A Y N Schouten-van Meeteren

VU medisch centrum, Amsterdam, North Holland, Netherlands

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Publications (12)32.71 Total impact

  • Article: Outcome after first relapse in children with acute lymphoblastic leukemia: a report based on the Dutch Childhood Oncology Group (DCOG) relapse all 98 protocol.
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    ABSTRACT: We report on the treatment of children and adolescents with acute lymphoblastic leukemia (ALL) in first relapse. The protocol focused on: (1) Intensive chemotherapy preceding allogeneic stem cell transplantation (SCT) in early bone marrow relapse; (2) Rotational chemotherapy in late relapse, without donor; (3) Postponement of cerebro-spinal irradiation in late isolated CNS relapse; and (4) Treatment in very late bone marrow relapse with chemotherapy only. From January 1999 until July 2006 all 158 Dutch pediatric patients with ALL in first relapse were recorded. Ninety-nine patients were eligible; 54 patients with early and 45 with late relapse. Eighteen patients had an isolated extra-medullary relapse; 69 patients had bone marrow involvement only. Five-years EFS rates for early and late relapses were 12% and 35%, respectively. For early relapses 5 years EFSs were 25% for patients transplanted; 0% for non-transplanted patients. For late relapses 5 years EFS was 64% for patients treated with chemotherapy only, and 16% for transplanted patients. For very late relapses EFS was 58%. Our data suggest the superiority of SCT for early relapse patients. For late relapses a better outcome is achieved with chemotherapy only using the rotational chemotherapy scheme. The most important factor for survival was interval between first CR and occurrence of the first relapse.
    Pediatric Blood & Cancer 02/2011; 57(2):210-6. · 1.89 Impact Factor
  • Article: Contrast-enhancement of the anterior eye segment in patients with retinoblastoma: correlation between clinical, MR imaging, and histopathologic findings.
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    ABSTRACT: AES contrast-enhancement is recognized in a substantial number of retinoblastoma-affected eyes. We retrospectively investigated the histopathologic basis of AES contrast-enhancement on MR images in retinoblastoma. Pretreatment contrast-enhanced MR images were obtained from 42 children with retinoblastoma. Forty-two enucleated eyes were included in this study, AES enhancement was evaluated by using a 3-point score, and these data were correlated with clinical, MR imaging, and histopathologic findings. Additionally, 14 specimens were immunohistochemically analyzed for CD31, VEGF, and Flt-1 expression. Statistical correlations with AES enhancement were assessed by using a linear-by-linear association test and univariate and multivariate ordinal regressions. The degree of abnormal AES enhancement was moderate in 15 (36%) eyes and strong in 14 (33%) eyes, whereas 13 (31%) eyes showed normal AES enhancement. In multivariate analysis, the degree of AES enhancement showed statistically significant correlations with iris surface-vessel count (P = .05) and optic nerve invasion (P = .04) in the enucleated eye and with tumor volume (P = .02) as detected on MR imaging. No significant associations between AES enhancement and VEGF expression in the iris were observed. Flt-1 (P = .04) staining in iris stroma and IA as detected with CD31 staining (P = .009) both yielded a statistically significant positive correlation with abnormal AES enhancement. The degree of abnormal AES enhancement on MR imaging in retinoblastoma reflects angiogenesis in the iris. AES enhancement is also a hallmark of advanced retinoblastoma because its degree correlates with tumor volume and optic nerve invasion.
    American Journal of Neuroradiology 10/2009; 31(2):237-45. · 2.93 Impact Factor
  • Article: Novel RUNX1 mutations in familial platelet disorder with enhanced risk for acute myeloid leukemia: clues for improved identification of the FPD/AML syndrome.
    Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 10/2009; 24(1):242-6. · 8.30 Impact Factor
  • Article: Behavioural functioning of retinoblastoma survivors.
