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Dive into the research topics where Maarten A. Wildeman is active.

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Featured researches published by Maarten A. Wildeman.


Clinical Cancer Research | 2012

Cytolytic Virus Activation Therapy for Epstein-Barr Virus–Driven Tumors

Maarten A. Wildeman; Zlata Novalić; Sandra A. W. M. Verkuijlen; Hedy Juwana; Alwin D. R. Huitema; I. Bing Tan; Jaap M. Middeldorp; Jan Paul de Boer; Astrid E. Greijer

Purpose: Nasopharyngeal carcinoma (NPC) is causally linked to Epstein–Barr virus (EBV) infection. Because all tumor cells carry EBV, the virus itself is a potential target for therapy. In these tumor cells, EBV hides in a latent state and expresses only a few non-immunogenic proteins for EBV maintenance and contributes to tumor growth. We developed a cytolytic virus activation (CLVA) therapy for NPC treatment, reactivating latent EBV, triggering immune recognition, and inducing susceptibility to antiviral therapy. Experimental Design: CLVA therapy combines gemcitabine (GCb) and valproic acid (VPA) for virus activation and tumor clearance with (val)ganciclovir (GCV) as the antiviral drug to block virus replication and kill proliferating virus-infected cells. CLVA treatment was optimized and validated in NPC cell lines and subsequently tested in 3 Dutch patients with NPC that was refractory to conventional treatment. Results: In NPC cell lines, both GCb and VPA can induce the lytic cycle of EBV. Their combination resulted in a strong synergistic effect. The addition of GCV resulted in higher cytotoxicity compared with chemotherapy alone, which was not observed in EBV-negative cells. CLVA therapy was analyzed in 3 patients with end-stage NPC. Patients developed increased levels of viral DNA in the circulation originating from apoptotic tumor cells, had disease stabilization, and experienced improved quality of life. Conclusions: Our results in the initial CLVA-treated patients indicate that the therapy had a biological effect and was well tolerated with only moderate transient toxicity. This new virus-specific therapy could open a generic approach for treatment of multiple EBV-associated malignancies. Clin Cancer Res; 18(18); 5061–70. ©2012 AACR.


International Journal of Cancer | 2009

Molecular markers predict outcome in squamous cell carcinoma of the head and neck after concomitant cisplatin-based chemoradiation.

Guido B. van den Broek; Maarten A. Wildeman; Coen R. N. Rasch; Nicola J. Armstrong; Ed Schuuring; Adrian C. Begg; Leendert Looijenga; Rik J. Scheper; Jacqueline E. van der Wal; Lorian Menkema; Paul J. van Diest; Alfons J. M. Balm; Marie-Louise F. van Velthuysen; Michiel W. M. van den Brekel

Not all patients with squamous cell carcinomas of the head and neck (HNSCC) benefit from concurrent cisplatin‐based chemoradiation, but reliable predictive markers for outcome after chemoradiation are scarce. We have investigated potential prognostic biomarkers for outcome in a large group of patients. Ninety‐one tumor biopsies taken from consecutive HNSCC patients were evaluated for protein expression on a tissue microarray. Using immunohistochemistry, 18 biomarkers, involved in various cellular pathways were investigated. Univariable and multivariable proportional hazard analyses were performed to investigate associations between each individual marker and outcome. In addition, the global test was used to test all variables simultaneously and selected combinations of markers for an overall association with local control. Univariable analysis showed statistically significant increased relative risks of RB, P16 and MRP2 for local control and MDR1 and HIF‐1α for overall survival. MRP2, MDR1 and P16 levels were positively associated with outcome whereas RB and HIF‐1α had a negative relationship. Using Goemans global testing no combination of markers was identified that was associated with local control. Grouping the markers according to their function revealed an association between a combination of 3 markers (P16, P21 and P27) and outcome (p = 0.05) was found. In the multivariable analysis, MRP2 and RB remained significant independent predictive markers for local control. This study describes the prognostic value of biomarkers for the outcome in patients uniformly treated with concurrent chemoradiation. MRP2 and RB were found to be associated with outcome in patients treated with concurrent chemoradiation.


