Geert J.L.H. van Leenders
Erasmus University Medical Center
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Featured researches published by Geert J.L.H. van Leenders.
European Urology | 2014
Leonard P. Bokhorst; Chris H. Bangma; Geert J.L.H. van Leenders; Jan J. Lous; Sue Moss; Fritz H. Schröder; Monique J. Roobol
BACKGROUNDnLarge randomized screening trials provide an estimation of the effect of screening at a population-based level. The effect of screening for individuals, however, is diluted by nonattendance and contamination in the trial arms.nnnOBJECTIVEnTo determine the prostate cancer (PCa) mortality reduction from screening after adjustment for nonattendance and contamination.nnnDESIGN, SETTING, AND PARTICIPANTSnA total of 34,833 men in the core age group, 55-69 yr, were randomized to a screening or control arm in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC). Prostate-specific antigen (PSA) testing was offered to all men in the screening arm at 4-yr intervals. A prostate biopsy was offered to men with an elevated PSA. The primary end point was PCa-specific mortality.nnnOUTCOME MEASUREMENTS AND STATISTICAL ANALYSISnNonattendance was defined as nonparticipation in the screening arm. Contamination in the control arm was defined as receiving asymptomatic PSA testing or a prostate biopsy in the absence of symptoms. Relative risks (RRs) were calculated with an intention to screen (ITS) analysis and after correction for nonattendance and contamination using a method that preserves the benefits obtained by randomization.nnnRESULTS AND LIMITATIONSnThe ITS analysis resulted in an RR of 0.68 (95% confidence interval [CI], 0.53-0.89) in favor of screening at a median follow-up of 13 yr. Correction for both nonattendance and contamination resulted in an RR of 0.49 (95% CI, 0.27-0.87) in favor of screening.nnnCONCLUSIONSnPCa screening as conducted in the Rotterdam section of the ERSPC can reduce the risk of dying from PCa up to 51% for an individual man choosing to be screened repeatedly compared with a man who was not screened. This benefit of screening should be balanced against the harms of overdiagnosis and subsequent overtreatment.nnnTRIAL REGISTRATIONnISRCTN49127736.
European Urology | 2013
Chris H. Bangma; Stacy Loeb; Martijn Busstra; X. Zhu; Samira el Bouazzaoui; Jeanine Refos; Kirstin A. Van Der Keur; Stephen Tjin; Conja G.A.M. Franken; Geert J.L.H. van Leenders; E.C. Zwarthoff; Monique J. Roobol
BACKGROUNDnWe previously reported the preliminary findings from a feasibility study of bladder cancer (BCa) screening with urinary molecular markers (Bladder Cancer Urine Marker Project [BLU-P]) that has now been terminated.nnnOBJECTIVEnTo report the final results from BLU-P to determine whether mass screening for BCa is feasible and useful.nnnDESIGN, SETTING, AND PARTICIPANTSnBLU-P was a Dutch population-based study initiated in 2008 to evaluate BCa screening. A total of 6500 men were invited to participate in the study, 1984 (30.5%) agreed, and 1747 (88.1%) men completed the protocol and were followed for 2 yr.nnnINTERVENTIONnThe screening protocol included home hematuria testing followed by molecular markers-nuclear matrix protein 22 (NMP22), microsatellite analysis (MA), fibroblast growth factor receptor 3 (FGFR3) mutation snapshot assay, and a custom methylation-specific (MLPA) test-to determine the need for cystoscopy.nnnOUTCOME MEASUREMENTS AND STATISTICAL ANALYSISnOutcomes included the number of cystoscopies and the cancer detection rate within and outside the protocol, as determined by linkage to national registries.nnnRESULTS AND LIMITATIONSnOverall, 409 men (23.4%) tested positive for hematuria and underwent molecular testing. Current smokers (n=295 [17%]) and past smokers (n=998 [58%]) were significantly more likely to test positive for hematuria than nonsmokers. Seventy-one of 75 men (94.6%) with positive molecular markers underwent the recommended cystoscopy. Four BCas and one kidney tumor were detected through this sequential protocol, whereas one BCa and one kidney tumor were missed through the screening program. Limitations include the possibility of healthy subject bias.nnnCONCLUSIONSnFor BCa screening, use of a sequential protocol with home hematuria testing followed by molecular markers substantially reduced the number of cystoscopy recommendations compared with dipstick testing alone. A sequential screening approach may help minimize unnecessary invasive follow-up testing, with very few missed cancers. Nevertheless, this mass screening program had a very low diagnostic yield in an unselected asymptomatic European male population.