    J van Dijk, K J Oostrom, S M Imhof, A C Moll, A Y N Schouten-van Meeteren, P D Bezemer, J Huisman
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    ABSTRACT: To assess behavioural problems in retinoblastoma (RB) survivors. This population-based cross-sectional study included 148 RB survivors (8-35 years), registered in the Dutch national RB register. Survivors and parents were asked to fill in behavioural questionnaires. Prevalence rates were computed, based on both self-reports and proxy reports. One-sample T-tests were applied to analyse differences compared with healthy reference samples. Multiple regression analyses were performed to identify predictors for behavioural problems within the RB sample. Between-group differences varied across informants and across age groups. Parents reported significantly elevated total problem behaviour in 30% of their offspring (aged 8-17 years); this against 9% in adolescents (12-17 years) and 12% in adults (18-35 years) based on self-report. Parental reports showed significantly elevated rates of (1) internalising problems in boys and (2) somatic complaints in both girls and boys. Self-reports indicate significantly lowered levels of (1) externalising problems in adolescent and adult women and (2) thought problems in female adolescents and in adult men. Especially survivors who suffered hereditary RB, who had undergone more intensive treatment, and who came from a single-parent family were identified to be at most behavioural risk. Perception of severity and the nature of behavioural problems seem to differ between beholder, and to vary between age groups, if not between life stages. Health professionals should be aware that especially those who are confronted with hereditary RB and who subsequently undergo intensive treatment, and who grow up in broken families, run the risk of developing behavioural difficulties.
    Psycho-Oncology 07/2008; 18(1):87-95. · 3.34 Impact Factor
  • Article: International retinoblastoma staging system helps to bridge the gap.
    Pediatric Blood & Cancer 04/2008; 50(3):733. · 1.89 Impact Factor
  • Article: Retinal dysplasia mimicking intraocular tumor: MR imaging findings with histopathologic correlation.
    P de Graaf, P van der Valk, A C Moll, S M Imhof, A Y N Schouten-van Meeteren, J A Castelijns
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    ABSTRACT: We report a 6-month-old boy who presented with unilateral leukocoria, retinal detachment, and a retrolental mass in a microphthalmic eye based on retinal dysplasia with concurrent optic nerve aplasia. Dysplastic retinal tissue, a rare congenital defect, may create a clinical and radiologic picture of an intraocular mass closely resembling tumor tissue. MR imaging findings with histopathologic correlation are presented to facilitate discrimination of the more common causes of leukocoria.
    American Journal of Neuroradiology 11/2007; 28(9):1731-3. · 2.93 Impact Factor
  • Article: Stage of presentation and visual outcome of patients screened for familial retinoblastoma: nationwide registration in the Netherlands.
    S M Imhof, A C Moll, A Y N Schouten-van Meeteren
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    ABSTRACT: In the Netherlands a comprehensive programme for screening just after birth for familial retinoblastoma is taking place. In this report the stage of the disease at the time of detection, by way of screening, and the long term visual outcome in these patients was evaluated. A nationwide, retrospective study. From January 1992-July 2004, patients at risk for familial retinoblastoma were screened 1-2 weeks after birth, and investigated for laterality, Reese-Ellsworth classification/International Classification of Retinoblastoma, macular involvement, age of primary retinoblastoma, initial therapy, and visual outcome. 17 patients were diagnosed with familial retinoblastoma. 88.3% developed bilateral, 11.7% unilateral retinoblastoma. Of the 34 eyes, 56% were R-E group I, 16% were group II A-B, 16% were group III A-B, 9% were group IV, 3% were group V. Using the International Classification of Retinoblastoma, 72% were group A, 19% were group B, 6% were group C, 3% were group E. The visual outcome revealed 73.5% of eyes with 20/20-20/40, 26.5% eyes with < or = 20/100-no light perception; 5.9% of eyes were enucleated, all other eyes were treated with local or conservative treatment methods. Of all eyes, 59% had extramacular retinoblastoma, 98% of patients had at least one eye with extramacular retinoblastoma. Most familial retinoblastoma patients present as a R-E group I or group A when screened within 2 weeks after birth. Nearly 90% of patients had a long term visual acuity of 20/20-20/40. Despite the common occurrence of macula involvement, bilateral macula involvement was infrequent, and since most eyes were salvaged, good vision was obtained in the majority of patients.
    British Journal of Ophthalmology 07/2006; 90(7):875-8. · 2.90 Impact Factor
  • Article: Immunocytochemical detection of deoxycytidine kinase in pediatric malignancies in relation to in vitro cytarabine sensitivity.
