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Dive into the research topics where Geert A. Cirkel is active.

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Featured researches published by Geert A. Cirkel.


Annals of Surgery | 2009

Intestinal barrier dysfunction in a randomized trial of a specific probiotic composition in acute pancreatitis

Marc G. Besselink; Hjalmar C. van Santvoort; Willem Renooij; Martin De Smet; Marja A. Boermeester; K. Fischer; Harro M. Timmerman; Usama Ahmed Ali; Geert A. Cirkel; Thomas L. Bollen; Bert van Ramshorst; Alexander F. Schaapherder; Ben J. Witteman; Rutger J. Ploeg; Harry van Goor; Cornelis J. H. M. van Laarhoven; Adriaan C. Tan; Menno A. Brink; Erwin van der Harst; Peter J. Wahab; Casper H.J. van Eijck; Cornelis H.C. Dejong; Karel J. van Erpecum; L. M. A. Akkermans; Hein G. Gooszen

Objectives:To determine the relation between intestinal barrier dysfunction, bacterial translocation, and clinical outcome in patients with predicted severe acute pancreatitis and the influence of probiotics on these processes. Summary of Background data:Randomized, placebo-controlled, multicenter trial on probiotic prophylaxis (Ecologic 641) in patients with predicted severe acute pancreatitis (PROPATRIA). Methods:Excretion of intestinal fatty acid binding protein (IFABP, a parameter for enterocyte damage), recovery of polyethylene glycols (PEGs, a parameter for intestinal permeability), and excretion of nitric oxide (NOx, a parameter for bacterial translocation) were assessed in urine of 141 patients collected 24 to 48 h after start of probiotic or placebo treatment and 7 days thereafter. Results:IFABP concentrations in the first 72 hours were higher in patients who developed bacteremia (P = 0.03), infected necrosis (P = 0.01), and organ failure (P = 0.008). PEG recovery was higher in patients who developed bacteremia (PEG 4000, P = 0.001), organ failure (PEG 4000, P < 0.0001), or died (PEG 4000, P = 0.009). Probiotic prophylaxis was associated with an increase in IFABP (median 362 vs. 199 pg/mL; P = 0.02), most evidently in patients with organ failure (P = 0.001), and did not influence intestinal permeability. Overall, probiotics decreased NOx (P = 0.05) but, in patients with organ failure, increased NOx (P = 0.001). Conclusions:Bacteremia, infected necrosis, organ failure, and mortality were all associated with intestinal barrier dysfunction early in the course of acute pancreatitis. Overall, prophylaxis with this specific combination of probiotic strains reduced bacterial translocation, but was associated with increased bacterial translocation and enterocyte damage in patients with organ failure.


Annals of Surgery | 2009

Early endoscopic retrograde cholangiopancreatography in predicted severe acute biliary pancreatitis: A prospective multicenter study

Hjalmar C. van Santvoort; Marc G. Besselink; Annemarie C. de Vries; Marja A. Boermeester; K. Fischer; Thomas L. Bollen; Geert A. Cirkel; Alexander F. Schaapherder; Vincent B. Nieuwenhuijs; Harry van Goor; Cees H. Dejong; Casper H.J. van Eijck; Ben J. Witteman; Bas L. Weusten; Cees J. H. M. van Laarhoven; Peter J. Wahab; Adriaan C. Tan; Matthijs P. Schwartz; Erwin van der Harst; Miguel A. Cuesta; Peter D. Siersema; Hein G. Gooszen; Karel J. van Erpecum

Summary Background Data:The role of early endoscopic retrograde cholangiopancreatography (ERCP) in acute biliary pancreatitis (ABP) remains controversial. Previous studies have included only a relatively small number of patients with predicted severe ABP. We investigated the clinical effects of early ERCP in these patients. Methods:We performed a prospective, observational multicenter study in 8 university medical centers and 7 major teaching hospitals. One hundred fifty-three patients with predicted severe ABP without cholangitis enrolled in a randomized multicenter trial on probiotic prophylaxis in acute pancreatitis were prospectively followed. Conservative treatment or ERCP within 72 hours after symptom onset (at discretion of the treating physician) were compared for complications and mortality. Patients without and with cholestasis (bilirubin: >2.3 mg/dL [40 &mgr;mol/L] and/or dilated common bile duct) were analyzed separately. Results:Of the 153 patients, 81 (53%) underwent ERCP and 72 (47%) conservative treatment. Groups were highly comparable at baseline. Seventy-eight patients (51%) had cholestasis. In patients with cholestasis, ERCP (52/78 patients: 67%), as compared with conservative treatment, was associated with fewer complications (25% vs. 54%, P = 0.020, multivariate adjusted odds ratio [OR]: 0.35, 95% confidence interval [CI]: 0.13–0.99, P= 0.049). This included fewer patients with >30% pancreatic necrosis (8% vs. 31%, P = 0.010). Mortality was nonsignificantly lower after ERCP (6% vs. 15%, P = 0.213, multivariate adjusted OR: 0.44, 95% CI: 0.08–2.28, P = 0.330). In patients without cholestasis, ERCP (29/75 patients: 39%) was not associated with reduced complications (45% vs. 41%, P = 0.814, multivariate adjusted OR: 1.36; 95% CI: 0.49–3.76; P = 0.554) or mortality (14% vs. 17%, P = 0.754, multivariate adjusted OR: 0.78; 95% CI: 0.19–3.12, P = 0.734). Conclusions:Early ERCP is associated with fewer complications in predicted severe ABP if cholestasis is present.


