Ronald Zweemer

Prof. Ronald Zweemer

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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19 August 2015 in BMC Cancer
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MHMarline G. Harmsen
Marline G. Harmsen
MJMarieke Arts-De Jong
Marieke Arts-De Jong
NHNicoline Hoogerbrugge
Nicoline Hoogerbrugge
AMAngela H. E. M. Maas
Angela H. E. M. Maas
JPJudith B. Prins
Judith B. Prins
JHJoanne A. de Hullu
Joanne A. de Hullu
Risk-reducing salpingo-oophorectomy (RRSO) around the age of 40 is currently recommended to BRCA1/2 mutation carriers. This procedure decreases the elevated ovarian cancer risk by 80–96 % but it initiates premature menopause as well. The latter is associated with short-term and long-term morbidity, potentially affecting quality of life (QoL). Based on recent insights into the Fallopian tube as possible site of origin of serous ovarian carcinomas, an alternative preventive strategy has been put forward: early risk-reducing salpingectomy (RRS) and delayed oophorectomy (RRO). However, efficacy and safety of this alternative strategy have to be investigated. A multicentre non-randomised trial in 11 Dutch centres for hereditary cancer will be conducted. Eligible patients are premenopausal BRCA1/2 mutation carriers after completing childbearing without (a history of) ovarian carcinoma. Participants choose between standard RRSO at age 35–40 (BRCA1) or 40–45 (BRCA2) and the alternative strategy (RRS upon completion of childbearing and RRO at age 40–45 (BRCA1) or 45–50 (BRCA2)). Women who opt for RRS but do not want to postpone RRO beyond the currently recommended age are included as well. Primary outcome measure is menopause-related QoL. Secondary outcome measures are ovarian/breast cancer incidence, surgery-related morbidity, histopathology, cardiovascular risk factors and diseases, and cost-effectiveness. Mixed model data analysis will be performed. The exact role of the Fallopian tube in ovarian carcinogenesis is still unclear. It is not expected that further fundamental research will elucidate this role in the near future. Therefore, this clinical trial is essential to investigate RRS with delayed RRO as alternative risk-reducing strategy in order to improve QoL. ClinicalTrials.gov ( NCT02321228 )

19 February 2022 in Cancers
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KBKyra Bokkers
Kyra Bokkers
MVMichiel Vlaming
Michiel Vlaming
EEEllen G. Engelhardt
Ellen G. Engelhardt
RZRonald Zweemer
Ronald Zweemer
IOInge M. van Oort
Inge M. van Oort
MAMargreet Center Ausems
Margreet Center Ausems
Background: Non-genetic healthcare professionals can provide pre-test counseling and order germline genetic tests themselves, which is called mainstream genetic testing. In this systematic review, we determined whether mainstream genetic testing was feasible in daily practice while maintaining quality of genetic care. Methods: PubMed, Embase, CINAHL, and PsychINFO were searched for articles describing mainstream genetic testing initiatives in cancer care. Results: Seventeen articles, reporting on 15 studies, met the inclusion criteria. Non-genetic healthcare professionals concluded that mainstream genetic testing was possible within the timeframe of a routine consultation. In 14 studies, non-genetic healthcare professionals completed some form of training about genetics. When referral was coordinated by a genetics team, the majority of patients carrying a pathogenic variant were seen for post-test counseling by genetic healthcare professionals. The number of days between cancer diagnosis and test result disclosure was always lower in the mainstream genetic testing pathway than in the standard genetic testing pathway (e.g., pre-test counseling at genetics department). Conclusions: Mainstream genetic testing seems feasible in daily practice with no insurmountable barriers. A structured pathway with a training procedure is desirable, as well as a close collaboration between genetics and other clinical departments.

21 May 2020 in Cancers
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JRJoline Roze
Joline Roze
GMGlen Monroe
Glen Monroe
JKJoachim Kutzera
Joachim Kutzera
JGJolijn Groeneweg
Jolijn Groeneweg
ESEllen Stelloo
Ellen Stelloo
RZRonald Zweemer
Ronald Zweemer
Adult granulosa cell tumors (AGCTs) harbor a somatic FOXL2 c.402C>G mutation in ~95% of cases and are mainly surgically removed due to limited systemic treatment effect. In this study, potentially targetable genomic alterations in AGCTs were investigated by whole genome sequencing on 46 tumor samples and matched normal DNA. Copy number variant (CNV) analysis confirmed gain of chromosome 12 and 14, and loss of 22. Pathogenic TP53 mutations were identified in three patients with highest tumor mutational burden and mitotic activity, defining a high-grade AGCT subgroup. Within-patient tumor comparisons showed 29–80% unique somatic mutations per sample, suggesting tumor heterogeneity. A higher mutational burden was found in recurrent tumors, as compared to primary AGCTs. FOXL2-wildtype AGCTs harbored DICER1, TERT(C228T) and TP53 mutations and similar CNV profiles as FOXL2-mutant tumors. Our study confirms that absence of the FOXL2 c.402C>G mutation does not exclude AGCT diagnosis. The lack of overlapping variants in targetable cancer genes indicates the need for personalized treatment for AGCT patients.