European Archives of Oto-rhino-laryngology | 2011

Photodynamic therapy of early stage oral cavity and oropharynx neoplasms: an outcome analysis of 170 patients

Baris Karakullukcu; Kim van Oudenaarde; Marcel P. Copper; W.M.C. Klop; Robert L.P. van Veen; Maarten A. Wildeman; I. Bing Tan

The indications of photodynamic therapy (PDT) of oral cavity and oropharynx neoplasms are not well defined. The main reason is that the success rates are not well established. The current paper analyzes our institutional experience of early stage oral cavity and oropharynx neoplasms (Tis-T2) to identify the success rates for each subgroup according to T stage, primary or non-primary treatment and subsites. In total, 170 patients with 226 lesions are treated with PDT. From these lesions, 95 are primary neoplasms, 131 were non-primaries (recurrences and multiple primaries). The overall response rate is 90.7% with a complete response rate of 70.8%. Subgroup analysis identified oral tongue, floor of mouth sites with more favorable outcome. PDT has more favorable results with certain subsites and with previously untreated lesions. However, PDT can find its place for treating lesions in previously treated areas with acceptable results.


Head & Neck Oncology | 2009

Photodynamic therapy in the therapy for recurrent/persistent nasopharyngeal cancer

Maarten A. Wildeman; Heike J. Nyst; Baris Karakullukcu; Bing I. Tan

To determine the efficacy of Photodynamic therapy of patients with recurrent Nasopharyngeal Carcinoma we reviewed all available literature.Since the treatment options for recurrent or persistent Nasopharyngeal Carcinoma are limited, the survival rates poor and the complications severe; there is definitely a place for alternative treatment modalities with more efficacy and less morbidity. Photodynamic therapy (PDT) has the potential to be a very effective local treatment modality for recurrent or persistent nasopharyngeal cancer, without the severe side effects seen with re-irradiation. This review shows all reported results of Photodynamic therapy in the treatment for Nasopharyngeal Carcinoma.


PLOS ONE | 2013

Primary Treatment Results of Nasopharyngeal Carcinoma (NPC) in Yogyakarta, Indonesia

Maarten A. Wildeman; Renske Fles; Camelia Herdini; Rai S. Indrasari; Andrew Vincent; Maesadji Tjokronagoro; Sharon D. Stoker; Johan Kurnianda; Baris Karakullukcu; Kartika Widayati Taroeno-Hariadi; O. Hamming-Vrieze; Jaap M. Middeldorp; Bambang Hariwiyanto; Sofia Mubarika Haryana; I. Bing Tan

Introduction Nasopharyngeal Carcinoma (NPC) is a major health problem in southern and eastern Asia. In Indonesia NPC is the most frequent cancer in the head and neck area. NPC is very sensitive to radiotherapy resulting in 3-year disease-free and overall survival of approximately 70% and 80%, respectively. Here we present routine treatment results in a prospective study on NPC in a top referral; university hospital in Indonesia. Methods All NPC patients presenting from September 2008 till January 2011 at the ear, nose and throat (ENT) department of the Dr. Sardjito General Hospital, Universitas Gadjah Mada, Yogyakarta, Indonesia, were possible candidates. Patients were included if the biopsy was a histological proven NPC without distant metastasis and were assessed during counselling sessions prior to treatment, as being able to complete the entire treatment. Results In total 78 patients were included for treatment analysis. The median time between diagnosis and start of radiotherapy is 120 days. Forty-eight (62%) patients eventually finished all fractions of radiotherapy. The median duration of the radiotherapy is 62 days for 66 Gy. Median overall survival is 21 months (95% CI 18–35) from day of diagnosis. Conclusion The results presented here reveal that currently the treatment of NPC at an Indonesian hospital is not sufficient and cannot be compared to the treatment results in literature. Main reasons for these poor treatment results are (1) a long waiting time prior to the start of radiotherapy, (2) the extended overall duration of radiotherapy and (3) the advanced stage of disease at presentation.


Oral Oncology | 2013

Lower mortality from nasopharyngeal cancer in The Netherlands since 1970 with differential incidence trends in histopathology.