The American Journal of Gastroenterology | 2007

Oral refeeding after onset of acute pancreatitis : A review of literature

Maxim S. Petrov; Hjalmar C. van Santvoort; Marc G. Besselink; Geert A. Cirkel; Menno A. Brink; Hein G. Gooszen

BACKGROUND: Oral refeeding in patients recovering from acute pancreatitis may cause pain relapse. Patients with pain relapse may be ill for prolonged periods, thereby consuming additional health care resources. We aimed to determine the incidence and risk factors of pain relapse on the basis of reviewing all studies on oral refeeding in acute pancreatitis.METHODS: Relevant literature cited in three electronic databases (Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE) as well as the abstracts of major gastroenterological meetings was reviewed. Outcome measures studied were the incidence of pain relapse and length of hospital stay.RESULTS: A total of three studies met the inclusion criteria. Sixty of 274 patients (21.9%) experienced pain relapse during the course of acute pancreatitis. In 47 of 60 (78.3%) patients pain relapse occurred within 48 h after commencement of oral refeeding. Two studies showed a significantly higher Balthazars CT score on hospital admission in patients with pain relapse, whereas all three studies found no difference in the severity scores between patients with and without pain relapse. All three studies found a significant increase in the length of hospital stay in patients with pain relapse.CONCLUSIONS: The incidence of pain relapse after oral refeeding in acute pancreatitis is relatively high. Thereby, the quest for new therapeutical modalities that can prevent pain relapse is of current importance.


British Journal of Cancer | 2014

Pharmacokinetically guided sunitinib dosing: a feasibility study in patients with advanced solid tumours

Nienke A.G. Lankheet; Jacqueline S. L. Kloth; C.G. Gadellaa-van Hooijdonk; Geert A. Cirkel; Ron H.J. Mathijssen; Martijn P. Lolkema; Jan H. M. Schellens; Emile E. Voest; Stefan Sleijfer; M.J.A. de Jonge; John B. A. G. Haanen; Jos H. Beijnen; Alwin D. R. Huitema; Neeltje Steeghs

Background:Plasma exposure of sunitinib shows large inter-individual variation. Therefore, a pharmacokinetic (PK) study was performed to determine safety and feasibility of sunitinib dosing based on PK levels.Methods:Patients were treated with sunitinib 37.5 mg once daily. At days 15 and 29 of treatment, plasma trough levels of sunitinib and N-desethyl sunitinib were measured. If the total trough level (TTL) was <50 ng ml−1 and the patient did not show any grade ⩾3 toxicity, the daily sunitinib dose was increased by 12.5 mg. If the patient suffered from grade ⩾3 toxicity, the sunitinib dose was lowered by 12.5 mg.Results:Twenty-nine out of 43 patients were evaluable for PK assessments. Grade ⩾3 adverse events were experienced in seven patients (24%) at the starting dose and in nine patients (31%) after dose escalation. TTLs were below target in 15 patients (52%) at the starting dose. Of these, five patients (17%) reached target TTL after dose escalation without additional toxicity.Conclusions:In a third of the patients that were below target TTL at standard dose, the sunitinib dose could be increased without additional toxicities. This could be the basis for future studies and the implementation of a PK-guided dosing strategy in clinical practice.