BJUI | 2017
Arnout R. Alberts; Monique J. Roobol; Frank-Jan H. Drost; Geert J.L.H. van Leenders; Leonard P. Bokhorst; Chris H. Bangma; I. Schoots
To assess the value of risk‐stratification based on magnetic resonance imaging (MRI) and prostate‐specific antigen density (PSA‐D) in reducing unnecessary biopsies without missing Gleason pattern 4 prostate cancer in men on active surveillance (AS).
Urology | 2014
Jorie Buijs; Lucas Maillette de Buy Wenniger; Geert J.L.H. van Leenders; Joanne Verheij; Ilze van Onna; Bettina E. Hansen; Marianne J. Van Heerde; Nanda Krak; Ulrich Beuers; Marco J. Bruno; Henk R. van Buuren
OBJECTIVEnTo evaluate the occurrence and histopathologic characteristics of immunoglobulin G4 (IgG4)-related prostatic involvement in patients diagnosed with autoimmune pancreatitis.nnnMETHODSnNine cases of IgG4-related prostatitis were identified among 117 men in the autoimmune pancreatitis and IgG4-associated cholangitis patient databases in 2 tertiary hospitals. Clinical information was retrieved, and available prostatic tissue samples and 18 prostatitis control samples were evaluated for characteristic IgG4-related disease (IgG4-RD) features: maximum number of IgG4-positive cells per high-power field; dense lymphoplasmacytic infiltrate; fibrosis, arranged at least focally in a storiform pattern; phlebitis with or without obliteration of the lumen; and increased number of eosinophils.nnnRESULTSnThe aspecific sign of urine retention was commonly present in IgG4-RD patients with prostatic involvement. In these patients with IgG4-related prostatitis, the median number of IgG4-positive cells in prostatic tissue was 150 (interquartile range, 20-150) per high-power field compared with a median of 3 (interquartile range, 1-11) in control patients (Pxa0= .008). Dense lymphoplasmacytic infiltrate was observed in most (86% in cases and 72% in control patients) tissue samples independent of the underlying cause of prostatitis. Fibrosis in at least a focally storiform pattern was seen rarely in both groups, and (obliterative) phlebitis was absent in all patients. Furthermore, eosinophil numbers were more often elevated in patients with IgG4-RD compared with controls (Pxa0<.001). In 2 cases, amelioration of the prostatitis symptoms on corticosteroid treatment was documented.nnnCONCLUSIONnProstatic involvement might not be rare in patients with pancreatic or biliary IgG4-RD. Clinicians should consider this disease entity in patients with IgG4-RD and prostatic symptoms.