26 July 2023 in Cancers
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FWFrancis Simone, Petronella, Louisa Wens
Francis Simone, Petronella, Louisa Wens
CHCaroline Hulsker
Caroline Hulsker
MFMarta Fiocco
Marta Fiocco
JZJózsef Zsiros
József Zsiros
SSStephanie E. Smetsers
Stephanie E. Smetsers
AMAnnelies M.C. Mavinkurve-Groothuis
Annelies M.C. Mavinkurve-Groothuis
Background: Small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare aggressive ovarian malignancy mainly affecting children, adolescents, and young adults. Since the discovery of mutations in the SMARCA4 gene in 2014, SCCOHT has become the subject of extensive investigation. However, international uniform treatment guidelines for SCCOHT are lacking and the outcome remains poor. The aim of this systematic review is to generate an overview of all reported patients with SCCOHT from 1990 onwards, describing the clinical presentation, genetic characteristics, treatment, and outcome. Methods: A systematic search was performed in the databases Embase, Medline, Web of Science, and Cochrane for studies that focus on SCCOHT. Patient characteristics and treatment data were extracted from the included studies. Survival was estimated using Kaplan–Meier’s methodology. To assess the difference between survival, the log-rank test was used. To quantify the effect of the FIGO stage, the Cox proportional hazard regression model was estimated. The chi-squared test was used to study the association between the FIGO stage and the surgical procedures. Results: Sixty-seven studies describing a total of 306 patients were included. The median patient age was 25 years (range 1–60 years). The patients mostly presented with non-specific symptoms such as abdominal pain and sometimes showed hypercalcemia and elevated CA-125. A great diversity in the diagnostic work-up and therapeutic approaches was reported. The chemotherapy regimens were very diverse, all containing a platinum-based (cisplatin or carboplatin) backbone. Survival was strongly associated with the FIGO stage at diagnosis. Conclusions: SCCOHT is a rare and aggressive ovarian cancer, with a poor prognosis, and information on adequate treatment for this cancer is lacking. The testing of mutations in SMARCA4 is crucial for an accurate diagnosis and may lead to new treatment options. Harmonization and international collaboration to obtain high-quality data on diagnostic investigations, treatment, and outcome are warranted to be able to develop international treatment guidelines to improve the survival chances of young women with SCCOHT.

17 June 2022 in Cancers
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ABAnna Brink
Anna Brink
JGJolijn Groeneweg
Jolijn Groeneweg
LHLotty Hooft
Lotty Hooft
RZRonald Zweemer
Ronald Zweemer
PWPetronella O. Witteveen
Petronella O. Witteveen
For adult granulosa cell tumors (aGCTs), the preferred treatment modality is surgery. Chemotherapy and anti-hormonal therapy are also frequently used in patients with recurrent aGCT. We aimed to review the existing literature on the response to chemotherapy and anti-hormonal therapy in patients with aGCT. Embase and MEDLINE were searched from inception to November 2021 for eligible studies. Objective response rate (ORR) was calculated as the total number of cases with a complete response (CR) or a partial response (PR). Disease control rate (DCR) was defined as the sum of cases with CR, PR or stable disease (SD). A total of 10 studies were included that reported on chemotherapy and 13 studies were included that reported on anti-hormonal therapy. The response rates of the 56 chemotherapy regimens that could be evaluated resulted in an ORR of 30% and DCR of 58%. For anti-hormonal therapy, the results of 73 regimens led to an ORR of 11% and a DCR of 66%. Evidence on systemic therapy in aGCT only is limited. For both chemotherapy and anti-hormonal therapy, the ORR is limited, but the response is considerably higher when patients achieving SD are included. New approaches are needed to provide more evidence and standardize treatment in aGCT.

1 December 2006 in Journal of Clinical Pathology
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Journal Article
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PVP M L H Vencken
P M L H Vencken
PEP C Ewing
P C Ewing
RZRonald Zweemer
Ronald Zweemer
Epithelioid trophoblastic tumour (ETT) is an unusual type of trophoblastic tumour, which can cause difficulties in diagnosis and (as a consequence) in treatment. The literature suggests that surgery should be the treatment of choice for ETT as it is not responsive to chemotherapeutic agents, used in the treatment of other types of gestational trophoblastic diseases. This case report describes an ETT, which was initially diagnosed as a carcinoma of the cervix. Surgical management was chosen based on the literature. 6 months later the patient also developed a plasmacytoma and was treated with radiotherapy. The occurrence of ETT and plasmacytoma in combination has never been described before. This case report describes a rare case of an atypical trophoblastic tumour, with problematic differential diagnosis. Treatment of carcinoma of the cervix would have necessitated postoperative radiotherapy, but on diagnosis of ETT, surgical management was considered sufficient. Hence, it is important to consider the occurrence of ETTs, although rare, in patients with atypical cervical or endometrial cancer, and in patients diagnosed with a gestational trophoblastic tumour, who do not respond to appropriate chemotherapy.