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    ABSTRACT: Deoxycytidine kinase (dCK) is essential for the phosphorylation of cytarabine (ara-C), a deoxycytidine analog active against acute leukemias. Resistance to ara-C has been linked to dCK deficiency. In this study we determined the expression of the dCK protein in pediatric malignancies, using immunocytochemistry and related the expression levels to in vitro ara-C sensitivity (measured with the MTT-assay). dCK expression was high in the AML and retinoblastoma samples, in the ALL samples dCK expression ranged from low to very high. The brain tumor samples expressed low levels of dCK. AML was significantly more sensitive in vitro to ara-C compared to ALL (p = 0.03). Retinoblastoma and brain tumor cells were extremely resistant in vitro, we were unable to detect more than 50% ara-C induced cell kill in the majority of samples. Samples were combined in groups according to dCK expression. Samples with low dCK expression were significantly more resistant to ara-C compared to samples with high dCK expression. In conclusion, dCK expression varies between individual samples and between different types of malignancies and may play a role in resistance to ara-C in particular tumor types.
    Nucleosides Nucleotides &amp Nucleic Acids 11/2004; 23(8-9):1351-6. · 0.90 Impact Factor
  • Article: Fluorine-18 fluorodeoxyglucose positron emission tomography (PET) to detect vital retinoblastoma in the eye: preliminary experience.
    A C Moll, O S Hoekstra, S M Imhof, E F Comans, A Y N Schouten-van Meeteren, P van der Valk, M Boers
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    ABSTRACT: To report our first experience with FDG-PET in the detection of vital retinoblastoma. Four newly diagnosed retinoblastoma patients, two treated retinoblastoma patients, and four control patients were enrolled in this pilot study. F18-FDG uptake was assessed in the light of clinical and histopathological features. PET discriminated between new patients and controls, although tumor uptake varied widely. PET added no useful information with regard to possible vital tissue in tumor scars in the eye of the two treated retinoblastoma patients. Moreover, PET findings did not correlate with clinical or histopathological features. Based on this small pilot study, F18-PET shows little promise in the detection of retinoblastoma. More research on other radiofarmacons is recommended.
    Ophthalmic Genetics 04/2004; 25(1):31-5. · 0.93 Impact Factor
  • Article: Retinoblastoma and retinal astrocytoma: unusual double tumour in one eye.
    S M Imhof, A C Moll, P Van Der Valk, A Y N Schouten-Van Meeteren
    British Journal of Ophthalmology 01/2003; 86(12):1441-2. · 2.90 Impact Factor
  • Article: Overview: chemotherapy for retinoblastoma: an expanding area of clinical research.
    A Y N Schouten-Van Meeteren, A C Moll, S M Imhof, A J P Veerman
    Medical and Pediatric Oncology 07/2002; 38(6):428-38.
  • Article: Features of proliferation and in vitro drug resistance in central primitive neuro-ectodermal tumours.
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    ABSTRACT: The features of proliferation in brain tumours are related with clinical prognosis for several types of brain tumours, especially gliomas. For childhood central primitive neuro-ectodermal tumours (cPNET), including medulloblastoma, this relation has previously been unclear. The aim of this study is to investigate the relationship between proliferative features of cPNET and in vitro resistance for cytostatic drugs measured with the 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium-bromide (MTT) assay. Tumour material was obtained from 23 surgical specimens of cPNET. The expression of the proliferation markers Ki-67, proliferating cell nuclear antigen (PCNA) and cyclin D1 was determined with immunohistochemistry, while S-phase and DNA ploidy were analysed by flowcytometric analysis cell scan (FACS). The in vitro resistance for 10 cytostatic drugs was determined with the MTT assay. Drug resistance levels were available in 19 (83%) of the 23 samples with a complete profile of 10 cytostatic drugs tested in 14 samples. An excellent correlation in drug resistance scores was found between pharmacologically related drugs. The Ki-67 staining in 20 samples varied from 10 to 60% and from 30 to 100% for PCNA. Cyclin D1 staining was negative in 11 out of 18 samples. The S-phase in 16 samples ranged from 2 to 16%. Increased staining of Ki-67 was related with actinomycin D sensitivity (r -.603; P=0.022), while cells with a higher S-phase percentage were more resistant to ifosfamide (r.952; P<0.0001). In vitro drug resistance testing of central primitive neuro-ectodermal tumours (PNET) is feasible with the MTT assay. Ifosfamide resistance was related with increased Ki-67 and S-phase percentage of the tumour cells, while increased Ki-67 was also related with actinomycin D sensitivity. These findings suggest a cell cycle dependent activity of cytostatic drugs in vitro.
    Neuropathology and Applied Neurobiology 07/2002; 28(3):200-9. · 3.80 Impact Factor