Ate G J van der Zee

University of Groningen, Groningen, Groningen, Netherlands

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Publications (124)662.61 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This study demonstrates that both the clinical sensitivity and specificity of the Cervista™ HPV HR test for high-risk human papillomavirus (HPV) detection were not inferior to those of the HC2 test. The intra- and inter-laboratory reproducibility of Cervista were respectively 92.0% (κ = 0.83) and 90.4% (κ = 0.80). The Cervista™ HPV HR test fulfills all the criteria of international guidelines of HPV test requirements for cervical primary screening purposes.
    Journal of clinical microbiology. 10/2014;
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    ABSTRACT: The aim of this study was to determine possible impact of routinely scheduled biopsies and more radical surgery for residual central disease in locally advanced cervical cancer after (chemo)radiation.
    International journal of gynecological cancer : official journal of the International Gynecological Cancer Society. 07/2014;
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    ABSTRACT: The diagnostic performance of the widely-used Cervista HPV HR test was compared to the Hybrid Capture 2 (HC2) test in a Dutch population-based cervical cancer screening program. In 900 scrapings of women with normal cytomorphology, specificity was 90% (95%CI: 87.84-91.87) for the Cervista HPV HR test and 96% (95%CI: 94.76-97.37) for the HC2 test with 93% agreement between both tests (κ = 0.5, p<0.001). The sensitivity for CIN2+ using 65 scrapings of women with histological-confirmed CIN2+ was 91% (95%CI: 80.97-96.51) for the Cervista HPV HR test and 92% (95%CI: 82.94-97.43) for the HC2 test with 95% agreement between both tests (κ = 0.7, p<0.001). Fifty-seven of 60 HC2 negative/Cervista positive cases tested HPV-negative with PCR-based HPV assays; of these cases 56% were defined as Cervista triple-positive with FOZ values in all 3 mixes higher than the second cut-off of 1.93 (as set by manufacturer). By setting this cut-off at 5.0, specificity improved significantly without affecting sensitivity. External validation of this new cut-off at 5.0 in triple-positive scrapings of women selected from the SHENCCASTII database revealed that 22/24 histological normal cases now tested HPV-negative in the Cervista HPV HR test, while CIN2+ lesions remained HPV-positive. The intra-laboratory reproducibility of the Cervista HPV HR test (n = 510) showed a concordance of 92% and 93% for cut-off 1.93 and 5.0 (κ = 0.83 and κ = 0.84, p<0.001) and inter-laboratory agreement of the Cervista HPV HR test was 90% and 93% for cut-off 1.93 and 5.0 (κ = 0.80 and κ = 0.85, p<0.001). In conclusion, the specificity of the Cervista HPV HR test could be improved significantly by increasing the second cut-off from 1.93 to 5.0, without affecting the sensitivity of the test in a population-based screening setting.
    PLoS ONE 01/2014; 9(7):e101930. · 3.53 Impact Factor
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    ABSTRACT: To elucidate the role of biological and clinical impact of aberrant promoter hypermethylation (PH) in ovarian cancer (OC). PH of PGP9.5, HIC1, AIM1, APC, PAK3, MGMT, KIF1A, CCNA1, ESR1, SSBP2, GSTP1, FKBP4 and VGF were assessed by quantitative methylation specific PCR (QMSP) in a training set. We selected two genes (VGF and PGP9.5) for further QMSP analysis in a larger independent validation (IV) set with available clinical data. Biologic relevance of VGF gene was also evaluated. PH frequency for PGP9.5 and VGF were 85% (316/372) and 43% (158/366) respectively in the IV set of samples while no PH was observed in controls. In 372 OC cases with available follow up, PGP9.5 and VGF PH were correlated with better patient survival [Hazard Ratios (HR) for overall survival (OS) were 0.59 (95% Confidence Intervals (CI) = 0.42-0.84, p = 0.004), and 0.73 (95%CI = 0.55-0.97, p = 0.028) respectively, and for disease specific survival (DSS) were 0.57 (95%CI 0.39-0.82, p = 0.003) and 0.72 (95%CI 0.54-0.96, p = 0.027). In multivariate analysis, VGF PH remained an independent prognostic factor for OS (HR 0.61, 95%CI 0.43-0.86, p<0.005) and DSS (HR 0.58, 95%CI 0.41-0.83, p<0.003). Furthermore, PGP9.5 PH was significantly correlated with lower grade, early stage tumors, and with absence of residual disease. Forced expression of VGF in OC cell lines inhibited cell growth. Our results indicate that VGF and PGP9.5 PH are potential biomarkers for ovarian carcinoma. Confirmatory cohorts with longitudinal follow-up are required in future studies to define the clinical impact of VGF and PGP9.5 PH before clinical application.
