuroendocrine tumors (pNETs) are the leading MEN1-related cause of death.

Objective: To evaluate EUS and (11)C-5-hydroxytryptophan positron emission tomography ((11)C-5-HTP PET), compared with the recommended screening techniques in MEN1 patients for early detection of pNETs.

Design: Cross-sectional study.

Setting: Tertiary-care university medical center.

Patients: This study involved 41 patients with a proven MEN1 mutation or with one MEN1 manifestation and a mutation carrier as a first-degree family member, with recent screening by abdominal CT or magnetic resonance imaging (MRI) and somatostatin receptor scintigraphy (SRS).

Interventions: EUS by using a linear Pentax echoendoscope and Hitachi EUB-525 and (11)C-5-HTP PET.

Main Outcome Measurements: Patient-based and lesion-based positivity for pNET was calculated for all imaging techniques. The McNemar test was used to compare the yield of the 4 imaging techniques.

Results: In 35 of 41 patients, 107 pancreatic lesions were detected in total. EUS detected 101 pancreatic lesions in 34 patients, (11)C-5-HTP PET detected 35 lesions in 19 patients, and CT/MRI + SRS detected 32 lesions in 18 patients (P < .001). (11)C-5-HTP PET performed similarly to CT/MRI + SRS and better compared with SRS only (13 lesions in 12 patients), both at a patient-based and lesion-based level (P < .05).

Limitations: Single-center study.

Conclusion: EUS is superior to CT/MRI + SRS for pancreatic lesion detection in patients with MEN1. In this setting, (11)C-5-HTP PET is not useful. We recommend EUS as the first-choice pancreas imaging technique in patients with MEN1. (

Clinical Trial Registration Number: NTR1668.).
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http://dx.doi.org/10.1016/j.gie.2014.09.037DOI Listing
January 2015

89Zr-bevacizumab PET visualizes heterogeneous tracer accumulation in tumor lesions of renal cell carcinoma patients and differential effects of antiangiogenic treatment.

J Nucl Med 2015 Jan 4;56(1):63-9. Epub 2014 Dec 4.

Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Unlabelled: No validated predictive biomarkers for antiangiogenic treatment of metastatic renal cell carcinoma (mRCC) exist. Tumor vascular endothelial growth factor A (VEGF-A) level may be useful. We determined tumor uptake of (89)Zr-bevacizumab, a VEGF-A-binding PET tracer, in mRCC patients before and during antiangiogenic treatment in a pilot study.

Methods: Patients underwent (89)Zr-bevacizumab PET scans at baseline and 2 and 6 wk after initiating either bevacizumab (10 mg/kg every 2 wk) with interferon-α (3-9 million IU 3 times/wk) (n = 11) or sunitinib (50 mg daily, 4 of every 6 wk) (n = 11). Standardized uptake values were compared with plasma VEGF-A and time to disease progression.

Results: (89)Zr-bevacizumab PET scans visualized 125 evaluable tumor lesions in 22 patients, with a median SUV(max) (maximum standardized uptake value) of 6.9 (range, 2.3-46.9). Bevacizumab/interferon-α induced a mean change in tumor SUV(max) of -47.0% (range, -84.7 to +20.0%; P < 0.0001) at 2 wk and an additional -9.7% (range, -44.8 to +38.9%; P = 0.015) at 6 wk. In the sunitinib group, the mean change in tumor SUV(max) was -14.3% at 2 wk (range, -80.4 to +269.9; P = 0.006), but at 6 wk the mean change in tumor SUV(max) was +72.6% (range, -46.4 to +236%; P < 0.0001) above baseline. SUV(max) was not related to plasma VEGF-A at all scan moments. A baseline mean tumor SUV(max) greater than 10.0 in the 3 most intense lesions corresponded with longer time to disease progression (89.7 vs. 23.0 wk; hazard ratio, 0.22; 95% confidence interval, 0.05-1.00).

Conclusion: Tumor uptake of (89)Zr-bevacizumab is high in mRCC, with remarkable interpatient and intrapatient heterogeneity. Bevacizumab/interferon-α strongly decreases tumor uptake whereas sunitinib results in a modest reduction with an overshoot after 2 drug-free weeks. High baseline tumor SUV(max) was associated with longer time to progression.
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http://dx.doi.org/10.2967/jnumed.114.144840DOI Listing
January 2015

Fewer cancer reoperations for medullary thyroid cancer after initial surgery according to ATA guidelines.

Ann Surg Oncol 2015 Apr 15;22(4):1207-13. Epub 2014 Oct 15.

Department of Endocrinology, University Medical Center Groningen, Groningen, The Netherlands.

