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Dive into the research topics where Cornelis D. de Kroon is active.

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Featured researches published by Cornelis D. de Kroon.


British Journal of Obstetrics and Gynaecology | 2003

Saline contrast hysterosonography in abnormal uterine bleeding: a systematic review and meta-analysis

Cornelis D. de Kroon; Geertruida H. de Bock; Sandra Dieben; Frank Willem Jansen

Objective To assess the diagnostic accuracy of saline contrast hysterosonography in the evaluation of the uterine cavity in women complaining of abnormal uterine bleeding.


Clinical Cancer Research | 2015

POLE Proofreading Mutations Elicit an Antitumor Immune Response in Endometrial Cancer

Inge C. Van Gool; Florine A. Eggink; Luke Freeman-Mills; Ellen Stelloo; Emanuele Marchi; Marco de Bruyn; Claire Palles; Remi A. Nout; Cornelis D. de Kroon; Elisabeth M. Osse; Paul Klenerman; Carien L. Creutzberg; Ian Tomlinson; Vincent T.H.B.M. Smit; Hans W. Nijman; Tjalling Bosse; David N. Church

Purpose: Recent studies have shown that 7% to 12% of endometrial cancers are ultramutated due to somatic mutation in the proofreading exonuclease domain of the DNA replicase POLE. Interestingly, these tumors have an excellent prognosis. In view of the emerging data linking mutation burden, immune response, and clinical outcome in cancer, we investigated whether POLE-mutant endometrial cancers showed evidence of increased immunogenicity. Experimental Design: We examined immune infiltration and activation according to tumor POLE proofreading mutation in a molecularly defined endometrial cancer cohort including 47 POLE-mutant tumors. We sought to confirm our results by analysis of RNAseq data from the TCGA endometrial cancer series and used the same series to examine whether differences in immune infiltration could be explained by an enrichment of immunogenic neoepitopes in POLE-mutant endometrial cancers. Results: Compared with other endometrial cancers, POLE mutants displayed an enhanced cytotoxic T-cell response, evidenced by increased numbers of CD8+ tumor-infiltrating lymphocytes and CD8A expression, enrichment for a tumor-infiltrating T-cell gene signature, and strong upregulation of the T-cell cytotoxic differentiation and effector markers T-bet, Eomes, IFNG, PRF, and granzyme B. This was accompanied by upregulation of T-cell exhaustion markers, consistent with chronic antigen exposure. In silico analysis confirmed that POLE-mutant cancers are predicted to display more antigenic neoepitopes than other endometrial cancers, providing a potential explanation for our findings. Conclusions: Ultramutated POLE proofreading-mutant endometrial cancers are characterized by a robust intratumoral T-cell response, which correlates with, and may be caused by an enrichment of antigenic neopeptides. Our study provides a plausible mechanism for the excellent prognosis of these cancers. Clin Cancer Res; 21(14); 3347–55. ©2015 AACR.


Gynecologic Oncology | 2012

Randomized comparison of near-infrared fluorescence lymphatic tracers for sentinel lymph node mapping of cervical cancer.

Boudewijn E. Schaafsma; Joost R. van der Vorst; Katja N. Gaarenstroom; Alexander A.W. Peters; F.P.R. Verbeek; Cornelis D. de Kroon; J. Baptist Trimbos; Mariette I.E. van Poelgeest; John V. Frangioni; Cornelis J. H. van de Velde; Alexander L. Vahrmeijer

OBJECTIVE Near-infrared fluorescence imaging using indocyanine green (ICG) has recently been introduced as a novel technique for sentinel lymph node (SLN) mapping in early-stage cervical cancer. Although preclinical research has shown that ICG adsorbed to human serum albumin (ICG:HSA) improves its performance, the need for HSA has not yet been confirmed in cervical cancer patients. The current randomized study aims to determine whether ICG:HSA offers advantages over using ICG alone. METHODS Eighteen consecutive early-stage cervical cancer patients scheduled to undergo pelvic lymphadenectomy were included. Prior to surgery, 1.6 mL of 500 μM ICG:HSA or 500 μM ICG alone was injected transvaginally in 4 quadrants around the tumor. The Mini-FLARE imaging system was used for intraoperative NIR fluorescence detection and quantitation. RESULTS SLNs were identified intraoperatively in 78% of the patients. Patient and tumor characteristics were equally distributed over both treatment groups. No significant difference in signal-to-background ratio (9.3 vs. 10.1, P=.72) or average number of detected SLNs (2.9 vs 2.7, P=.84) was found between the ICG:HSA group and the ICG alone group, respectively. CONCLUSIONS In conclusion, this double-blind, randomized trial showed no advantage of ICG:HSA over ICG alone for the SLN procedure in early-stage cervical cancer. Further optimization is required to improve the intraoperative detection rate.