    PLoS ONE 10/2013; 8(9):e70878. · 3.53 Impact Factor
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    ABSTRACT: OBJECTIVE: to assess the prevalence of underlying bleeding disorders in women with heavy menstrual bleeding (HMB) with and without gynaecological abnormalities. STUDY DESIGN: we performed a single-centre prospective cohort study of 112 consecutive patients referred for heavy menstrual bleeding. Controls were 28 healthy volunteers who reported no HMB. Patients and controls had haemostatic testing in the 1(st) week after menstruation. Patients underwent gynaecologic evaluation. RESULTS: median age was 42.5 yrs (range 17-55) in patients and 40.0 yrs (range 25-55) in controls. Forty-six percent of patients had anaemia, median PBAC-score was 271. Seven percent of the controls with a subjectively normal menstruation had an anaemia. Twenty-six percent of patients had gynaecological abnormalities, considered to explain HMB. Overall, we found in 29% of the patients an underlying bleeding disorder, this was comparable for unexplained and explained HMB (31% vs 27%;p=0.75). We diagnosed 6 cases of VWD, 4 cases of FXI deficiency and one FVII deficiency. The only abnormalities found in controls were platelet aggregation defects (11% in controls vs 23% in patients). Patients had a significantly longer aPTT compared to controls (26.5 vs 25.0 sec; p=0.001), caused by lower median levels of FXI (100 vs 124 IU/dL; p<0.001). CONCLUSION: bleeding disorders play an equally important role in the aetiology of both unexplained and explained heavy menstrual bleeding. A novel finding is the occurrence of low, but not deficient levels of factor XI.
    American journal of obstetrics and gynecology 05/2013; · 3.28 Impact Factor
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    ABSTRACT: C13ORF18 is frequently hypermethylated in cervical cancer but not in normal cervix and might serve as a biomarker for the early detection of cervical cancer in scrapings. As hypermethylation is often observed for silenced tumor suppressor genes (TSGs), hypermethylated biomarker genes might exhibit tumor suppressive activities upon re-expression. Epigenetic drugs are successfully exploited to reverse TSG silencing, but act genome-wide. Artificial Transcription Factors (ATFs) provide a gene-specific approach for re-expression of silenced genes. Here, we investigated the potential tumor suppressive role of C13ORF18 in cervical cancer by ATF-induced re-expression. Five zinc finger proteins were engineered to bind the C13ORF18 promoter and fused to a strong transcriptional activator. C13ORF18 expression could be induced in cervical cell lines: ranging from >40-fold in positive (C13ORF18-unmethylated) cells to >110-fold in negative (C13ORF18-methylated) cells. Re-activation of C13ORF18 resulted in significant cell growth inhibition and/or induction of apoptosis. Co-treatment of cell lines with ATFs and epigenetic drugs further enhanced the ATF-induced effects. Interestingly, re-activation of C13ORF18 led to partial demethylation of the C13ORF18 promoter and decreased repressive histone methylation. These data demonstrate the potency of ATFs to re-express and potentially demethylate hypermethylated silenced genes. Concluding, we show that C13ORF18 has a TSG function in cervical cancer and may serve as a therapeutic anti-cancer target. As the amount of epimutations in cancer exceeds the number of gene mutations, ATFs provide promising tools to validate hypermethylated marker genes as therapeutic targets.