Genome Research | 2014

Genomic and transcriptomic plasticity in treatment-naïve ovarian cancer

Marlous Hoogstraat; Mirjam S. de Pagter; Geert A. Cirkel; Markus J. van Roosmalen; Timothy T. Harkins; Karen Duran; Jennifer Kreeftmeijer; Ivo Renkens; Petronella O. Witteveen; Clarence Lee; Isaac J. Nijman; Tanisha Guy; Ruben van 't Slot; Trudy N. Jonges; Martijn P. Lolkema; Marco J. Koudijs; Ronald P. Zweemer; Emile E. Voest; Edwin Cuppen; Wigard P. Kloosterman

Intra-tumor heterogeneity is a hallmark of many cancers and may lead to therapy resistance or interfere with personalized treatment strategies. Here, we combined topographic mapping of somatic breakpoints and transcriptional profiling to probe intra-tumor heterogeneity of treatment-naïve stage IIIC/IV epithelial ovarian cancer. We observed that most substantial differences in genomic rearrangement landscapes occurred between metastases in the omentum and peritoneum versus tumor sites in the ovaries. Several cancer genes such as NF1, CDKN2A, and FANCD2 were affected by lesion-specific breakpoints. Furthermore, the intra-tumor variability involved different mutational hallmarks including lesion-specific kataegis (local mutation shower coinciding with genomic breakpoints), rearrangement classes, and coding mutations. In one extreme case, we identified two independent TP53 mutations in ovary tumors and omentum/peritoneum metastases, respectively. Examination of gene expression dynamics revealed up-regulation of key cancer pathways including WNT, integrin, chemokine, and Hedgehog signaling in only subsets of tumor samples from the same patient. Finally, we took advantage of the multilevel tumor analysis to understand the effects of genomic breakpoints on qualitative and quantitative gene expression changes. We show that intra-tumor gene expression differences are caused by site-specific genomic alterations, including formation of in-frame fusion genes. These data highlight the plasticity of ovarian cancer genomes, which may contribute to their strong capacity to adapt to changing environmental conditions and give rise to the high rate of recurrent disease following standard treatment regimes.


JAMA Oncology | 2015

Increased Plasma Levels of Chemoresistance-Inducing Fatty Acid 16:4(n-3) After Consumption of Fish and Fish Oil

Laura G.M. Daenen; Geert A. Cirkel; Julia M. Houthuijzen; Johan Gerrits; Ilse Oosterom; Jeanine M.L. Roodhart; Harm van Tinteren; Kenji Ishihara; Alwin D. R. Huitema; Nanda M. Verhoeven-Duif; Emile E. Voest

IMPORTANCE Our research group previously identified specific endogenous platinum-induced fatty acids (PIFAs) that, in picomolar quantities, activate splenic macrophages leading to resistance to chemotherapy in mouse models. Fish oil was shown to contain the PIFA 16:4(n-3) (hexadeca-4,7,10,13-tetraenoic acid) and when administered to mice neutralized chemotherapy activity. OBJECTIVE Because patients with cancer frequently use fish oil supplements, we set out to determine exposure to 16:4(n-3) after intake of fish or fish oil. DESIGN, SETTING, AND PARTICIPANTS (1) In November 2011, 400 patients with cancer undergoing treatment at the University Medical Center Utrecht were surveyed to determine their use of fish oil supplements; 118 patients responded to the questionnaire (30%); (2) pharmacokinetic analysis of the 16:4(n-3) content of 6 fish oils and 4 fishes was carried out; (3) from April through November 2012, a healthy volunteer study was performed to determine 16:4(n-3) plasma levels after intake of 3 different brands of fish oil or 4 different fish species. Thirty healthy volunteers were randomly selected for the fish oil study; 20 were randomly selected for the fish study. These studies were supported by preclinical tumor experiments in mice to determine chemoresistance conducted between September 2011 and December 2012. MAIN OUTCOMES AND MEASURES (1) Rate of use of fish oil supplements among patients undergoing cancer treatment at our institution; (2) levels of 16:4(n-3) present in 3 brands of fish oil and 4 species of fish; and (3) plasma levels of 16:4(n-3) present in healthy volunteers after consuming fish oil or fish. RESULTS Eleven percent of respondents reported using omega-3 supplements. All fish oils tested contained relevant amounts of 16:4(n-3), from 0.2 to 5.7 µM. Mouse experiments showed that addition of 1 µL of fish oil to cisplatin was sufficient to induce chemoresistance, treatment having no impact on the growth rate of tumors compared with vehicle-treated controls (estimated tumor volume difference, 44.1 mm3; P > .99). When the recommended daily amount of 10 mL of fish oil was administered to healthy volunteers, rises in plasma 16:4(n-3) levels were observed, reaching up to 20 times the baseline levels. Herring and mackerel contained high levels of 16:4(n-3) in contrast to salmon and tuna. Consumption of fish with high levels of 16:4(n-3) also resulted in elevated plasma levels of 16:4(n-3). CONCLUSIONS AND RELEVANCE All tested fish oils and herring and mackerel fishes contained relevant levels of fatty acid 16:4(n-3), a fatty acid with chemotherapy-negating effects in preclinical models. After ingestion of these fish oils or fishes, 16:4(n-3) was rapidly taken up in the plasma of human volunteers. Until further data become available, fish oil and fish containing high levels of 16:4(n-3) may best be avoided on the days surrounding chemotherapy.