Journal of Ultrasound in Medicine | 2004

The Clinical Value of 3-Dimensional Saline Infusion Sonography in Addition to 2-Dimensional Saline Infusion Sonography in Women With Abnormal Uterine Bleeding Work in Progress

Cornelis D. de Kroon; Leonie A. Louwé; J. Baptist Trimbos; Frank Willem Jansen

Objective. To evaluate the clinical relevance of 3‐dimensional saline infusion sonography (3D‐SIS) in addition to conventional SIS in women with abnormal uterine bleeding suspected of having intrauterine abnormalities. Methods. All women suspected of having intrauterine abnormalities were eligible. Before 3D‐SIS, conventional SIS was performed. The results of these techniques were compared with the “combined method reference standard” (hysteroscopy, endometrial sampling, and clinical follow‐up in cases with normal SIS findings). Diagnostic characteristics (with 95% confidence intervals [CIs]) of 3D‐SIS and SIS were calculated as well as their respective accuracy in evaluating the histologic nature, the intrauterine extension, and the location of intrauterine abnormalities. Moreover, the reliability (κ value) and clinical relevance of 3D‐SIS were assessed. Results. A total of 49 women were included, and 4 women were excluded. The positive predictive values of 3D‐SIS and SIS were, respectively, 1.00 and 0.86 (95% CI, 0.72–0.99; P = .15), and the diagnostic accuracy values were 0.98 (95% CI, 0.94–1.0) and 0.91 (95% CI, 0.83–0.99; P = .08). Saline infusion sonography and 3D‐SIS were equally accurate in evaluating the histologic nature, intrauterine extent, and location of intrauterine abnormalities (respective κ values: 0.85 versus 0.93; P = .88; 0.83 versus 0.83; and 0.77 versus 0.80; P = .81). The reliability of 3D‐SIS was good: intraobserver and interobserver agreement (κ) were 0.78 and 0.72. Three women (6.7%) had the benefit of additional 3D‐SIS: in these women, SIS wrongly led to a diagnosis of intrauterine abnormalities (P = .08). Conclusions. Three‐dimensional saline infusion sonography is valid and reliable in women suspected of having intrauterine abnormalities and may indeed have relevant clinical value in addition to conventional SIS.


Current Opinion in Obstetrics & Gynecology | 2006

Saline infusion sonography in women with abnormal uterine bleeding : an update of recent findings

Cornelis D. de Kroon; Frank Willem Jansen

Purpose of review To inform about new developments concerning saline infusion sonography, especially in women suffering from abnormal uterine bleeding. Recent findings The diagnostic accuracy of saline infusion sonography has been established before the period of this review; however, recent papers support the high diagnostic accuracy and conclude saline infusion sonography is able to replace diagnostic hysteroscopy in the evaluation of the uterine cavity. The use of gel instead of saline as distension medium and the introduction of new three-dimensional inversion rendering techniques enhances the visualization of the endometrium which may improve the diagnostic accuracy of saline infusion sonography. A simple, feasible and seemingly cost-effective method of saline infusion sonography-based guided endometrial biopsy has been developed. The technique may allow saline infusion sonography based polypectomy. A classification of submucous fibroids has been proposed in order to allow more accurate, saline infusion sonography-based, preoperative selection of fibroids suitable for hysteroscopic resection. Summary The development of saline infusion sonography-based guided biopsies allows saline infusion sonography to compete with vaginoscopic operative hysteroscopy. Additional comparative trials are needed in order to finalize the decision about the proper method of the assessment of the uterine cavity.


Contraception | 2003

Follow-up visits after IUD-insertion: sense or nonsense? A technology assessment study to analyze the effectiveness of follow-up visits after IUD insertion

Karlijn Neuteboom; Cornelis D. de Kroon; Marianne Dersjant-Roorda; Frank Willem Jansen

The objective of this study is to evaluate whether regular follow-up after insertion of an IUD protects against the risk and side effects of this contraceptive device. To study the effectiveness of the follow-up visits done after IUD insertion, we compared a group of women with regular follow-up visits (group A: after 6 weeks, 3, 6 and 12 months) with women who had non-regular follow-up visits (group B: after 6 weeks and annually) for pregnancy, expulsion rates and discontinuation. A total of 280 women were included (group A: 199, group B: 81). Three pregnancies and 2 unnoticed expulsions were observed. The detection rate of an unnoticed expulsion is 0.35 and 0.11 per 100 visits for, respectively, the visit 6 weeks after insertion and all successive visits. Women in group A came significantly more frequently for unscheduled visits [relative risk (RR): 1.6; 95% confidence interval (CI): 1.03-2.4]. The number of discontinuations, pregnancies and expulsions did not differ between groups, but women in group B had their IUD removed earlier (p < 0.01). We conclude that regular follow-up after the insertion of an IUD is not effective.


