Publications by authors named "Johannes M Bonfrer"

Objective: To present an update of the European Group on Tumor Markers guidelines for serum markers in epithelial ovarian cancer.

Methods: Systematic literature survey from 2008 to 2013. The articles were evaluated by level of evidence and strength of recommendation.

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A major application of tumor biomarkers is in serial monitoring of cancer patients, but there are no published guidelines on how to evaluate biomarkers for this purpose. The European Group on Tumor Markers has convened a multidisciplinary panel of scientists to develop guidance on the design of such monitoring trials. The panel proposes a 4-phase model for biomarker-monitoring trials analogous to that in use for the investigation of new drugs.

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Background: Chromogranin A (CgA) is the most important tumour marker for well-differentiated neuroendocrine tumours (NET) and neuron specific enolase (NSE) for poorly differentiated neuroendocrine carcinoma (NEC). This study investigated whether the markers progastrin-releasing peptide (proGRP) and cytokeratin fragments (CKfr) CK8, CK18 and CK19 (MonoTotal) can be of additional value to the histological classification and help predict survival in these patients.

Methods: CgA, NSE, proGRP and CKfr were measured in 242 patients with grade 1 NET (G1NET), 38 with grade 2 NET (G2NET), 42 with large cell NEC (LCNEC), 251 with small cell NEC (SCNEC) and in 282 healthy persons.

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In the event of diffuse hepatic metastases, hepatic artery embolization (HAE) can be a successful treatment option in patients with well-differentiated neuroendocrine tumours (NET). However, embolization causes hypoxia which stimulates angiogenesis and therefore tumour growth. This study investigates angiogenesis activity following HAE by measuring vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) and C-terminal proendothelin-1 (proET-1) in blood.

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Background: The serum level of the S-100B protein is increasingly used as a tumor marker in melanoma patients. The aims of this study were to assess the clinical relevance of increased S-100B during follow up of high-risk melanoma patients and to determine the value of subsequent whole-body PET/CT and brain MRI.

Materials And Methods: A retrospective analysis was performed of all 46 melanoma patients with a normal history and physical examination who were found to have an elevated serum S-100B level (> or =0.

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Purpose: For the last decade chromogranin-A (CgA) has been a well-established marker for neuroendocrine tumor (NET), and N-terminal pro-brain natriuretic peptide (NT-proBNP) has been a useful marker for left ventricular dysfunction. This study examined the diagnostic value of CgA and NT-proBNP for carcinoid heart disease (CHD), and their prognostic value for overall survival in NET patients.

Patients And Methods: Serum samples were obtained and cardiac ultrasound studies performed in 102 NET patients.

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Objective: Elevation of S100B has been shown after various neurologic diseases with cognitive dysfunction. The aim of this study was to compare the serum level of S100B of patients with and without delirium and investigate the possible associations with different subtypes of delirium.

Methods: Acutely admitted medical patients aged 65 years or more were included from 2005 through 2008.

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In search for novel markers for breast cancer, we aimed to identify and validate novel serum protein profiles specific for breast cancer, and assess the influence of clinical (subjects age) and pre-analytical (sample storage duration) variables on the constructed classifiers. To this end, sera of breast cancer patients (n=152) and healthy controls (n=129), randomly divided into a training and test set, were analysed by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS). In the training set, 14 peak clusters were found to differ significantly in expression between cases and controls.

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Background: S100B protein and Neuron Specific Enolase (NSE) can increase due to brain cell damage and/or increased permeability of the blood-brain-barrier. Elevation of these proteins has been shown after various neurological diseases with cognitive dysfunction. Delirium is characterized by temporal cognitive deficits and is an important risk factor for dementia.

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Background: Issues have been raised concerning the robustness and validity of alleged serum markers discovered by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS). Pre-analytical variables have been shown to exert a profound effect on protein profiles, irrespective of true biological variation. However, little is known about the possible effects of sample storage duration on protein profiles.

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Objective: The aim of this study was to compare hormone levels between women who became postmenopausal after a prophylactic bilateral salpingo-oophorectomy, and women who became postmenopausal in a natural way.

Methods: In this cross-sectional study, we investigated estradiol, testosterone, SHBG, IGF-1 and IGFBP-3 levels in 35 surgically and 40 naturally postmenopausal women.

Results: Serum samples were drawn at a mean age of 45.

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Background: Increased insulin-like growth factor (IGF)-I and IGF-II concentrations are related to increased colorectal cancer risk. Isoflavones have been associated with reduced colorectal cancer risk, and may affect the IGF system because of their weak estrogenic activity. The aim of the study was to investigate the effect of isolated isoflavones on serum concentrations of IGF system components.