Background: Surgery is still the only curative treatment for medullary thyroid cancer (MTC). We evaluated clinical outcome in patients with locoregional MTC with regard to adequacy of treatment following ATA guidelines and number of sessions to first intended curative surgery in different hospitals.

Methods: We reviewed all records of MTC patients (n = 184) treated between 1980 and 2010 in two tertiary referral centers in the Netherlands. Symptomatic MTC (palpable tumor or suspicious lymphadenopathy) patients without distant metastasis were included (n = 86). Patients were compared with regard to adequacy of surgery according to ATA recommendations, tumor characteristics, number of local cancer reoperations, biochemical cure, clinical disease-free survival (DFS), overall survival (OS), and complications.

Results: Adherence to ATA guidelines resulted in fewer cancer-related reoperations (0.24 vs. 0.60; P = 0.027) and more biochemical cure (40.9 vs. 20 %; P = 0.038). Surgery according to ATA-guidelines on patients treated in referral centers was significantly more often adequate (59.2 vs. 26.7 %; P = 0.026). Tumor size and LN+ were the most important predictors for clinical recurrence [relative risk (RR) 4.1 (size > 40 mm) 4.1 (LN+) and death (RR 4.2 (size > 40 mm) 8.1 (LN+)].

Conclusions: ATA-compliant surgery resulted in fewer local reoperations and more biochemical cure. Patients in referral centers more often underwent adequate surgery according to ATA-guidelines. Size and LN+ were the most important predictors for DFS and OS.
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http://dx.doi.org/10.1245/s10434-014-4115-6DOI Listing
April 2015

Everolimus Reduces (89)Zr-Bevacizumab Tumor Uptake in Patients with Neuroendocrine Tumors.

J Nucl Med 2014 Jul 1;55(7):1087-92. Epub 2014 May 1.

Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands

Unlabelled: Everolimus increases progression-free survival in patients with advanced neuroendocrine tumors (NETs). Currently, no biomarkers are available for early selection of patients who will benefit from everolimus. Everolimus can reduce vascular endothelial growth factor A (VEGF-A) production by tumor cells. Therefore, we aimed to investigate the effect of everolimus on tumor uptake of the radioactive-labeled VEGF-A antibody bevacizumab with PET in NET patients.

Methods: Patients with advanced progressive well-differentiated NETs underwent (89)Zr-bevacizumab PET scans before and at 2 and 12 wk during everolimus treatment. (89)Zr-bevacizumab uptake was quantified by the maximum standardized uptake value (SUVmax). Tumor response and the percentage change in the sum of target lesion diameters were determined according to Response Evaluation Criteria in Solid Tumors 1.1 on CT (3 monthly).

Results: In 4 of the 14 patients entered, no tumor lesions were visualized with (89)Zr-bevacizumab PET. In the remaining patients, 19% of tumor lesions 1 cm or greater known by CT were visualized. Tumor SUVmax decreased during everolimus treatment, with a median of -7% at 2 wk (P = 0.09) and a median of -35% at 12 wk (P < 0.001). The difference in SUVmax at 2 and 12 wk with respect to SUVmax at baseline correlated with percentage change on CT at 6 mo (r(2) = 0.51, P < 0.05, and r(2) = 0.61, P < 0.01, respectively).

Conclusion: This study demonstrates variable (89)Zr-bevacizumab PET tumor uptake in NET patients. (89)Zr-bevacizumab tumor uptake diminished during everolimus treatment. Serial (89)Zr-bevacizumab PET might be useful as an early predictive biomarker of anti-VEGF-directed treatment in NET patients.
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http://dx.doi.org/10.2967/jnumed.113.129056DOI Listing
July 2014

Similar adverse pregnancy outcome in native and nonnative dutch women with pregestational type 2 diabetes: a multicentre retrospective study.

ISRN Obstet Gynecol 2013 30;2013:361435. Epub 2013 Oct 30.

Department of Endocrinology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands ; Department of Obstetrics and Gynaecology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.

Objective. To assess the incidence of adverse pregnancy outcome in native and nonnative Dutch women with pregestational type 2 diabetes (T2D) in a multicenter study in The Netherlands. Methods. Maternal characteristics and pregnancy outcome were retrospectively reviewed and the influence of ethnicity on outcome was evaluated using independent t-test, Mann-Whitney U-test, and chi-square test. Results. 272 pregnant women (80 native and 192 non-native Dutch) with pregestational T2D were included. Overall outcome was unfavourable, with a perinatal mortality of 4.8%, major congenital malformations of 6.3%, preeclampsia of 11%, preterm birth of 19%, birth weight >90th percentile of 32%, and a Caesarean section rate of 42%. In nonnative Dutch women, the glycemic control was slightly poorer and the gestational age at booking somewhat later as compared to native Dutch women. However, there were no differences in incidence of preeclampsia/HELLP, preterm birth, perinatal mortality, macrosomia, and congenital malformations between those two groups. Conclusions. A high incidence of adverse pregnancy outcomes was found in women with pregestational T2D, although the outcome was comparable between native and non-native Dutch women. This suggests that easy access to and adequate participation in the local health care systems contribute to these comparable outcomes, offsetting potential disadvantages in the non-native group.
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http://dx.doi.org/10.1155/2013/361435DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3833010PMC
December 2013

Calculating optimal surveillance for detection of von Hippel-Lindau-related manifestations.