Journal of Minimally Invasive Gynecology | 2009

The impact of alternative treatment for abnormal uterine bleeding on hysterectomy rates in a tertiary referral center.

Heleen van Dongen; Amy G. van de Merwe; Cornelis D. de Kroon; Frank Willem Jansen

STUDY OBJECTIVE The purpose of this study was to estimate the influence of alternatives to hysterectomy for abnormal uterine bleeding (AUB) on hysterectomy rates. DESIGN Retrospective cohort study. Canadian Task Force II-2. SETTING University hospital. PATIENTS Premenopausal patients with AUB. INTERVENTIONS Medical records of all premenopausal patients treated for AUB in our university clinic between January 1, 1995, and December 31, 2004, were reviewed. Patients were identified based on (specific) diagnostic and therapy codes used in the registry system of the hospital. The total number of placements of levonorgestrel-releasing intrauterine device (LNG-IUD), hysteroscopic surgery, and hysterectomies performed/year was estimated. In addition, the course of treatment of each patient was assessed. MEASUREMENTS AND MAIN RESULTS A total of 640 patients received surgery and 246 LNG-IUDs were placed. The proportion of endometrial ablations decreased significantly over time (p <.001), whereas hysteroscopic polyp or myoma removal (p =.030) and insertion of LNG-IUD (p <.001) both increased. The proportion of patients receiving hysterectomy for AUB as their first therapy decreased significantly (p =.005) from 40.6% to 31.4%, although the total number of patients receiving hysterectomy remained similar (p =.449). The 5-year intervention-free percentage for LNG-IUD was 70.6% (SD = 3.3%), for hysteroscopic polyp or myoma removal 75.5% (SD = 3.3%), and for endometrial ablation 78.0% (SD = 4.3%; p =.067). CONCLUSION Despite the introduction of alternative therapies, the total hysterectomy rate in the management of AUB did not decrease in our clinic.


PLOS ONE | 2015

Galectin-1, -3 and -9 Expression and Clinical Significance in Squamous Cervical Cancer

Simone Punt; Victor L. Thijssen; Johannes Vrolijk; Cornelis D. de Kroon; Arko Gorter; Ekaterina S. Jordanova

Galectins are proteins that bind β-galactoside sugars and provide a new type of potential biomarkers and therapeutic targets in cancer. Galectin-1, -3 and -9 have become the focus of different research groups, but their expression and function in cervical cancer is still unclear. The aim of this study was to determine the phenotype of galectin-1, -3 and -9 expressing cells and the association with clinico-pathological parameters in cervical cancer. Galectin expression was scored in tumor cells, tumor epithelium infiltrating immune cells and stromal cells in squamous cervical cancer (n = 160). Correlations with clinico-pathological parameters and survival were studied according to the REMARK recommendations. We additionally investigated whether the galectins were expressed by tumor cells, fibroblasts, macrophages and T cells. Galectin-1 and -9 were both expressed by tumor cells in 11% of samples, while 84% expressed galectin-3. Strong galectin-1 expression by tumor cells was an independent predictor for poor survival (hazard ratio: 8.02, p = 0.001) and correlated with increased tumor invasion (p = 0.032) and receiving post-operative radiotherapy (p = 0.020). Weak and positive tumor cell galectin-3 expression were correlated with increased and decreased tumor invasion, respectively (p = 0.012). Tumor cell expression of galectin-9 showed a trend toward improved survival (p = 0.087). The predominant immune cell type expressing galectin-1, -3 and -9 were CD163+ macrophages. Galectin-1 and -3 were expressed by a minor population of T cells. Galectin-1 was mainly expressed by fibroblasts in the tumor stroma. To conclude, while tumor cell expression of galectin-9 seemed to represent a beneficial response, galectin-1 expression might be used as a marker for a more aggressive anti-cancer treatment.