    Molecular oncology 03/2013; · 6.70 Impact Factor
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    ABSTRACT: Combined detection of CADM1 and MAL promoter methylation in cervical scrapes is a promising triage strategy for hrHPV-positive women. Here, CADM1 and MAL DNA methylation levels were analysed in cervical scrapes of hrHPV-positive women with no underlying high-grade disease, high-grade CIN and cervical cancer. CADM1 and MAL methylation levels in scrapes were firstly related to CIN-grade of the corresponding biopsy and secondly to CIN-grade stratified by the presence of 'normal' or 'abnormal' cytology as present in the accompanying scrape preceding the cervical biopsy. The scrapes included 167 women with ≤CIN1, 54 with CIN2/3 and 44 with carcinoma. In a separate series of hrHPV-positive scrapes of women with cervical intraepithelial neoplasia grade 2/3 (CIN2/3) (n=48), methylation levels were related to duration of preceding hrHPV infection (PHI; <5 and ≥5 years). Methylation levels were determined by quantitative methylation-specific PCR and normal cytology scrapes of hrHPV-positive women with histologically ≤CIN1 served as reference. CADM1 and MAL methylation levels increased proportional to severity of the underlying lesion, showing an increase of 5.3- and 6.2-fold in CIN2/3, respectively, and 143.5- and 454.9-fold in carcinomas, respectively, compared to the reference. Methylation levels were also elevated in CIN2/3 with a longer duration of PHI (i.e. 11.5- and 13.6-fold, respectively). Moreover, per histological category, methylation levels were higher in accompanying scrapes with abnormal cytology than in scrapes with normal cytology. Concluding, CADM1 and MAL promoter methylation levels in hrHPV-positive cervical scrapes are related to the degree and duration of underlying cervical disease and markedly increased in cervical cancer. © 2013 Wiley Periodicals, Inc.
    International Journal of Cancer 03/2013; · 6.20 Impact Factor
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    ABSTRACT: Macroporous reversed-phase (mRP) chromatography was successfully used to develop an accurate and precise method for total protein in serum. The limits of detection (0.83 μg, LOD) and quantification (2.51 μg, LOQ) for the mRP method are comparable with those of the widely used micro BCA protein assay. The mRP method can be used to determine the total protein concentration across a wide dynamic range by detecting chromatographic peaks at 215 nm and 280 nm. The method has the added advantage of desalting and denaturing proteins, leading to more complete digestion by trypsin and to better LC-MS-MS identification in shotgun proteomics experiments.
    Analytical and Bioanalytical Chemistry 02/2013; · 3.66 Impact Factor
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    ABSTRACT: Epigenetic modifications, such as aberrant DNA promoter methylation, are frequently observed in cervical cancer. Identification of hypermethylated regions allowing discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3), or worse, may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions was studied using genome-wide DNA methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methylated DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium. Hypermethylated differentially methylated regions (DMRs) were identified. Validation of nine selected DMRs using BSP and MSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was conducted exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples. Clinical validation of both markers in cervical scrapings from patients with an abnormal cervical smear confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion and that ROC analysis was discriminative. These markers represent the COL25A1 and KATNAL2 and their observed increased methylation upon progression could intimate the regulatory role in carcinogenesis. In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and are candidate biomarkers for early detection. "
