Cor de Kroon

Dr. Cor de Kroon

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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 January 2022 in Gynecologic Oncology
Verified
Journal Article
Open access
ALAlicia León-Castillo
Alicia León-Castillo
NHNanda Horeweg
Nanda Horeweg
EPElke E.M. Peters
Elke E.M. Peters
TRTessa Rutten
Tessa Rutten
NHNatalja ter Haar
Natalja ter Haar
TBTjalling Bosse
Tjalling Bosse
The clinical role of the molecular endometrial cancer (EC) classification has not been fully explored in patients staged with lymphadenectomy or without adjuvant treatment, conditions that could potentially moderate the prognostic value of the classification. We aimed to evaluate the clinical outcome of the molecular subgroups in patients with high-grade EC staged by lymphadenectomy and those without adjuvant treatment. DNA-sequencing for the detection of pathogenic POLE-exonuclease domain mutations and immunohistochemistry for mismatch repair (MMR) proteins and p53 expression were performed on 412 high-grade EC from the Danish Gynaecological Cancer Database (2005-2012) to classify them as POLE-ultramutated (POLEmut), MMR-deficient (MMRd), p53-mutant (p53abn), or no specific molecular profile (NSMP). Patients with stage IV or residual disease after surgery were excluded. Kaplan-Meier method, log-rank test and Cox proportional hazard models were used for analysis. Molecular analysis was successful in 367 EC; 251 patients had undergone lymphadenectomy. Five-year recurrence rates in this subgroup of patients was 36.7% for women with p53abn EC, 0.0% for POLEmut EC, 13.4% for MMRd EC and 42.9% for NSMP EC (p < 0.001). Similar results were observed among stage IA-IB patients. Among patients without adjuvant treatment (n = 264), none with POLEmut EC (n = 26) had a recurrence. The molecular EC classification has strong prognostic value, independent of clinicopathological factors, also among high-grade EC patients staged by lymphadenectomy and those without adjuvant treatment. The unfavourable prognosis of early-stage p53abn EC is not due to undetected lymph node metastasis, and the indolent behaviour of POLEmut EC is independent of adjuvant treatment.

12 March 2021 in JNCI: Journal of the National Cancer Institute
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Journal Article
Open access
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MJMarthe M de Jonge
Marthe M de Jonge
CKCor de Kroon
Cor de Kroon
DJDenise J Jenner
Denise J Jenner
JOJan Oosting
Jan Oosting
JHJoanne A de Hullu
Joanne A de Hullu
CAChristi J van Asperen
Christi J van Asperen
Endometrial cancer (EC) risk in BReast CAncer gene 1/2 (BRCA1/2) mutation carriers is uncertain; therefore, we assessed this in a large Dutch nationwide cohort study. We selected 5980 BRCA1/2 (3788 BRCA1, 2151 gBRCA2, 41 both BRCA1/BRCA2) and 8451 non-BRCA1/2 mutation carriers from the Hereditary Breast and Ovarian cancer study, the Netherlands cohort. Follow-up started at the date of the nationwide Dutch Pathology Registry coverage (January 1, 1989) or at the age of 25 years (whichever came last) and ended at date of EC diagnosis, last follow-up, or death (whichever came first). EC risk in BRCA1/2 mutation carriers was compared with 1) the general population, estimating standardized incidence ratios (SIRs) based on Dutch population-based incidence rates; and 2) non-BRCA1/2 mutation carriers, using Cox-regression analyses, expressed as hazard ratio (HR). Statistical tests were 2-sided. Fifty-eight BRCA1/2 and 33 non-BRCA1/2 mutation carriers developed EC over 119 296 and 160 841 person-years, respectively (SIR = 2.83, 95% confidence interval [CI] = 2.18 to 3.65; and HR = 2.37, 95% CI = 1.53 to 3.69, respectively). gBRCA1 mutation carriers showed increased risks for EC overall (SIR = 3.51, 95% CI = 2.61 to 4.72; HR = 2.91, 95% CI = 1.83 to 4.66), serous-like EC (SIR = 12.64, 95% CI = 7.62 to 20.96; HR = 10.48, 95% CI = 2.95 to 37.20), endometrioid EC (SIR = 2.63, 95% CI = 1.80 to 3.83; HR = 2.01, 95% CI = 1.18 to 3.45), and TP53-mutated EC (HR = 15.71, 95% CI = 4.62 to 53.40). For BRCA2 mutation carriers, overall (SIR = 1.70, 95% CI = 1.01 to 2.87) and serous-like EC risks (SIR = 5.11, 95% CI = 1.92 to 13.63) were increased compared with the general population. Absolute risks by 75 years remained low (overall EC = 3.0%; serous-like EC = 1.1%). BRCA1/2 mutation carriers have a two- to threefold increased risk for EC, with highest risk observed for the rare subgroups of serous-like and p53-abnormal EC in BRCA1 mutation carriers.