Melina Arnold; Maarten A. Wildeman; Otto Visser; Henrike E. Karim-Kos; Jaap M. Middeldorp; Renske Fles; I. Bing Tan; Jan Willem Coebergh

OBJECTIVE Nasopharyngeal carcinoma (NPC) is rare in western countries albeit affected by common and unrelated phenomena: smoking less in men, more in women and immigration from China and North Africa. We studied trends in NPC incidence, tumour morphology, survival and mortality in order to assess progress against this cancer. MATERIALS AND METHODS A trend analysis was performed with nationwide incidence and survival data (from The Netherlands Cancer registry in 1989-2009), followed by analysis of mortality (data from Statistics Netherlands) covering the period 1970-2009, and calculating estimated percentages of change (EAPC) in both. According to the WHO classification we distinguished keratinizing SCC (WHO-I), differentiated (WHO-IIA) and undifferentiated (WHO-IIB) non-keratinizing carcinoma. RESULTS NPC incidence significantly decreased since 1989, especially in males (EAPC 1989-2009: -1.3; 95% CI: -2.5, -0.2) and in patients with keratinizing SCC (WHO-I) (EAPC: -3.6; 95% CI: -5.3, -1.8). By contrast, the incidence of differentiated non-keratinizing tumours (WHO-IIA) significantly increased in the same period (EAPC: 9.6; 95% CI: 5.6, 13.5). One- and three-year relative survival, as an indicator of disease-specific survival increased slightly from 79% to 81% and from 57% to 65% since 1989. NPC mortality significantly decreased since 1970 (EAPC: -1.2; 95% CI: -1.8, -0.5) and more pronounced since 1989 (EAPC: -3.0; 95% CI: -4.3, -1.6). CONCLUSION During the past two decades, the incidence of NPC in The Netherlands decreased mainly by less keratinizing, supposedly smoking-related NPC (WHO-I). However, the incidence of non-keratinizing NPC (WHO-IIA, B) increased, most likely due to EBV infection and thus related to higher immigration levels of people from high-incidence areas.


Trials | 2011

Can an online clinical data management service help in improving data collection and data quality in a developing country setting

Maarten A. Wildeman; Jeroen Zandbergen; Andrew Vincent; Camelia Herdini; Jaap M. Middeldorp; Renske Fles; O. Dalesio; Emile van der Donk; I. Bing Tan

BackgroundData collection by Electronic Medical Record (EMR) systems have been proven to be helpful in data collection for scientific research and in improving healthcare. For a multi-centre trial in Indonesia and the Netherlands a web based system was selected to enable all participating centres to easily access data. This study assesses whether the introduction of a Clinical Trial Data Management service (CTDMS) composed of electronic Case Report Forms (eCRF) can result in effective data collection and treatment monitoring.MethodsData items entered were checked for inconsistencies automatically when submitted online. The data were divided into primary and secondary data items. We analysed both the total number of errors and the change in error rate, for both Primary and Secondary items, over the first five month of the trial.ResultsIn the first five months 51 patients were entered. The Primary data error rate was 1.6%, whilst that for Secondary data was 2.7% against acceptable error rates for analysis of 1% and 2.5% respectively.ConclusionThe presented analysis shows that after five months since the introduction of the CTDMS the Primary and Secondary data error rates reflect acceptable levels of data quality. Furthermore, these error rates were decreasing over time. The digital nature of the CTDMS, as well as the online availability of that data, gives fast and easy insight in adherence to treatment protocols. As such, the CTDMS can serve as a tool to train and educate medical doctors and can improve treatment protocols.


Laryngoscope | 2009

Radiotherapy in Laryngeal Carcinoma : Can a Panel of 13 Markers Predict Response?

Maarten A. Wildeman; Johan H. Gibcus; Michael Hauptmann; Adrian C. Begg; Marie Louise F Van Velthuysen; F. Hoebers; Mirjam F. Mastik; Ed Schuuring; Jacqueline E. van der Wal; Michiel W. M. van den Brekel

To find biomarkers associated with response to radiotherapy in laryngeal cancer that can be used together with clinical parameters to improve outcome prediction.


