Renske Fles
Netherlands Cancer Institute
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Renske Fles.
The Journal of Pathology | 2009
Caroline Holm; Marleen Kok; Rob Michalides; Renske Fles; Rutger Koornstra; Jelle Wesseling; Michael Hauptmann; Jacques Neefjes; Johannes L. Peterse; Olle Stål; Göran Landberg; Sabine C. Linn
Phosphorylation of oestrogen receptor α at serine 305 (ERαS305‐P) induces tamoxifen resistance in experimental studies, but does not influence response to other endocrine agents, such as fulvestrant. We evaluated ERαS305‐P using immunohistochemistry in 377 breast carcinomas from premenopausal participants of a randomized trial (n = 248) and patients with advanced disease (n = 129). Among the premenopausal patients, adjuvant tamoxifen improved recurrence‐free survival (RFS) for ERαS305‐P‐negative tumours (multivariate HR = 0.53, 95% CI 0.32–0.86, p = 0.010), but not for ERαS305‐P‐positive tumours (multivariate HR = 1.01, 95% CI 0.33–3.05, p = 0.99) (interaction p = 0.131). Notably, ERαS305‐P was not significantly associated with RFS in patients not treated with tamoxifen (multivariate HR = 0.64, 95% CI 0.30–1.37, p = 0.248), indicating that ERαS305‐P is a marker for treatment outcome rather than tumour progression. Given the direct experimental link between ERαS305‐P and tamoxifen resistance and these first clinical data suggesting that premenopausal patients with ERαS305‐P‐positive breast cancer are resistant to adjuvant tamoxifen, further research is encouraged to study whether alternative endocrine treatment should be considered for this subgroup. Copyright
The Journal of Pathology | 2009
Marleen Kok; Rutger Koornstra; Tania C Margarido; Renske Fles; Nicola J. Armstrong; Sabine C. Linn; Laura J. van 't Veer; Britta Weigelt
Tumourigenic subpopulations with stem cell‐like features have been identified in breast tumours and breast cancer cell lines. The hormone receptor status, molecular characteristics and clinical significance of these cells are still matters of debate. Enrichment for tumourigenic cells without the requirement of surface markers can be achieved by the in vitro mammosphere culture assay. Here we compared the hormone receptor status and genome‐wide gene expression profiles of mammospheres derived from four oestrogen‐receptor (ER) positive breast cancer cell lines with those of the respective parental cells. Immunohistochemistry and gene expression profiling revealed a significant reduction in the expression of progesterone receptor, proliferation and cell cycle regulated genes in mammospheres when compared to parental cell lines. The 200 most differentially expressed genes between mammospheres and parental cell lines were used to generate a ‘mammosphere‐derived’ gene set. Hierarchical clustering of gene expression profiles of two independent cohorts of primary ER‐positive cancers based on the ‘mammosphere‐derived’ gene set revealed that the subgroup of breast cancers with profiles similar to those of mammospheres has a significantly longer overall survival. In conclusion, tumour‐initiating breast cancer cells grown in mammospheres seem to reside in a quiescent state. ER‐positive breast cancers with expression profiles similar to those of mammospheres have a better outcome, providing evidence in support of the concept that outcome of patients with ER‐positive disease is for a large part determined by cell cycle and proliferation activity. Copyright
PLOS ONE | 2013
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
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
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.
Genes, Chromosomes and Cancer | 2010
Renske Fles; Wilhelmina E. Hoogendoorn; Inge Platteel; Caroline E. Scheerman; Gerie de Leeuw-Mantel; Marian J.E. Mourits; Harry Hollema; Flora E. van Leeuwen; Hester van Boven; Petra M. Nederlof
Tamoxifen has been a very effective treatment for breast cancer for several decades, however, at the same time increases the risk of endometrial cancer, especially after prolonged exposure. In addition, tamoxifen has been associated with a higher proportion of unfavorable uterine tumor subtypes (carcinosarcomas and serous adenocarcinomas) with worse survival. We investigated whether endometrial tumors, which developed after prolonged tamoxifen treatment for breast cancer, are genetically different from endometrial tumors without preceding tamoxifen exposure. Array CGH was used on archival formalin‐fixed paraffin embedded endometrial tumors to determine genomic aberrations. We compared the genomic profiles of 52 endometrial tumors from breast cancer patients after long‐term (≥2 years) tamoxifen use (endometrioid adenocarcinomas, n = 26; carcinosarcomas, n = 14; and serous adenocarcinomas, n = 12) with endometrial tumors from unexposed breast cancer patients (n = 45). Genomic profiles were correlated with tamoxifen exposure, tumor subtypes, and histopathological characteristics of the endometrial tumors. The common uterine corpus cancers of the endometrioid subtype show few genomic aberrations. Tumors with many genomic aberrations were in general ER‐negative. In contrast, carcinosarcomas and serous adenocarcinomas showed many aberrations; however, they were indistinguishable from each other. Tumors that developed after prolonged tamoxifen use did not show more or different aberrations than unexposed tumors. This was true for all tumor subtypes. Thus, endometrial carcinomas that develop after prolonged tamoxifen use cannot be distinguished from nonusers on basis of their tumor genomic profile.