Endocr Relat Cancer 2014 Feb 20;21(1):63-71. Epub 2013 Dec 20.

Departments of Medical Oncology Endocrinology, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands Department of Internal Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.

von Hippel-Lindau (VHL) mutation carriers develop benign and malignant tumors, requiring regular surveillance. The aim of this study was to calculate the optimal organ-specific age to initiate surveillance and optimal intervals to detect initial and subsequent VHL-related manifestations. In this study, we compare these results with the current VHL surveillance guidelines. We collected data from 82 VHL mutation carriers in the Dutch VHL surveillance program. The cumulative proportion of carriers diagnosed with a first VHL-related manifestation was estimated by the Kaplan-Meier method. The Poisson distribution model was used to calculate average time to detection of the first VHL-related manifestation and subsequent manifestations. We used this to calculate the optimal organ-specific age to initiate surveillance and the surveillance interval that results in a detection probability of 5%. The calculated organ-specific ages to initiate surveillance were 0 years (birth) for adrenal glands, 7 years for the retina, 14 years for the cerebellum, 15 years for the spinal cord, 16 years for pancreas, and 18 years for the kidneys. The calculated surveillance intervals were 4 years for the adrenal glands, biennially for the retina and pancreas, and annually for the cerebellum, spinal cord, and kidneys. Compared with current VHL guidelines, the calculated starting age of surveillance was 6 years later for the retina and 5 years earlier for adrenal glands. The surveillance intervals were two times longer for the retina and four times longer for the adrenal glands. To attain a 5% detection probability rate per organ, our mathematical model indicates that several modifications of current VHL surveillance guidelines should be considered.
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http://dx.doi.org/10.1530/ERC-13-0308DOI Listing
February 2014

Incidence, causative mechanisms, and anatomic localization of stroke in pituitary adenoma patients treated with postoperative radiation therapy versus surgery alone.

Int J Radiat Oncol Biol Phys 2013 Sep;87(1):53-9

Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Purpose: To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone.

Methods And Materials: A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log-rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population.

Results: Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049).

Conclusions: In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk factor was pre-existent coronary or peripheral artery disease.
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http://dx.doi.org/10.1016/j.ijrobp.2013.05.006DOI Listing
September 2013

18-fluorodeoxyglucose positron emission tomography in the early diagnostic workup of differentiated thyroid cancer patients with a negative post-therapeutic iodine scan and detectable thyroglobulin.

Thyroid 2013 Aug 31;23(8):1003-9. Epub 2013 Jul 31.

Department of Endocrinology, Groningen University Medical Centre, Groningen, The Netherlands.

Background: Surgery and high-dose radioactive iodine ((131)I) treatment are the cornerstones in the treatment of differentiated thyroid cancer. Patients without (131)I uptake on the post-therapeutic whole body scan (WBS), but with detectable thyroglobulin (Tg) during thyroxine withdrawal (Tg-off), are evaluated with an 18-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) for tumor localization within three months. The yield of (18)F-FDG-PET imaging and clinical usefulness of a Tg-off cutoff value to predict a positive scan were assessed.

Methods: From 2002 to 2011, 52 patients with a negative WBS and concurrent detectable Tg-off were evaluated. Thirty-five PET scans were performed during initial treatment, 17 after recurrent disease. Thirty-two patients were on substitution therapy, 17 were evaluated with endogenous thyrotropin elevation, and 3 after recombinant human thyrotropin stimulation. To determine the Tg-off cutoff value, a receiver operating characteristic curve was used.

Results: Nine (17%) (18)F-FDG-PET scans were true positive, 3 (6%) false positive, 36 (69%) true negative, and 4 (8%) false negative (sensitivity 69%, specificity 92%). In 13%, a true-positive scan resulted in a change in the clinical management. The area under the receiver operating characteristic curve is 0.82 [CI 0.64-0.99] (p<0.01), and the Tg-off cutoff value is 38.00 ng/mL (sensitivity 67%, specificity 95%). Ninety percent of (18)F-FDG-PET true-positive patients had a Tg-off >2.00 ng/mL.