Molecular Cancer | 2015

Correlations between immune response and vascularization qRT-PCR gene expression clusters in squamous cervical cancer

Simone Punt; Jeanine J. Houwing-Duistermaat; Iris A. Schulkens; Victor L. Thijssen; Elisabeth M. Osse; Cornelis D. de Kroon; Arjan W. Griffioen; Gert Jan Fleuren; Arko Gorter; Ekaterina S. Jordanova

BackgroundThe tumour microenvironment comprises a network of immune response and vascularization factors. From this network, we identified immunological and vascularization gene expression clusters and the correlations between the clusters. We subsequently determined which factors were correlated with patient survival in cervical carcinoma.MethodsThe expression of 42 genes was investigated in 52 fresh frozen squamous cervical cancer samples by qRT-PCR. Weighted gene co-expression network analysis and mixed-model analyses were performed to identify gene expression clusters. Correlations and survival analyses were further studied at expression cluster and single gene level.ResultsWe identified four immune response clusters: ‘T cells’ (CD3E/CD8A/TBX21/IFNG/FOXP3/IDO1), ‘Macrophages’ (CD4/CD14/CD163), ‘Th2’ (IL4/IL5/IL13/IL12) and ‘Inflammation’ (IL6/IL1B/IL8/IL23/IL10/ARG1) and two vascularization clusters: ‘Angiogenesis’ (VEGFA/FLT1/ANGPT2/ PGF/ICAM1) and ‘Vessel maturation’ (PECAM1/VCAM1/ANGPT1/SELE/KDR/LGALS9). The ‘T cells’ module was correlated with all modules except for ‘Inflammation’, while ‘Inflammation’ was most significantly correlated with ‘Angiogenesis’ (p < 0.001). High expression of the ‘T cells’ cluster was correlated with earlier TNM stage (p = 0.007). High CD3E expression was correlated with improved disease-specific survival (p = 0.022), while high VEGFA expression was correlated with poor disease-specific survival (p = 0.032). Independent predictors of poor disease-specific survival were IL6 (hazard ratio = 2.3, p = 0.011) and a high IL6/IL17 ratio combined with low IL5 expression (hazard ratio = 4.2, p = 0.010).Conclusions‘Inflammation’ marker IL6, especially in combination with low levels of IL5 and IL17, was correlated with poor survival. This suggests that IL6 promotes tumour growth, which may be suppressed by a Th17 and Th2 response. Measuring IL6, IL5 and IL17 expression may improve the accuracy of predicting prognosis in cervical cancer.


Oncotarget | 2018

Folate receptor-α targeted near-infrared fluorescence imaging in high-risk endometrial cancer patients: a tissue microarray and clinical feasibility study

Leonora S.F. Boogerd; Charlotte E.S. Hoogstins; Katja N. Gaarenstroom; Cornelis D. de Kroon; Jogchum J. Beltman; Tjalling Bosse; Ellen Stelloo; Jaap Vuyk; Philip S. Low; Jacobus Burggraaf; Alexander L. Vahrmeijer

Objective Detection and resection of all malignant lesions is pivotal in staging and cytoreductive surgery (CRS) of endometrial cancer (EC). Intraoperative EC detection could be enhanced using OTL-38, a fluorescent-labelled folate receptor-α (FRα) targeted imaging agent. The objectives of this study were to investigate which subgroups of high-risk EC patients express FRα and assess feasibility of intraoperative EC detection using OTL-38. Results FRα expression on TMA was significantly correlated with tumor type (p < 0.01). Eighty-two percent of serous and clear cell carcinomas showed FRα expression. Four patients were enrolled in the clinical study. Using fluorescence imaging all omental (n = 3) and lymph node (LN) metastases (n = 16) could be clearly identified, including one otherwise undetected omental metastasis. However, false-positive fluorescence was identified in 17/50 non-metastatic LNs, caused by OTL-38 targeting of FRβ, expressed by tumor-associated activated macrophages. Conclusions This study describes high FRα expression in serous and clear cell EC and demonstrates the first experience of intraoperative FRα-targeted tumor detection in patients with these subtypes of EC. Although all metastases could be clearly identified using OTL-38, the role of tumor-associated macrophages should be further evaluated. Methods Immunohistochemical (IHC) staining of FRα expression was performed on tissue micro arrays (TMA) of 116 patients with high-risk EC features. Patients with either serous or clear cell EC, planned for staging or CRS, were eligible for inclusion in the clinical study and received an intravenous dose of 0.0125 mg/kg OTL-38, 2-3 hours prior to surgery. Resected lesions, identified by standard-of-care and/or fluorescence imaging, were histopathologically assessed for FRα and tumor status.

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Frank Willem Jansen

Leiden University Medical Center

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Arko Gorter

Leiden University Medical Center

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Simone Punt

Leiden University Medical Center

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Elisabeth M. Osse

Leiden University Medical Center

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Gert Jan Fleuren

Leiden University Medical Center

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J. Baptist Trimbos

Leiden University Medical Center

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Sandra Dieben

Leiden University Medical Center

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Tjalling Bosse

Leiden University Medical Center

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Victor L. Thijssen

VU University Medical Center

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