The Breast | 2012
Marleen Kok; Rutger Koornstra; S. Mook; Michael Hauptmann; Renske Fles; Mphm Jansen; E. M. J. J. Berns; Sabine C. Linn; L van't Veer
BACKGROUND Breast cancer patients with node positive disease can have an excellent outcome with tamoxifen only. It is unclear whether analysing both the 70-gene signature and hormone receptors provides superior prediction of outcome in tamoxifen-treated patients than either alone. METHODS Three series were evaluated: 121 patients (81% node positive) received adjuvant tamoxifen, 151 patients did not receive tamoxifen (10% node positive) and 92 patients received tamoxifen for metastatic disease. The 70-gene signature was analysed using MammaPrint. Oestrogen receptor (ER) and progesterone receptor (PR) immunohistochemistry was evaluated following St. Gallen Consensus (Highly Endocrine Responsive: ER and PR ≥ 50%, Incompletely Endocrine Responsive: ER and/or PR low or either one absent). RESULTS In patients treated with adjuvant tamoxifen, both the 70-gene signature (adjusted for Endocrine Response Categories HR 2.17, 95%CI 1.01-4.66) as well as the Endocrine Response Categories (adjusted for 70-gene signature HR 6.35, 95%CI 1.90-21.3) were associated with breast-cancer-specific-survival (BCSS). Also in patients treated with tamoxifen for metastatic disease, combined analysis of the 70-gene signature and ER/PR revealed additional value (multivariate Cox regression, p = 0.013). In patients who did not receive tamoxifen, only the 70-gene signature was associated with outcome. CONCLUSION In the series analysed, the 70-gene signature was mainly a prognostic factor, while ER and PR levels were mainly associated with outcome after tamoxifen. Combination of these three factors may improve outcome prediction in tamoxifen-treated patients.
PLOS ONE | 2012
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.
BMC Medical Education | 2010
Renske Fles; Maarten A. Wildeman; Beni Sulistiono; Sofia Mubarika Haryana; I. Bing Tan
BackgroundNasopharyngeal carcinoma (NPC) is one of the leading causes of cancer death in Indonesia. At initial diagnosis, 80% of the patients present with advanced stage disease. In Indonesia, primary medical care is generally provided by the health care centres; named Puskesmas. The lack of knowledge of various aspects of NPC of the General practitioners (GPs) working in these centers might contribute to the diagnostic delay. The aim of this study was to assess the knowledge of these GPs on different aspects of NPC including symptoms, risk factors and incidence.MethodsOne hundred six GPs in the Puskesmas in the Yogyakarta province were subjected to a questionnaire on different aspects of NPC based on literature and interviews with Head and Neck Surgeons.ResultsAll GPs approached participated and in total 106 questionnaires were filled in. All participants were aware of NPC as a disease and 89% confirmed that it is a serious problem in Indonesia. However, 50% of the participants believed NPC has a low incidence in their region. The question on early symptoms gave a mean 4.2 answers of which 50% were incorrect.The GPs provided a total of 318 answers when asked for the risk factors of NPC, 75% of which were incorrect. Fifty seven GPs (54%) stated that they did not receive sufficient education on NPC at the university and insufficient knowledge was gained during daily practice. Ninety-two percent of the GPs were interested in additional education, preferably in form of lectures, meetings or folders.ConclusionThis study revealed that GPs in the Puskesmas in Yogyakarta lack knowledge on all aspects of NPC. This is an important finding as NPC is endemic in Indonesia and the Puskesmas are the institutions which provide primary medical health care in the country. Further education of the GPs in these endemic areas could be a first step to increase the rate of early detection. Therefore, we suggest 1) to conduct a medical awareness campaign for GPs on the most important subjects concerning NPC, and 2) as soon as NPC awareness among GPs has risen, provide further education on the risk factors, the early symptoms and the incidence, education to the community. We propose to extend this study to other areas in Indonesia (i.e. Jakarta, Surabaya, Central Java), using models that have been developed in Yogyakarta.
PLOS ONE | 2014
Sharon D. Stoker; Maarten A. Wildeman; Renske Fles; Sagung Rai Indrasari; Camelia Herdini; Pieter L. Wildeman; Judi van Diessen; Maesadji Tjokronagoro; I. Bing Tan
Introduction Nasopharyngeal carcinoma (NPC) has a high incidence in Indonesia. Previous study in Yogyakarta revealed a complete response of 29% and a median overall survival of less than 2 years. These poor treatment outcome are influenced by the long diagnose-to-treatment interval to radiotherapy (DTI) and the extended overall treatment time of radiotherapy (OTT). This study reveals insight why the OTT and DTI are prolonged. Method All patients treated with curative intent radiotherapy for NPC between July 2011 until October 2012 were included. During radiotherapy a daily diary was kept, containing information on DTI, missed radiotherapy days, the reason for missing and length of OTT. Results Sixty-eight patients were included. The median DTI was 106 days (95% CI: 98−170). Fifty-nine patients (87%) finished the treatment. The median OTT for radiotherapy was 57 days (95% CI: 57–65). The main reason for missing days was an inoperative radiotherapy machine (36%). Other reasons were patient’s poor condition (21%), public holidays (14%), adjustment of the radiation field (7%), power blackout (3%), inoperative treatment planning system (2%) and patient related reasons (9%). Patient’s insurance type was correlated to DTI in disadvantage for poor people. Conclusion Yogyakarta has a lack of sufficient radiotherapy units which causes a delay of 3–4 months, besides the OTT is extended by 10–12 days. This influences treatment outcome to a great extend. The best solution would be creating sufficient radiotherapy units and better management in health care for poor patients. The growing economy in Indonesia will expectantly in time enable these solutions, but in the meantime solutions are needed. Solutions can consist of radiation outside office hours, better maintenance of the facilities and more effort from patient, doctor and nurse to finish treatment in time. These results are valuable when improving cancer care in low and middle income countries.