Cancer Research | 2015
Veerander P.S. Ghotra; Shuning He; Geertje van der Horst; Steffen Nijhoff; Hans de Bont; Annemarie N. Lekkerkerker; Richard Antonius Jozef Janssen; Guido Jenster; Geert J.L.H. van Leenders; A. Marije M. Hoogland; Esther I. Verhoef; Zuzanna Baranski; Jiangling Xiong; Bob van de Water; Gabri van der Pluijm; B. Ewa Snaar-Jagalska; Erik H. J. Danen
Improved targeted therapies are needed to combat metastatic prostate cancer. Here, we report the identification of the spleen kinase SYK as a mediator of metastatic dissemination in zebrafish and mouse xenograft models of human prostate cancer. Although SYK has not been implicated previously in this disease, we found that its expression is upregulated in human prostate cancers and associated with malignant progression. RNAi-mediated silencing prevented invasive outgrowth in vitro and bone colonization in vivo, effects that were reversed by wild-type but not kinase-dead SYK expression. In the absence of SYK expression, cell surface levels of the progression-associated adhesion receptors integrin α2β1 and CD44 were diminished. RNAi-mediated silencing of α2β1 phenocopied SYK depletion in vitro and in vivo, suggesting an effector role for α2β1 in this setting. Notably, pharmacologic inhibitors of SYK kinase currently in phase I-II trials for other indications interfered similarly with the invasive growth and dissemination of prostate cancer cells. Our findings offer a mechanistic rationale to reposition SYK kinase inhibitors for evaluation in patients with metastatic prostate cancer.
European Urology | 2015
Leonard P. Bokhorst; Ries Kranse; Lionne Venderbos; Jolanda W. Salman; Geert J.L.H. van Leenders; Fritz H. Schröder; Chris H. Bangma; Monique J. Roobol
UNLABELLEDnScreening for prostate cancer (PCa) results in a favorable stage shift. However, even if screening did not result in a clinically apparent lower stage or grade, it might still lead to less disease recurrence after treatment with curative intent (radical prostatectomy [RP] and radiation therapy [RT]) because the tumor had less time to develop outside the prostate. The outcome after treatment could also differ because of variations in treatment quality (eg, radiation dosage/adjuvant hormonal therapy). To test these hypotheses, we compared differences in the treatment quality of the screening and control arms of the European Randomized Study of Screening for Prostate Cancer (ERSPC) Rotterdam and disease-free survival (DFS) after curative treatment in PCa patients with similar stage and grade. A total of 2595 men were initially treated with RP or RT. In the control arm, RT was more often combined with hormonal therapy; treatment dosage was often ≥69Gy. This most likely resulted from changes over time in treatment that coincided with the later detection in the control arm. DFS was higher in the screening arm in all risk groups. After correction for lead time, these differences were minimal, however. We concluded that treatment quality differed between the screening and control arms of the ERSPC Rotterdam. RT quality was especially superior in the control arm with higher dosages and more often RT in combination with hormonal therapy. Despite these differences favoring the control arm, DFS differences were minimal.nnnPATIENT SUMMARYnWe looked at differences in prostate cancer (PCa) treatment and outcome after PCa treatment in men diagnosed after screening and men diagnosed after normal clinical practice. Treatment differed with superior treatment given to men diagnosed in normal clinical practice. We propose a likely explanation for this apparently counterintuitive finding (progressive insight combined with, on average, a later detection of tumors in unscreened men). Although unscreened men received better treatment, this advantage seemed to be outweighed by the advantage associated with the earlier detection, on average, of the tumor in screened men.nnnTRIAL REGISTRATIONnISRCTN49127736.