Photodiagnosis and Photodynamic Therapy | 2012

Temoporfin mediated photodynamic therapy in patients with local persistent and recurrent nasopharyngeal carcinoma after curative radiotherapy: A feasibility study

Heike J. Nyst; Maarten A. Wildeman; S.R. Indrasari; Baris Karakullukcu; R.L.P. van Veen; Marlinda Adham; Fiona A. Stewart; Pc Levendag; Henricus J. C. M. Sterenborg; I.B. Tan

BACKGROUND The treatment of persistent and recurrent nasopharyngeal carcinoma (NPC) remains a challenge, especially in Indonesia. We investigated the safety and efficacy of temoporfin mediated photodynamic therapy (PDT) for patients with local persistent and recurrent NPC. MATERIAL AND METHODS Twenty-two patients with persistent and recurrent NPC (maximum tumor depth < 10mm) underwent PDT under local anesthesia with use of a nasopharyngeal light applicator. Three different drug doses and light intervals have been administered: treatment arm A: 0.15 mg/kg Foscan; 96 h drug-light interval; B: drug dose of 0.10 mg/, 48 h drug-light interval; C: drug dose of 0.075 mg/kg, 24 h drug-light interval. Toxicity was measured by using the CTCAE 3.1 scale. RESULTS Arm A consisted of eight patients, arms B and C consisted of seven patients. The treatment procedure was well tolerable under local anesthesia. The most common grade III toxicities for all groups is headache (n = 7; 33%). No grade IV toxicity was seen. One patient died 2 days after treatment due to a misdiagnosed pneumonia. In 17 of the 22 patients a biopsy was performed after 40 weeks and showed no tumor in all biopsies. Arm A seems, in addition to comparable toxicity, clinically more effective than arms B and C. CONCLUSION The present study demonstrated that temoporfin mediated photodynamic therapy is a relatively simple technique that can be utilized to treat residual or recurrent nasopharyngeal cancer, restricted locally to the nasopharynx.


PLOS ONE | 2012

Short-Term Effect of Different Teaching Methods on Nasopharyngeal Carcinoma for General Practitioners in Jakarta, Indonesia

Maarten A. Wildeman; Renske Fles; Marlinda Adham; Ika D. Mayangsari; Ilse Luirink; Mara Sandberg; Andrew Vincent; Faiziah Fardizza; Zanil Musa; Armiyanto; Jaap M. Middeldorp; Geerten Gerritsen; Ronny Suwanto; I. Bing Tan

In Indonesia, Nasopharyngeal Carcinoma (NPC) is the most frequent cancer of the head and neck region. At first presentation in the hospital most patients already have advanced NPC. Our previous study showed that general practitioners (GPs) working in Yogyakarta, Indonesia lack the knowledge necessary for early detection of NPC. By providing training on early symptoms of NPC we hope that the diagnosis and referral will occur at an earlier stage. Here we assess the current NPC knowledge levels of GPs in Jakarta, evaluate improvement after training, compare the effectiveness of two training formats, and estimate the loss of recall over a two week period. Methods Two Indonesian GPs visited 31 Primary Health Care Centres (PHCCs) and provided a lecture on NPC. The alternative format consisted of a symposium at the Universitas Indonesia, Jakarta, presented by local head and neck surgeons, with all GPs in the region being invited. To evaluate the effect of both formats a questionnaire was conducted before and after. Results The lecture in the PHCCs was attended by 130 GPs. Sixty-six GPs attended the training in the university hospital and 40 GPs attended both. Pre training the NPC knowledge level was poor with an average of 1.6 symptoms being correctly identified out of a potential maximum of 12, this was increased to 4.9 post training (p<0.0001). GPs attending the PHCC course recorded a greater increase in correct symptoms than those attending the symposium (3.8 vs. 2.8; p = 0.01). After a two week period the knowledge levels had declined slightly from 5.5 correctly identified symptoms to 4.2 (p = 0.25). Conclusion These results confirm our findings regarding GPs insufficient knowledge of NPC. Lectures in the PHCC and a symposium have both been proven to be effective training tools in the education of GPs.

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I. Bing Tan

Netherlands Cancer Institute

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Renske Fles

Netherlands Cancer Institute

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Jaap M. Middeldorp

VU University Medical Center

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Baris Karakullukcu

Netherlands Cancer Institute

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Sharon D. Stoker

Netherlands Cancer Institute

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Astrid E. Greijer

VU University Medical Center

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