EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT

Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is needed, but the conduct of epidemiological studies of paediatric CT populations poses a number of challenges which, if not addressed, could invalidate the results. The aim of the present paper is to review the main challenges of a study on the health impact of paediatric CTs and how the protocol of the European collaborative study EPI-CT, coordinated by the International Agency for Research on Cancer (IARC), is designed to address them. The study, based on a common protocol, is being conducted in Belgium, Denmark, France, Germany, the Netherlands, Norway, Spain, Sweden and the United Kingdom and it has recruited over one million patients suitable for long-term prospective follow-up. Cohort accrual relies on records of participating hospital radiology departments. Basic demographic information and technical data on the CT procedure needed to estimate organ doses are being abstracted and passive follow-up is being conducted by linkage to population-based cancer and mortality registries. The main issues which may affect the validity of study results include missing doses from other radiological procedures, missing CTs, confounding by CT indication and socioeconomic status and dose reconstruction. Sub-studies are underway to evaluate their potential impact. By focusing on the issues which challenge the validity of risk estimates from CT exposures, EPI-CT will be able to address limitations of previous CT studies, thus providing reliable estimates of risk of solid tumours and leukaemia from paediatric CT exposures and scientific bases for the optimisation of paediatric CT protocols and patient protection

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Dose estimation for the european epidemiological study on pediatric computed tomography (EPI-CT)

International audienceWithin the European Epidemiological Study to Quantify Risks for Paediatric Computerized Tomography (EPI-CT study), a cohort was assembled comprising nearly one million children, adolescents and young adults who received over 1.4 million computed tomography (CT) examinations before 22 years of age in nine European countries from the late 1970s to 2014. Here we describe the methods used for, and the results of, organ dose estimations from CT scanning for the EPI-CT cohort members. Data on CT machine settings were obtained from national surveys, questionnaire data, and the Digital Imaging and Communications in Medicine (DICOM) headers of 437,249 individual CT scans. Exposure characteristics were reconstructed for patients within specific age groups who received scans of the same body region, based on categories of machines with common technology used over the time period in each of the 276 participating hospitals. A carefully designed method for assessing uncertainty combined with the National Cancer Institute Dosimetry System for CT (NCICT, a CT organ dose calculator), was employed to estimate absorbed dose to individual organs for each CT scan received. The two-dimensional Monte Carlo sampling method, which maintains a separation of shared and unshared error, allowed us to characterize uncertainty both on individual doses as well as for the entire cohort dose distribution. Provided here are summaries of estimated doses from CT imaging per scan and per examination, as well as the overall distribution of estimated doses in the cohort. Doses are provided for five selected tissues (active bone marrow, brain, eye lens, thyroid and female breasts), by body region (i.e., head, chest, abdomen/pelvis), patient age, and time period (1977-1990, 1991-2000, 2001-2014). Relatively high doses were received by the brain from head CTs in the early 1990s, with individual mean doses (mean of 200 simulated values) of up to 66 mGy per scan. Optimization strategies implemented since the late 1990s have resulted in an overall decrease in doses over time, especially at young ages. In chest CTs, active bone marrow doses dropped from over 15 mGy prior to 1991 to approximately 5 mGy per scan after 2001. Our findings illustrate patterns of age-specific doses and their temporal changes, and provide suitable dose estimates for radiation-induced risk estimation in epidemiological studies

Fertility status among long-term childhood acute lymphoblastic leukaemia survivors enrolled between 1971 and 1998 in EORTC CLG studies: results of the 58 Late Adverse Effects study.