European Urology | 2016
Roberta R. Ruela-de-Sousa; Elmer Hoekstra; A. Marije M. Hoogland; Karla C. S. Queiroz; Maikel P. Peppelenbosch; Andrew Stubbs; Karin Juliane Pelizzaro-Rocha; Geert J.L.H. van Leenders; Guido Jenster; Hiroshi Aoyama; Carmen V. Ferreira; G. Fuhler
BACKGROUNDnLow-risk patients suffering from prostate cancer (PCa) are currently placed under active surveillance rather than undergoing radical prostatectomy. However, clear parameters for selecting the right patient for each strategy are not available, and new biomarkers and treatment modalities are needed. Low-molecular-weight protein tyrosine phosphatase (LMWPTP) could present such a target.nnnOBJECTIVEnTo correlate expression levels of LMWPTP in primary PCa to clinical outcome, and determine the role of LMWPTP in prostate tumor cell biology.nnnDESIGN, SETTING, AND PARTICIPANTSnAcid phosphatase 1, soluble (ACP1) expression was analyzed on microarray data sets, which were subsequently used in Ingenuity Pathway Analysis. Immunohistochemistry was performed on a tissue microarray containing material of 481 PCa patients whose clinicopathologic data were recorded. PCa cell line models were used to investigate the role of LMWPTP in cell proliferation, migration, adhesion, and anoikis resistance.nnnOUTCOME MEASUREMENTS AND STATISTICAL ANALYSISnThe association between LMWPTP expression and clinical and pathologic outcomes was calculated using chi-square correlations and multivariable Cox regression analysis. Functional consequences of LMWPTP overexpression or downregulation were determined using migration and adhesion assays, confocal microscopy, Western blotting, and proliferation assays.nnnRESULTS AND LIMITATIONSnLMWPTP expression was significantly increased in human PCa and correlated with earlier recurrence of disease (hazard ratio [HR]:1.99; p<0.001) and reduced patient survival (HR: 1.53; p=0.04). Unbiased Ingenuity analysis comparing cancer and normal prostate suggests migratory propensities in PCa. Indeed, overexpression of LMWPTP increases PCa cell migration, anoikis resistance, and reduces activation of focal adhesion kinase/paxillin, corresponding to decreased adherence.nnnCONCLUSIONSnOverexpression of LMWPTP in PCa confers a malignant phenotype with worse clinical outcome. Prospective follow-up should determine the clinical potential of LMWPTP overexpression.nnnPATIENT SUMMARYnThese findings implicate low-molecular-weight protein tyrosine phosphatase as a novel oncogene in prostate cancer and could offer the possibility of using this protein as biomarker or target for treatment of this disease.
BMC Cancer | 2018
René Böttcher; C.F. Kweldam; Julie Livingstone; Emilie Lalonde; Takafumi N. Yamaguchi; Vincent Huang; Fouad Yousif; Michael Fraser; Robert G. Bristow; Theodorus van der Kwast; Paul C. Boutros; Guido Jenster; Geert J.L.H. van Leenders
BackgroundInvasive cribriform and intraductal carcinoma (CR/IDC) is associated with adverse outcome of prostate cancer patients. The aim of this study was to determine the molecular aberrations associated with CR/IDC in primary prostate cancer, focusing on genomic instability and somatic copy number alterations (CNA).MethodsWhole-slide images of The Cancer Genome Atlas Project (TCGA, Nxa0=u2009260) and the Canadian Prostate Cancer Genome Network (CPC-GENE, Nxa0=u2009199) radical prostatectomy datasets were reviewed for Gleason score (GS) and presence of CR/IDC. Genomic instability was assessed by calculating the percentage of genome altered (PGA). Somatic copy number alterations (CNA) were determined using Fisher-Boschloo tests and logistic regression. Primary analysis were performed on TCGA (Nu2009=u2009260) as discovery and CPC-GENE (Nu2009=u2009199) as validation set.ResultsCR/IDC growth was present in 80/260 (31%) TCGA and 76/199 (38%) CPC-GENE cases. Patients with CR/IDC and ≥ GS 7 had significantly higher PGA than men without this pattern in both TCGA (2.2 fold; pxa0=u20090.0003) and CPC-GENE (1.7 fold; pxa0=u20090.004) cohorts. CR/IDC growth was associated with deletions of 8p, 16q, 10q23, 13q22, 17p13, 21q22, and amplification of 8q24. CNAs comprised a total of 1299 gene deletions and 369 amplifications in the TCGA dataset, of which 474 and 328 events were independently validated, respectively. Several of the affected genes were known to be associated with aggressive prostate cancer such as loss of PTEN, CDH1, BCAR1 and gain of MYC. Point mutations in TP53, SPOP and FOXA1were also associated with CR/IDC, but occurred less frequently than CNAs.ConclusionsCR/IDC growth is associated with increased genomic instability clustering to genetic regions involved in aggressive prostate cancer. Therefore, CR/IDC is a pathologic substrate for progressive molecular tumour derangement.