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Background: Urinary 5-HIAA excretion is a well-known marker in neuroendocrine tumors (NETs), but it has a low sensitivity and the 24-hour collection is inconvenient for patients. Chromogranin A (CgA) is a promising marker, but a thorough evaluation during follow-up is still lacking.

Methods: 39 patients with metastatic gastrointestinal NETs were monitored during treatment with the long-acting octreotide SandostatinLAR.

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Insulin-like growth factor-I (IGF-I) is an important growth factor associated with increased risk of premenopausal breast cancer. We conducted a randomized, placebo-controlled, double-blind, crossover trial to evaluate whether tomato-derived lycopene supplementation (30 mg/day for 2 mo) decreases serum levels of total IGF-I in premenopausal women with 1) a history of breast cancer (n=24) or 2) a high familial breast cancer risk (n=36). Also, IGF binding protein (IGFBP) increasing effects were evaluated.

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Background: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding proteins (IGFBPs).

Objective: The objective of our study was to investigate the effect of an 8-wk supplementation with tomato-derived lycopene (30 mg/d) on serum concentrations of total IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3.

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Background: Serum markers have been tested in patients with malignant effusions for their ability to differentiate malignant pleural mesothelioma from other causes. We have assessed three different serum markers and report our findings in a series of patients with different thoracic malignancies and a group of healthy controls.

Methods: A retrospective analysis of 179 patients and 50 healthy controls was performed.

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Purpose: Human papillomavirus (HPV) infections are suggested to be involved in the development of penile squamous cell carcinoma (SCC), but comprehensive studies to define the association are limited. Therefore, we performed molecular and serologic analyses for a broad spectrum of HPV types on a large series of 83 penile SCCs, and we compared serological findings to those of age-matched male controls (N = 83).

Methods: Penile SCCs were subjected to detection and typing assays for mucosal and cutaneous HPVs and to subsequent, type-specific viral load and viral gene expression assays.

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Currently, no suitable biomarker for the early detection or follow-up of renal cell carcinoma (RCC) is available. We aimed to validate previously reported potential serum biomarkers for RCC obtained with Surface Enhanced Laser Desorption Ionisation-Time of Flight Mass Spectrometry (SELDI-TOF MS) in our laboratory using distinct patient populations. Two sets of sera from RCC patients and healthy controls (HC) were gathered from different institutes and analysed according to published procedures.

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Epidemiological studies show that increased insulin-like growth factor (IGF)-I concentrations are related to increased colorectal cancer risk. A reduced colorectal cancer risk has been associated with isoflavones, which might affect the IGF-system because of their weak estrogenic activity. We conducted a randomized, placebo-controlled, double-blind crossover study to investigate the effect of an 8-wk isolated isoflavone supplementation (84 mg/d) on serum concentrations of total IGF-I, free IGF-I, total IGF-II, IGF binding protein (BP)-1, IGFBP-2, and IGFBP-3.

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Purpose: To determine whether a dose of 78 Gy improves outcome compared with a conventional dose of 68 Gy for prostate cancer patients treated with three-dimensional conformal radiotherapy.

Patients And Methods: Between June 1997 and February 2003, stage T1b-4 prostate cancer patients were enrolled onto a multicenter randomized trial comparing 68 Gy with 78 Gy. Patients were stratified by institution, age, (neo)adjuvant hormonal therapy (HT), and treatment group.

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Aim: To detect the new serum biomarkers for colorectal cancer (CRC) by serum protein profiling with surface-enhanced laser desorption ionisation--time of flight mass spectrometry (SELDI-TOF MS).

Methods: Two independent serum sample sets were analysed separately with the ProteinChip technology (set A: 40 CRC+49 healthy controls; set B: 37 CRC+31 healthy controls), using chips with a weak cation exchange moiety and buffer pH 5. Discriminative power of differentially expressed proteins was assessed with a classification tree algorithm.

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Leptomeningeal metastasis (LM) is a devastating complication that occurs in 5% of patients with breast cancer. Early diagnosis and initiation of treatment are essential to prevent neurological deterioration. However, early diagnosis of LM remains challenging because 25% of cerebrospinal fluid (CSF) samples produce false-negative results at first cytological examination.

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Background And Objectives: The clinical utility of the tumor marker serum S-100B has been described in determining prognosis, for early diagnosis of recurrence and for disease monitoring in melanoma patients. Sentinel node biopsy is increasingly used as staging procedure for patients with clinically localized melanoma. The aim of this study was to determine the value of serum S-100B in melanoma patients before and after sentinel lymph node biopsy.

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The value of normal S-100B levels to predict survival was evaluated in 145 patients with stage IV melanoma. Treatment consisted of temozolomide given alone or was followed by combined cytokine immunotherapy, given every three to four weeks, with an evaluation of response following two treatment-cycles. S-100B values were measured prior to and following each cycle of systemic therapy and regularly thereafter.

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