Molecular determinants of juvenile myelomonosytic leukemia and childhood myelodysplastic syndrome

In the general population the probability of developing cancer before the age of 18 years is around 1 in 400. In the Netherlands, approximately 600 new children each year are diagnosed with cancer (Figure 1). The most common types of childhood cancer are leukemias and the distribution of cancer types varies with age. Figure 2 gives an overview of the incidence of the different subclasses of leukemia as registered by the DCOG (2005-2010). Acute lymphoblastic leukemia (ALL) accounts for about 80% of the leukemias, whereas acute myeloid leukemia (AML) accounts for about 15% of all leukemias. Myelodysplastic syndrome (MDS) and Juvenile Myelomonocytic Leukemia (JMML), which are the subject of this thesis, represent very rare myeloid malignancies in childhood. Over the last decades, following better treatment stratification, better chemotherapy combinations and improved supportive care regimens, the 5-year survival of cancer in children and adolescents improved significantly (Figure 3). The survival of MDS and JMML however, has reached a plateau at approximately 50% following stem cell transplantation, which is the only curative treatment option for these diseases

A comparison of the Muenster, SIOP Boston, Brock, Chang and CTCAEv4.03 ototoxicity grading scales applied to 3,799 audiograms of childhood cancer patients treated with platinum-based chemotherapy

Childhood cancer patients treated with platinums often develop hearing loss and the degree is classified accord

TIMELESS Forms a Complex with PARP1 Distinct from Its Complex with TIPIN and Plays a Role in the DNA Damage Response

SummaryPARP1 is the main sensor of single- and double-strand breaks in DNA and, in building chains of poly(ADP-ribose), promotes the recruitment of many downstream signaling and effector proteins involved in the DNA damage response (DDR). We show a robust physical interaction between PARP1 and the replication fork protein TIMELESS, distinct from the known TIMELESS-TIPIN complex, which activates the intra-S phase checkpoint. TIMELESS recruitment to laser-induced sites of DNA damage is dependent on its binding to PARP1, but not PARP1 activity. We also find that the PARP1-TIMELESS complex contains a number of established PARP1 substrates, and TIMELESS mutants unable to bind PARP1 are impaired in their ability to bind PARP1 substrates. Further, PARP1 binding to certain substrates and their recruitment to DNA damage lesions is impaired by TIMELESS knockdown, and TIMELESS silencing significantly impairs DNA double-strand break repair. We hypothesize that TIMELESS cooperates in the PARP1-mediated DDR

Psychosocial functioning of adult siblings of Dutch very long-term survivors of childhood cancer: DCCSS-LATER 2 psycho-oncology study

ObjectiveTo describe psychosocial outcomes among adult siblings of very long-term childhood cancer survivors (CCS), to compare these outcomes to reference populations and to identify factors associated with siblings' psychosocial outcomes. MethodsSiblings of survivors (diagnosed 5 years since diagnosis) of the Dutch Childhood Cancer Survivor Study DCCSS-LATER cohort were invited to complete questionnaires on HRQoL (TNO-AZL Questionnaire for Adult's HRQoL), anxiety/depression (Hospital Anxiety and Depression Scale), post-traumatic stress (Self-Rating Scale for Post-traumatic Stress Disorder), self-esteem (Rosenberg Self-Esteem Scale) and benefit and burden (Benefit and Burden Scale for Children). Outcomes were compared to a reference group if available, using Mann-Whitney U and chi-Square tests. Associations of siblings' sociodemographic and CCS' cancer-related characteristics with the outcomes were assessed with mixed model analysis. ResultsFive hundred five siblings (response rate 34%, 64% female, mean age 37.5, mean time since diagnosis 29.5) of 412 CCS participated. Siblings had comparable HRQoL, anxiety and self-esteem to references with no or small differences (r = 0.08-0.15, p < 0.05) and less depression. Proportions of symptomatic PTSD were very small (0.4%-0.6%). Effect sizes of associations of siblings' sociodemographic and CCS cancer-related characteristics were mostly small to medium (& beta; = 0.19-0.67, p < 0.05) and no clear trend was found in the studied associated factors for worse outcomes. ConclusionsOn the very long-term, siblings do not have impaired psychosocial functioning compared to references. Cancer-related factors seem not to impact siblings' psychosocial functioning. Early support and education remain essential to prevent long-term consequences.Metabolic health: pathophysiological trajectories and therap

Echocardiography protocol for early detection of cardiac dysfunction in childhood cancer survivors in the multicenter DCCSS LATER 2 CARD study: design, feasibility, and reproducibility