    Epigenetics: official journal of the DNA Methylation Society 09/2012; 7(11). · 4.58 Impact Factor
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    ABSTRACT: PURPOSE: The mammalian target of rapamycin (mTOR) pathway is frequently activated in ovarian cancers. mTOR inhibitors, like everolimus, can reduce vascular endothelial growth factor-A (VEGF-A) production by cancer cells. We investigated whether early everolimus treatment effects could be monitored by positron emission tomography (PET) with 89Zr-bevacizumab. Experimental design: The effect of everolimus on VEGF-A secretion was determined in a panel of human ovarian cancer cell lines and in A2780luc+ ovarian cancer cells xenografted subcutaneously in BALB/c mice. Mice received daily 10 mg/kg everolimus intraperitoneally for 14 days. PET scans with the tracer 89Zr-labeled bevacizumab were performed before and after treatment. Ex vivo 89Zr-bevacizumab biodistribution and correlative tissue analyses were performed. Tumor VEGF-A levels were measured with ELISA and mean vascular density (MVD) was determined with immunohistochemistry. RESULTS: Everolimus treatment reduced VEGF-A levels in the supernatant of all cell lines. Everolimus lowered 89Zr-bevacizumab tumor uptake by 21.7 ± 4.0% (SUVmean 2.3 ± 0.2 versus 2.9 ± 0.2, P < 0.01). Ex vivo biodistribution also demonstrated lower tracer uptake in the tumors of treated compared to control animals (7.8 ± 0.8 %ID/g versus 14.0 ± 1.7 %ID/g, P < 0.01), while no differences were observed for other tissues. This coincided with lower VEGF-A protein levels in tumor lysates in treated versus untreated tumors (P = 0.04) and reduced MVD (P < 0.01). CONCLUSION: Tumor VEGF-A levels are decreased by everolimus. 89Zr-bevacizumab PET could be used to monitor tumor VEGF-A levels as an early biomarker of the antiangiogenic effect of mTOR inhibitor therapy.
    Clinical Cancer Research 09/2012; · 7.84 Impact Factor
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    ABSTRACT: Concurrent platinum-based chemoradiation significantly improved survival of advanced stage cervical patients over radiotherapy alone. However, the 5-year overall survival is still only 66%. Presently, no biomarkers are available to select those cervical cancer patients that might benefit from concurrent platinum-based chemoradiation therapy. DNA methylation is a well-established contributor to the regulation of gene transcription, predominantly causing transcriptional silencing. Differences in promoter hypermethylation patterns and subsequent silencing, could contribute to the variety of responses observed in clinical practice. Several clinical trials on various malignancies reported a better response when Decitabine was administered prior to or in combination with standard therapy. This sensitization is thought to be due to re-expression of tumor suppressor genes. However, not all patients might benefit from demethylating agents, since re-expression of oncogenes could render patients more resistant. In this review, we summarized the present state of art regarding hypermethylated genes and their affected signaling pathways that are associated with outcome after cisplatin treatment, radiotherapy or chemoradiation. Since only few studies were reported in cervical cancer, other malignancies were reviewed as well. From the data presented in this review, we conclude that, in order to select patients that benefit most optimally from demethylating strategies, a comprehensive screening of a large panel of methylation markers, associated with both good as well as poor clinical outcome have to be investigated. Since such panels are not available at this moment, global methylation screening approaches are required to profile such methylated genes. Such methylated gene profiles might be very useful to optimize personalized treatment planning not only in cervical cancer but also in other malignancies.
    Cellular oncology (Dordrecht). 08/2012; 35(4):231-41.