31 March 2015 in Molecular Cancer
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Journal Article
Open access
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SPSimone Punt
Simone Punt
JHJeanine J Houwing-Duistermaat
Jeanine J Houwing-Duistermaat
ISIris A Schulkens
Iris A Schulkens
VTVictor Thijssen
Victor Thijssen
EOElisabeth M Osse
Elisabeth M Osse
Ekaterina S. JordanovaEkaterina S. Jordanova
Ekaterina S. Jordanova
The 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. The 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. We 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). ‘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.


15 June 2021 in Cancers
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Journal Article
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Lise van WijkLise van Wijk
Lise van Wijk
CKClaire Kramer
Claire Kramer
SVSylvia Vermeulen
Sylvia Vermeulen
NHNatalja T. ter Haar
Natalja T. ter Haar
MJMarthe M. de Jonge
Marthe M. de Jonge
MVMaaike P. G. Vreeswijk
Maaike P. G. Vreeswijk
PARP inhibitor (PARPi) sensitivity is related to tumor-specific defects in homologous recombination (HR). Therefore, there is great clinical interest in tests that can rapidly and reliably identify HR deficiency (HRD). Functional HRD tests determine the actual HR status by using the (dis)ability to accumulate RAD51 protein at sites of DNA damage as read-out. In this study, we further improved and calibrated a previously described RAD51-based functional HRD test on 74 diagnostic formalin-fixed paraffin-embedded (FFPE) specimens (RAD51-FFPE test) from endometrial cancer (EC n = 25) and epithelial ovarian cancer (OC n = 49) patients. We established optimal parameters with regard to RAD51 foci cut-off (≥2) and HRD threshold (15%) using matched endometrial and ovarian carcinoma specimens for which HR status had been established using a RAD51-based test that required ex vivo irradiation of fresh tissue (RECAP test). The RAD51-FFPE test detected BRCA deficient tumors with 90% sensitivity and RECAP-HRD tumors with 87% sensitivity, indicating that it is an attractive alternative to DNA-based tests with the potential to be applied in routine diagnostic pathology.

10 January 2025 in Journal of Clinical Oncology
Verified
Journal Article
Open access
SFSarah E. Ferguson
Sarah E. Ferguson
LBLori A. Brotto
Lori A. Brotto
JKJanice Kwon
Janice Kwon
VSVanessa Samouelian
Vanessa Samouelian
GFGwenael Ferron
Gwenael Ferron
MPMArie Plante
MArie Plante
PURPOSE: Simple hysterectomy and pelvic node assessment (SHAPE) is a phase III randomized trial (ClinicalTrials.gov identifier: NCT01658930 ) reporting noninferiority of simple compared with radical hysterectomy for oncologic outcomes in low-risk cervical cancer. This study presents secondary outcomes of sexual health and quality of life (QOL) of the SHAPE trial. METHODS: Participants were randomly assigned to receive either radical or simple hysterectomy. Sexual health was assessed up to 36 months postoperatively using the Female Sexual Function Index (FSFI) and Female Sexual Distress Scale-Revised and QOL using European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and Cervical Cancer-Specific Module (QLQ-CX24) questionnaires. RESULTS: Among participants with at least one QOL measure, clinical and pathologic characteristics were balanced and with no differences in preoperative baseline scores for sexual health or QOL between groups. FSFI total score met the cutoff for dysfunction up to 6 months ( P = .02) in the radical hysterectomy group. Group differences favored simple hysterectomy for FSFI subscales: desire and arousal at 3 months ( P ≤ .001) and pain and lubrication up to 12 months ( P ≤ .018). Both groups met the cutoff for sexual distress but was higher in radical hysterectomy at 3 months ( P = .018). For QLQ-CX24, symptom experience was significantly better up to 24 months ( P = .031) and body image better at 3, 24, and 36 months ( P ≤ .01) for simple hysterectomy. Sexual-vaginal functioning was significantly better up to 24 months ( P ≤ .022) and more sexual activity up to 36 months ( P = .024) in the simple hysterectomy arm. Global health status was significantly higher at 36 months for simple hysterectomy ( P = .025). CONCLUSION: Simple hysterectomy was associated with lower rates of sexual dysfunction than radical hysterectomy, with a lower proportion of women having sustained sexual-vaginal dysfunction. These results further support the benefit of surgical de-escalation for low-risk cervical cancer.