European Urology | 2017
Arnout R. Alberts; I. Schoots; Leonard P. Bokhorst; Frank-Jan H. Drost; Geert J.L.H. van Leenders; Gabriel P. Krestin; Roy S. Dwarkasing; Jelle O. Barentsz; Fritz H. Schröder; Chris H. Bangma; Monique J. Roobol
BACKGROUNDnThe harm of screening (unnecessary biopsies and overdiagnosis) generally outweighs the benefit of reducing prostate cancer (PCa) mortality in men aged ≥70 yr. Patient selection for biopsy using risk stratification and magnetic resonance imaging (MRI) may improve this benefit-to-harm ratio.nnnOBJECTIVEnTo assess the potential of a risk-based strategy including MRI to selectively identify men aged ≥70 yr with high-grade PCa.nnnDESIGN, SETTING, AND PARTICIPANTSnThree hundred and thirty-seven men with prostate-specific antigen ≥3.0 ng/ml at a fifth screening (71-75 yr) in the European Randomized study of Screening for Prostate Cancer Rotterdam were biopsied. One hundred and seventy-nine men received six-core transrectal ultrasound biopsy (TRUS-Bx), while 158 men received MRI, 12-core TRUS-Bx, and fusion TBx in case of Prostate Imaging Reporting and Data System ≥3 lesions.nnnOUTCOME MEASUREMENTS AND STATISTICAL ANALYSISnThe primary outcome was the overall, low-grade (Gleason Score 3+3) and high-grade (Gleason Score ≥ 3+4) PCa rate. Secondary outcome was the low- and high-grade PCa rate detected by six-core TRUS-Bx, 12-core TRUS-Bx, and MRI ± TBx. Tertiary outcome was the reduction of biopsies and low-grade PCa detection by upfront risk stratification with the Rotterdam Prostate Cancer Risk Calculator 4.nnnRESULTS AND LIMITATIONSnFifty-five percent of men were previously biopsied. The overall, low-grade, and high-grade PCa rates in biopsy naïve men were 48%, 27%, and 22%, respectively. In previously biopsied men these PCa rates were 25%, 20%, and 5%. Sextant TRUS-Bx, 12-core TRUS-Bx, and MRI ± TBx had a similar high-grade PCa rate (11%, 12%, and 11%) but a significantly different low-grade PCa rate (17%, 28%, and 7%). Rotterdam Prostate Cancer Risk Calculator 4-based stratification combined with 12-core TRUS-Bx ± MRI-TBx would have avoided 65% of biopsies and 68% of low-grade PCa while detecting an equal percentage of high-grade PCa (83%) compared with a TRUS-Bx all men approach (79%).nnnCONCLUSIONSnAfter four repeated screens and ≥1 previous biopsies in half of men, a significant proportion of men aged ≥70 yr still harbor high-grade PCa. Upfront risk stratification and the combination of MRI and TRUS-Bx would have avoided two-thirds of biopsies and low-grade PCa diagnoses in our cohort, while maintaining the high-grade PCa detection of a TRUS-Bx all men approach. Further studies are needed to verify these results.nnnPATIENT SUMMARYnProstate cancer screening reduces mortality but is accompanied by unnecessary biopsies and overdiagnosis of nonaggressive tumors, especially in repeatedly screened elderly men. To tackle these drawbacks screening should consist of an upfront risk-assessment followed by magnetic resonance imaging and transrectal ultrasound-guided biopsy.
International Journal of Urology | 2017
Arnout R. Alberts; Leonard P. Bokhorst; C.F. Kweldam; I. Schoots; Theo H. van der Kwast; Geert J.L.H. van Leenders; Monique J. Roobol
A total of 15 men who died of prostate cancer had cT1/2 biopsy Gleason score ≤6 prostate cancer at prevalence screening in the European Randomized study of Screening for Prostate Cancer Rotterdam. Our objective was to explain (part of) these prostate cancer deaths by undergrading with the classical Gleason score.