Acta Paediatrica | 2006

End-tidal carbon monoxide measurements in infant respiratory distress syndrome

Tannette G. Krediet; Geert A. Cirkel; Hendrik J. Vreman; Ronald J. Wong; David K. Stevenson; Floris Groenendaal; Johannes Egberts; Frank van Bel

Background: RDS involving inflammatory and oxidative processes may lead to increased production of carbon monoxide (CO). Aim: The relationship between end‐tidal CO, corrected for inhaled CO (ETCOc), and RDS severity was investigated in preterm infants as well as the value of early ETCOc measurements to predict chronic lung disease. Methods: 78 infants (30 no RDS, 32 moderate RDS, 16 severe RDS) were included. ETCOc was measured using the CO‐Stat™ End Tidal Breath Analyzer. Results: ETCOc was significantly higher in RDS compared to no RDS during the first week (p<0.05). Severity of RDS was the most significant independent variable in a stepwise regression model related to ETCOc (F‐test: 18.17). Negative predictive value of early (within first 12 h of life) ETCOc measurement (<2.5 ppm) for development of chronic lung disease was excellent (100%).


Future Oncology | 2014

Tumor heterogeneity and personalized cancer medicine: are we being outnumbered?

Geert A. Cirkel; Christa G. Gadellaa-van Hooijdonk; Marco J. Koudijs; Stefan M. Willems; Emile E. Voest

Tumor heterogeneity is regarded as a major obstacle to successful personalized cancer medicine. The lack of reliable response assays reflective of in vivo tumor heterogeneity and associated resistance mechanisms hampers identification of reliable biomarkers. By contrast, oncogene addiction and paracrine signaling enable systemic responses despite tumor heterogeneity. This strengthens researchers in their efforts towards personalized cancer medicine. Given the fact that tumor heterogeneity is an integral part of cancer evolution, diagnostic tools need to be developed in order to better understand the dynamics within a tumor. Ultra-deep sequencing may reveal future resistant clones within a (liquid) tumor biopsy. On-treatment biopsies may provide insight into intrinsic or acquired drug resistance. Subsequently, upfront combinatorial treatment or sequential therapy strategies may forestall drug resistance and improve patient outcome. Finally, innovative response assays, such as organoid cultures or patient-derived tumor xenografts, provide an extra dimension to correlate molecular profiles with drug efficacy and control cancer growth.


Oncologist | 2017

Implementation of a Multicenter Biobanking Collaboration for Next‐Generation Sequencing‐Based Biomarker Discovery Based on Fresh Frozen Pretreatment Tumor Tissue Biopsies

Sander Bins; Geert A. Cirkel; Christa G. Gadellaa-van Hooijdonk; Fleur Weeber; Isaac J. Numan; Annette H. Bruggink; Paul J. van Diest; Stefan M. Willems; Wouter B. Veldhuis; Michel M. van den Heuvel; Rob J. de Knegt; Marco J. Koudijs; Erik van Werkhoven; Ron H.J. Mathijssen; Edwin Cuppen; Stefan Sleijfer; Jan H. M. Schellens; Emile E. Voest; Marlies H.G. Langenberg; Maja J.A. de Jonge; Neeltje Steeghs; Martijn P. Lolkema