Conclusions: An (18)F-FDG-PET within three months after a negative WBS with detectable Tg-off showed additional tumor localization in 17% of the patients, leading to a change in clinical management in 13%. A clinically useful Tg-off cutoff value was not found, but 90% of positive (18)F-FDG-PET scans occurred in patients with a Tg-off >2.00 ng/mL.
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http://dx.doi.org/10.1089/thy.2012.0498DOI Listing
August 2013

Unilateral and bilateral adrenalectomy for pheochromocytoma requires adjustment of urinary and plasma metanephrine reference ranges.

J Clin Endocrinol Metab 2013 Mar 30;98(3):1076-83. Epub 2013 Jan 30.

Department of Endocrinology and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB Groningen, The Netherlands.

Context: Follow-up after adrenalectomy for pheochromocytoma is recommended because of a recurrence risk. During follow-up, plasma and/or urinary metanephrine (MN) and normetanephrine (NMN) are interpreted using reference ranges obtained in healthy subjects.

Objective: Because adrenalectomy may decrease epinephrine production, we compared MN and NMN concentrations in patients after adrenalectomy to concentrations in a healthy reference population.

Design: A single-center cohort study was performed in pheochromocytoma patients after adrenalectomy between 1980 and 2011.

Subjects: Seventy patients after unilateral and 24 after bilateral adrenalectomy were included.

Main Outcome Measures: Plasma-free and urinary-deconjugated MN and NMN determined at 3 to 6 months and annually until 5 years after adrenalectomy were compared with concentrations in a reference population. Data are presented in median (interquartile range).

Results: Urinary and plasma MN concentrations 3 to 6 months after unilateral adrenalectomy were lower compared with the reference population (39 [31-53] μmol/mol creatinine and 0.14 [0.09-0.18] nmol/L vs 61 [49-74] μmol/mol creatinine and 0.18 [0.13-0.23] nmol/L, respectively, both P < .05). Urinary MN after bilateral adrenalectomy was reduced even further (7 [1-22] μmol/mol creatinine; P < .05). Urinary and plasma NMN were higher after unilateral adrenalectomy (151 [117-189] μmol/mol creatinine and 0.78 [0.59-1.00] nmol/L vs 114 [98-176] μmol/mol creatinine and 0.53 [0.41-0.70] nmol/L; both P < .05). Urinary NMN after bilateral adrenalectomy was higher (177 [106-238] μmol/mol creatinine; P < .05). Changes in urinary and plasma MNs persisted during follow-up.

Conclusion: Concentrations of MN are decreased, whereas NMN concentrations are increased after unilateral and bilateral adrenalectomy. Adjusted reference values for MN and NMN are needed in the postsurgical follow-up of pheochromocytoma patients.
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http://dx.doi.org/10.1210/jc.2012-3418DOI Listing
March 2013

Statin and fibrate combination does not additionally lower plasma cholesteryl ester transfer in type 2 diabetes mellitus.

Clin Lab 2012 ;58(11-12):1231-9

Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen 9700 RB, The Netherlands.

Background: Plasma cholesteryl ester transfer (CET) from high density lipoproteins (HDL) to very low and low density lipoproteins (VLDL+LDL) may predict (subclinical) atherosclerosis. We tested the extent to which plasma CET and cholesterol esterification (EST) are decreased by statin and fibrate combination therapy compared to statin and fibrate administration alone in type 2 diabetic patients.

Methods: Plasma CET and EST were measured by isotope assays in 14 type 2 diabetic patients, in whom a randomized placebo-controlled crossover study was carried out (8 weeks treatment with simvastatin (40 mg daily), bezafibrate (400 mg daily) and their combination). Plasma CET and EST from diabetic patients were compared with 42 non-diabetic control subjects with similar triglyceride levels.

Results: Plasma CET and EST were elevated in diabetic patients at baseline compared to control subjects (p < 0.01), and were correlated positively with non-HDL cholesterol and triglycerides in non-diabetic subjects and in diabetic patients at baseline (p < 0.01). Decreases in CET during combined treatment (p < 0.05) were not greater than the changes during simvastatin and bezafibrate monotherapy (p > 0.20). EST only decreased during bezafibrate therapy (p < 0.05). Changes in CET during treatment were correlated positively with changes in non-HDL cholesterol (p < 0.05) and triglycerides (p < 0.001). Changes in HDL cholesterol were related inversely to changes in CET (p < 0.05).

Conclusions: Diabetes-associated plasma CET elevations are ameliorated by statin and fibrate monotherapy, but combined lipid lowering drug treatment does not additively lower CET. CET lowering likely contributes to HDL cholesterol changes during statin and fibrate administration.
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February 2013