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    ABSTRACT: Radiotherapy is associated with short-term and long-term morbidity. This study compared toxicity rates among patients with endometrial carcinoma (EC) treated with adjuvant external beam radiation therapy (EBRT) on a small pelvic field (SmPF) in comparison with a standard pelvic field (StPF) or an extended field (EF). Patients with EC preoperatively diagnosed with high-grade histological disease (grade 3 endometrioid, papillary serous, clear cell, and mixed tumor type) or cervical involvement were treated with total abdominal hysterectomy, bilateral salpingo-oophorectomy, and lymphadenectomy in the University Medical Center Groningen between 1999 and 2008. Patients who received adjuvant EBRT were included in this study. External beam radiation therapy on SmPF (includes only the central pelvis and proximal vagina) was applied in case of negative lymph nodes after adequate lymphadenectomy (≥10 lymph nodes removed at the bilateral obturator and external iliac nodal stations). In case of positive pelvic lymph nodes or inadequate lymphadenectomy, EBRT on StPF was given. External beam radiation therapy on EF was applied in case of common iliac and/or para-aortic lymph node metastases. Retrospectively, using the Common Terminology Criteria for Adverse Events v3.0, acute toxicity was scored during radiotherapy, whereas late toxicity was scored, from 3 months onward after treatment. Toxicity could be evaluated in 75 patients treated with SmPF (n = 33), StPF (n = 28), and EF EBRT (n = 14). Most patients with late adverse events had also reported toxicity during radiotherapy (71%). The most common late adverse events were gastrointestinal tract related, more frequently present in the StPF group (60.7%) compared to SmPF (33.3%; P = 0.032). In particular, nausea and anorexia were more frequent in the StPF group (32.1%) compared to the SmPF group (3.0%; P = 0.004), as well as ileus (14.3% vs 0%, P = 0.039, respectively). Treatment with adjuvant EBRT on SmPF results in less gastrointestinal late adverse events compared to treatment with EBRT on StPF in patients with surgically staged EC.
    International Journal of Gynecological Cancer 07/2012; 22(7):1177-86. · 1.94 Impact Factor
  • Cellular oncology (Dordrecht). 06/2012; 35(3):229.
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    ABSTRACT: Insight into the expression of multiple vascular endothelial growth factor (VEGF) family members can support the implementation of anti-angiogenic therapy. This study aimed to assess VEGF family member expression in ovarian cancers and related omental metastases. Tissue microarrays encompassing 270 primary cancers and 112 paired metastases were immunostained for VEGF-A, VEGF-B, VEGF-C and VEGF-D. Staining intensities were categorized as absent, weak, moderate or strong. Expression was related to clinicopathological characteristics and survival. Immunohistochemical positivity (defined as moderate or strong expression) was observed for VEGF-A in 90%, VEGF-B in 4%, VEGF-C in 41% and VEGF-D in 55% of the primary ovarian cancers. VEGF-A expression correlated with VEGF-C and VEGF-D expression (P < 0.01). Simultaneous positivity for VEGF-A and VEGF-C or VEGF-D was observed in 38% and 54% of the cancers, respectively. Metastases showed positivity for VEGF-A in 78%, VEGF-B in 5%, VEGF-C in 26% and VEGF-D in 45% of cases. VEGF family member expression showed no independent prognostic significance in multivariate survival analysis. VEGF-A, VEGF-C and VEGF-D are widely and often simultaneously expressed in ovarian cancer, which may contribute to bevacizumab resistance. Measuring their expression could support a rational, individualized choice of anti-angiogenic therapy and might be of predictive value. Studies are warranted to determine whether combinatorial analysis of VEGF family member expression can be used to predict anti-angiogenic drug efficacy.
    Current pharmaceutical design 05/2012; 18(25):3784-92. · 4.41 Impact Factor
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    ABSTRACT: Despite efforts to improve chemotherapeutic efficacy in epithelial ovarian cancer, outcome for patients with advanced disease has remained unchanged since the introduction of standard carboplatin and paclitaxel. Interest has therefore shifted toward molecularly targeted therapies that interfere with important features of ovarian carcinogenesis, such as angiogenesis. Several angiogenesis inhibitors, targeting vascular endothelial growth factor (VEGF) ligands (bevacizumab, VEGF-Trap) or their receptors (VEGFR-targeted tyrosine kinase inhibitors) have been clinically evaluated. These agents demonstrated efficacy in phase II clinical trials. Results from phase III trials, in which bevacizumab was added to standard frontline chemotherapy, show a modest effect. Although the initial expectations for angiogenesis inhibitors have been tempered, further research is warranted to define their precise place in the treatment of ovarian cancer. This review summarizes the performed and ongoing studies with regard to angiogenesis inhibitors in ovarian cancer, and the available data on biomarkers for response prediction. Preclinical studies evaluating alternative angiogenesis inhibitors will also be discussed.