Background Cardiotoxicity is a well-known side effect after anthracyclines and chest radiotherapy in childhood cancer survivors (CCS). The DCCSS LATER 2 CARD (cardiology) study includes evaluation of echocardiographic measurements for early identification of CCS at highest risk of developing heart failure. This paper describes the design, feasibility, and reproducibility of the echocardiography protocol.Methods Echocardiograms from CCS and sibling controls were prospectively obtained at the participating centers and centrally analyzed. We describe the image acquisition, measurement protocol, and software-specific considerations for myocardial strain analyses. We report the feasibility of the primary outcomes of systolic and diastolic function, as well as reproducibility analyses in 30 subjects.Results We obtained 1,679 echocardiograms. Biplane ejection fraction (LVEF) measurement was feasible in 91% and 96% of CCS and siblings, respectively, global longitudinal strain (GLS) in 80% and 91%, global circumferential strain (GCS) in 86% and 89%, and >= 2 diastolic function parameters in 99% and 100%, right ventricle free wall strain (RVFWS) in 57% and 65%, and left atrial reservoir strain (LASr) in 72% and 79%. Intra-class correlation coefficients for inter-observer variability were 0.85 for LVEF, 0.76 for GLS, 0.70 for GCS, 0.89 for RVFWS and 0.89 for LASr. Intra-class correlation coefficients for intra-observer variability were 0.87 for LVEF, 0.82 for GLS, 0.82 for GCS, 0.85 for RVFWS and 0.79 for LASr.Conclusion The DCCSS LATER 2 CARD study includes a protocolized echocardiogram, with feasible and reproducible primary outcome measurements. This ensures high-quality outcome data for prevalence estimates and for reliable comparison of cardiac function parameters.Diabetes mellitus: pathophysiological changes and therap

Methodology of the DCCSS later fatigue study: a model to investigate chronic fatigue in long-term survivors of childhood cancer

Background A debilitating late effect for childhood cancer survivors (CCS) is cancer-related fatigue (CRF). Little is known about the prevalence and risk factors of fatigue in this population. Here we describe the methodology of the Dutch Childhood Cancer Survivor Late Effect Study on fatigue (DCCSS LATER fatigue study). The aim of the DCCSS LATER fatigue study is to examine the prevalence of and factors associated with CRF, proposing a model which discerns predisposing, triggering, maintaining and moderating factors. Triggering factors are related to the cancer diagnosis and treatment during childhood and are thought to trigger fatigue symptoms. Maintaining factors are daily life- and psychosocial factors which may perpetuate fatigue once triggered. Moderating factors might influence the way fatigue symptoms express in individuals. Predisposing factors already existed before the diagnosis, such as genetic factors, and are thought to increase the vulnerability to develop fatigue. Methodology of the participant inclusion, data collection and planned analyses of the DCCSS LATER fatigue study are presented. Results Data of 1955 CCS and 455 siblings was collected. Analysis of the data is planned and we aim to start reporting the first results in 2022. Conclusion The DCCSS LATER fatigue study will provide information on the epidemiology of CRF and investigate the role of a broad range of associated factors in CCS. Insight in associated factors for fatigue in survivors experiencing severe and persistent fatigue may help identify individuals at risk for developing CRF and may aid in the development of interventions.Diabetes mellitus: pathophysiological changes and therap

Positive and negative survivor-specific psychosocial consequences of childhood cancer: the DCCSS-LATER 2 psycho-oncology study

Purpose: Numerous studies investigated generic psychosocial outcomes in survivors of childhood cancer (CCS). The present study aimed to describe survivor-specific psychosocial consequences in CCS, and to identify socio-demographic and medical associated factors. Methods: CCS from the Dutch Childhood Cancer Survivor Study (DCCSS)-LATER cohort (diagnosed 1963-2001) part 2 (age >= 18 years, diagnosed = 5 years since diagnosis) completed the Benefit & Burden Scale (BBSC) and the Impact of Cancer-Childhood Cancer (IOC-CS). Items were scored on a 5-point Likert scale (range 1-5). We examined outcomes with descriptive statistics, and socio-demographic and medical associated factors with regression analyses, corrected for multiple testing (p = 15 years since diagnosis, participated. On average, CCS reported 'somewhat' Benefit (M = 2.9), and 'not at all' to 'a little' Burden (M = 1.5) of childhood cancer. Average scores on IOC-CS' positive impact scales ranged from 2.5 (Personal Growth) to 4.1 (Socializing), and on the negative impact scales from 1.4 (Financial Problems) to 2.4 (Thinking/Memory). Apart from cognitive problems, CCS reported challenges as worries about relationship status, fertility, and how cancer had affected siblings. Female sex was associated with more Personal Growth, and more negative impact. CCS more highly educated, partnered, and employed had higher positive and lower negative impact. CCS older at diagnosis reported more positive impact. CNS tumor survivors and those who had head/cranium radiotherapy had higher negative impact. CNS tumor survivors reported less positive impact. Conclusion and implications: The majority of CCS reported positive impact of cancer while most CCS reported little negative impact. While this may indicate resiliency in most CCS, health care providers should be aware that they can also experience survivor-specific challenges that warrant monitoring/screening, information provision and psychosocial support.Metabolic health: pathophysiological trajectories and therap