BACKGROUND The discovery of novel biomarkers that predict treatment response in advanced cancer patients requires acquisition of high-quality tumor samples. As cancer evolves over time, tissue is ideally obtained before the start of each treatment. Preferably, samples are freshly frozen to allow analysis by next-generation DNA/RNA sequencing (NGS) but also for making other emerging systematic techniques such as proteomics and metabolomics possible. Here, we describe the first 469 image-guided biopsies collected in a large collaboration in The Netherlands (Center for Personalized Cancer Treatment) and show the utility of these specimens for NGS analysis. PATIENTS AND METHODS Image-guided tumor biopsies were performed in advanced cancer patients. Samples were fresh frozen, vital tumor cellularity was estimated, and DNA was isolated after macrodissection of tumor-rich areas. Safety of the image-guided biopsy procedures was assessed by reporting of serious adverse events within 14 days after the biopsy procedure. RESULTS Biopsy procedures were generally well tolerated. Major complications occurred in 2.1%, most frequently consisting of pain. In 7.3% of the percutaneous lung biopsies, pneumothorax requiring drainage occurred. The majority of samples (81%) contained a vital tumor percentage of at least 30%, from which at least 500 ng DNA could be isolated in 91%. Given our preset criteria, 74% of samples were of sufficient quality for biomarker discovery. The NGS results in this cohort were in line with those in other groups. CONCLUSION Image-guided biopsy procedures for biomarker discovery to enable personalized cancer treatment are safe and feasible and yield a highly valuable biobank. The Oncologist 2017;22:33-40Implications for Practice: This study shows that it is safe to perform image-guided biopsy procedures to obtain fresh frozen tumor samples and that it is feasible to use these biopsies for biomarker discovery purposes in a Dutch multicenter collaboration. From the majority of the samples, sufficient DNA could be yielded to perform next-generation sequencing. These results indicate that the way is paved for consortia to prospectively collect fresh frozen tumor tissue.


JAMA Oncology | 2017

Alternating Treatment With Pazopanib and Everolimus vs Continuous Pazopanib to Delay Disease Progression in Patients With Metastatic Clear Cell Renal Cell Cancer: The ROPETAR Randomized Clinical Trial.

Geert A. Cirkel; Paul Hamberg; Stefan Sleijfer; Olaf J. L. Loosveld; M. Wouter Dercksen; Maartje Los; Marco Polee; Franchette van den Berkmortel; Maureen J. Aarts; Laurens V. Beerepoot; Gerard Groenewegen; Martijn P. Lolkema; Metin Tascilar; Johanna Elisabeth A. Portielje; Frank P. J. Peters; Heinz-Josef Klümpen; Vincent van der Noort; John B. A. G. Haanen; Emile E. Voest

Importance To our knowledge, this is the first randomized clinical trial evaluating an alternating treatment regimen in an attempt to delay disease progression in clear cell renal cell carcinoma. Objective To test our hypothesis that an 8-week rotating treatment schedule with pazopanib and everolimus delays disease progression, exhibits more favorable toxic effects, and improves quality of life when compared with continuous treatment with pazopanib. Design, Setting, and Participants This was an open-label, randomized (1:1) study (ROPETAR trial). In total, 101 patients with treatment-naive progressive metastatic clear cell renal cell carcinoma were enrolled between September 2012 and April 2014 from 17 large peripheral or academic hospitals in The Netherlands and followed for at least one year. Interventions First-line treatment consisted of either an 8-week alternating treatment schedule of pazopanib 800 mg/d and everolimus 10 mg/d (rotating arm) or continuous pazopanib 800 mg/d (control arm) until progression. After progression, patients made a final rotation to either pazopanib or everolimus monotherapy (rotating arm) or initiated everolimus (control arm). Main Outcome and Measures The primary end point was survival until first progression or death. Secondary end points included time to second progression or death, toxic effects, and quality of life. Results A total of 52 patients were randomized to the rotating arm (median [range] age, 65 [44-87] years) and 49 patients to the control arm (median [range] age, 67 [38-82] years). Memorial Sloan Kettering Cancer Center risk category was favorable in 26% of patients, intermediate in 58%, and poor in 15%. Baseline characteristics and risk categories were well balanced between arms. One-year PFS1 for rotating treatment was 45% (95% CI, 33-60) and 32% (95% CI, 21-49) for pazopanib (control). Median time until first progression or death for rotating treatment was 7.4 months (95% CI, 5.6-18.4) and 9.4 months (95% CI, 6.6-11.9) for pazopanib (control) (P = .37). Mucositis, anorexia, and dizziness were more prevalent in the rotating arm during first-line treatment. No difference in quality of life was observed. Conclusions and Relevance Rotating treatment did not result in prolonged progression-free-survival, fewer toxic effects, or improved quality of life. First-line treatment with a vascular endothelial growth factor inhibitor remains the optimal approach in metastatic clear cell renal cell carcinoma. Trial Registration clinicaltrials.gov Identifier: NCT01408004

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Emile E. Voest

Netherlands Cancer Institute

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Martijn P. Lolkema

Erasmus University Rotterdam

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Stefan Sleijfer

Erasmus University Rotterdam

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Jan H. M. Schellens

Netherlands Cancer Institute

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Alexander F. Schaapherder

Leiden University Medical Center

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Neeltje Steeghs

Netherlands Cancer Institute

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Peter J. Wahab

Erasmus University Rotterdam

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