    Critical reviews in oncology/hematology 04/2012; 84(2):224-42. · 5.27 Impact Factor
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    ABSTRACT: In cervical cancer, the p53 and retinoblastoma (pRb) tumor suppressor pathways are disrupted by the human papilloma virus (HPV) E6 and E7 oncoproteins, because E6 targets p53 and E7 targets pRb for rapid proteasome-mediated degradation. We have investigated whether E6 suppression with small interfering RNA (siRNA) restores p53 functionality and sensitizes the HPV16-positive cervical cancer cell line SiHa to apoptosis by cisplatin, irradiation, recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL), or agonistic anti-Fas antibody. E6 siRNA resulted in decreased E6 mRNA levels and enhanced p53 and p21 expression, demonstrating the restoration of p53 functionality in SiHa cells, without inducing high levels of apoptosis (<10%). Cell surface expression of the proapoptotic death receptors (DRs) DR4, DR5, and Fas was not affected by E6 suppression. E6 suppression conferred susceptibility to cisplatin-induced apoptosis but not to irradiation-, rhTRAIL-, or anti-Fas antibody-induced apoptosis. Combining cisplatin with rhTRAIL or anti-Fas antibody induced even higher apoptosis levels in E6-suppressed cells. At the molecular level, cisplatin treatment resulted in elevated p53 levels, enhanced caspase-3 activation, and reduced p21 levels in E6-suppressed cells. Cisplatin in combination with death receptor ligands enhanced caspase-8 and caspase-3 activation and reduced X-linked inhibitor-of-apoptosis protein (XIAP) levels in these cells. We showed using siRNA that the enhanced apoptosis in E6-supressed cells was related to reduced XIAP levels and not due to reduced p21 levels. In conclusion, targeting E6 or XIAP in combination with cisplatin can efficiently potentiate rhTRAIL-induced apoptosis in HPV-positive cervical cancer cells.
    Molecular pharmacology 02/2012; 81(5):701-9. · 4.53 Impact Factor
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    ABSTRACT: Treatment of advanced-stage cervical cancers with (chemo)radiation causes cytotoxicity through induction of high levels of DNA damage. Tumour cells respond to DNA damage by activation of the 'DNA damage response' (DDR), which induces DNA repair and may counteract chemoradiation efficacy. Here, we investigated DDR components as potential therapeutic targets and verified the predictive and prognostic value of DDR activation in patients with cervical cancer treated with (chemo)radiation. In a panel of cervical cancer cell lines, inactivation of ataxia telangiectasia mutated (ATM) or its substrate p53-binding protein-1 (53BP1) clearly gave rise to cell cycle defects in response to irradiation. Concordantly, clonogenic survival analysis revealed that ATM inhibition, but not 53BP1 depletion, strongly radiosensitised cervical cancer cells. In contrast, ATM inhibition did not radiosensitise non-transformed epithelial cells or non-transformed BJ fibroblasts. Interestingly, high levels of active ATM prior to irradiation were related with increased radioresistance. To test whether active ATM in tumours prior to treatment also resulted in resistance to therapy, immunohistochemistry was performed on tumour material of patients with advanced-stage cervical cancer (n = 375) treated with (chemo)radiation. High levels of phosphorylated (p-)ATM [p = 0.006, hazard ratio (HR) = 1.817] were related to poor locoregional disease-free survival. Furthermore, high levels of p-ATM predicted shorter disease-specific survival (p = 0.038, HR = 1.418). The presence of phosphorylated 53BP1 was associated with p-ATM (p = 0.001, odds ratio = 2.206) but was not related to any clinicopathological features or survival. In conclusion, both our in vitro and patient-related findings indicate a protective role for ATM in response to (chemo)radiation in cervical cancer and point at ATM inhibition as a possible means to improve the efficacy of (chemo)radiation.
    International Journal of Cancer 02/2012; 131(9):2056-66. · 6.20 Impact Factor
  • International Journal of Gynecological Cancer 01/2012; 22(1):175. · 1.94 Impact Factor
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    ABSTRACT: The purpose of the current phase II single-arm clinical trial was to evaluate whether pretreatment with low-dose cyclophosphamide improves immunogenicity of a p53-synthetic long peptide (SLP) vaccine in patients with recurrent ovarian cancer. Patients with ovarian cancer with elevated serum levels of CA-125 after primary treatment were immunized four times with the p53-SLP vaccine. Each immunization was preceded by administration of 300 mg/m2 intravenous cyclophosphamide as a means to affect regulatory T cells (Tregs). Vaccine-induced p53-specific interferon-gamma (IFN-γ)-producing T cells evaluated by IFN-γ ELISPOT were observed in 90% (9/10) and 87.5% (7/8) of evaluable patients after two and four immunizations, respectively. Proliferative p53-specific T cells, observed in 80.0% (8/10) and 62.5% (5/8) of patients, produced both T-helper 1 and T-helper-2 cytokines. Cyclophosphamide induced neither a quantitative reduction of Tregs determined by CD4+ FoxP3+ T cell levels nor a demonstrable qualitative difference in Treg function tested in vitro. Nonetheless, the number of vaccine-induced p53-specific IFN-γ-producing T cells was higher in our study compared to a study in which a similar patient group was treated with p53-SLP monotherapy (p≤0.012). Furthermore, the strong reduction in the number of circulating p53-specific T cells observed previously after four immunizations was currently absent. Stable disease was observed in 20.0% (2/10) of patients, and the remainder of patients (80.0%) showed clinical, biochemical and/or radiographic evidence of progressive disease. The outcome of this phase II trial warrants new studies on the use of low-dose cyclophosphamide to potentiate the immunogenicity of the p53-SLP vaccine or other antitumor vaccines.
    International Journal of Cancer 12/2011; 131(5):E670-80. · 6.20 Impact Factor
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    ABSTRACT: Real-time intraoperative near-infrared fluorescence (NIRF) imaging is a promising technique for lymphatic mapping and sentinel lymph node (SLN) detection. The purpose of this technical feasibility pilot study was to evaluate the applicability of NIRF imaging with indocyanin green (ICG) for the detection of the SLN in cervical cancer. In ten patients with early stage cervical cancer, a mixture of patent blue and ICG was injected into the cervix uteri during surgery. Real-time color and fluorescence videos and images were acquired using a custom-made multispectral fluorescence camera system. Real-time fluorescence lymphatic mapping was observed in vivo in six patients; a total of nine SLNs were detected, of which one (11%) contained metastases. Ex vivo fluorescence imaging revealed the remaining fluorescent signal in 11 of 197 non-sentinel LNs (5%), of which one contained metastatic tumor tissue. None of the non-fluorescent LNs contained metastases. We conclude that lymphatic mapping and detection of the SLN in cervical cancer using intraoperative NIRF imaging is technically feasible. However, the technique needs to be refined for full applicability in cervical cancer in terms of sensitivity and specificity.
    Molecular imaging and biology: MIB: the official publication of the Academy of Molecular Imaging 10/2011; 13(5):1043-9. · 2.47 Impact Factor

Publication Stats

3k Citations
662.61 Total Impact Points

Institutions

  • 2001–2014
    • University of Groningen
      • • Department of Obstetrics and Gynaecology
      • • Analytical Biochemistry Group
      • • Department of Medical Microbiology
      • • Department of Gynecological Oncology
      • • Oncology
      • • Department of Gynecology
      • • Department of Gastroenterology and Hepatology
      Groningen, Groningen, Netherlands
  • 1999–2012
    • Universitair Medisch Centrum Groningen
      • Department of Internal Medicine
      Groningen, Groningen, Netherlands
  • 2011
    • Leiden University Medical Centre
      Leyden, South Holland, Netherlands
  • 2009
    • National Chung Cheng University
      Chia-i-hsien, Taiwan, Taiwan
  • 2004
    • Radboud University Medical Centre (Radboudumc)
      • Department of Human Genetics
      Nymegen, Gelderland, Netherlands