peer reviewedSTUDY QUESTION: What are the fertility outcomes of male and female childhood acute lymphoblastic leukaemia (ALL) long-term survivors? SUMMARY ANSWER: We observed similar fertility outcomes in both male and female childhood ALL survivors compared with the general population, with the exception of a higher proportion of miscarriages among partners of male survivors. WHAT IS KNOWN ALREADY: Survival after childhood ALL is currently >90% and fertility impairments are among the main concerns of the long-term survivors. Few studies have focused on the fertility issues within this selected population and the existing data are difficult to interpret due to the different treatment regimens received by the patients, the small sample sizes and the unavailability of control data in many studies. STUDY DESIGN, SIZE, DURATION: Childhood ALL patients enrolled in European Organisation for Research and Treatment of Cancer (EORTC) studies between 1971 and 1998 in France and Belgium, <18 years old at diagnosis and alive and ≥18 years at follow-up were eligible. Among 1418 eligible survivors, 507 (35.8%) participated (277 females, 230 males). Controls from the general population matched one to one by age, province, level of urbanization and sex could be identified for 503 survivors. PARTICIPANTS/MATERIALS, SETTING, METHODS: Survivors and controls were invited to fill out a questionnaire including information about their menstrual cycles (for females), intention to have children, having children, use of medical help to become pregnant and occurrence of negative pregnancy outcomes (birth defect, miscarriage, medical abortion or stillbirth). The results were analysed separately for females and males. The association between age at diagnosis and fertility outcomes, adjusted by age at follow-up, study and country were investigated using logistic regression. MAIN RESULTS AND THE ROLE OF CHANCE: The median time since diagnosis was 20.1 years and the median age at follow-up was 25 years. There were 144 survivors (97 females, 47 males) who wanted to have children. Among these, craniospinal radiotheraphy (CRT) and haematopoietic stem cell transplantation (HSCT) were administered to 18% and 4%, respectively. Of these who tried to have children, 75% of females and 69% of males succeeded, compared with 72% and 61% of the controls, respectively. These differences were not statistically significant (P = 0.73 for females and P = 0.50 for males). Overall, fertility outcomes were comparable between survivors and controls, except that a higher proportion of miscarriages occurred in partners of male survivors (28.1% versus 5.9%, P = 0.021). Among female survivors, an older age at diagnosis (10-17 years) was associated with a greater risk of pregnancy problems (adjusted OR 5.61, P = 0.046). LIMITATIONS, REASONS FOR CAUTION: The interpretation of the incidence of miscarriage among the partners of male survivors is limited by the lack of data regarding the males' partners and by a possibly higher tendency to recall and disclose fertility issues among male survivors compared with male controls. WIDER IMPLICATIONS OF THE FINDINGS: Fertility outcomes were similar in childhood ALL survivors and controls, and the low proportion of patients treated with CRT or HSCT might explain this. Further studies should confirm the higher proportion of miscarriages in partners of male survivors. STUDY FUNDING/COMPETING INTEREST(S): This publication was supported by donations from the Fonds Cancer (FOCA) from Belgium and the KU Leuven from Belgium. G.R. has been awarded a fellowship by the EORTC Cancer Research Fund (ECRF). C.P. has been awarded a fellowship by Fonds Cancer (FOCA) from Belgium and the Kinderkankerfonds from Belgium (a non-profit childhood cancer foundation under Belgian law). No competing interests were declared. TRIAL REGISTRATION NUMBER: NCT01298388 (clinicaltrials.gov)

Clinical significance of minimal residual disease in childhood acute lymphoblastic leukemia

Background and Methods: The implications of the detection of residual disease after treatment of acute lymphoblastic leukemia (ALL) are unclear. We conducted a prospective study at 11 centers to determine the predictive value of the presence or absence of detectable residual disease at several points in time during the first six months after complete remission of childhood ALL had been induced. Junctional sequences of T-cell-receptor or immunoglobulin gene rearrangements were used as clonal markers of leukemic cells. Residual disease was quantitated with a competitive polymerase-chain-reaction (PCR) assay. Of 246 patients enrolled at diagnosis and treated with a uniform chemotherapy protocol, 178 were monitored for residual disease with one clone-specific probe (in 74 percent) or more than one probe (in 26 percent). The median follow-up period was 38 months. Results: The presence or absence and level of residual leukemia were significantly correlated with the risk of early relapse at each of the times studied (P<0.001). PCR measurements identified patients at high risk for relapse after the completion of induction therapy (those with ≤10-2 residual blasts per 2x105 mononuclear bone marrow cells) or at later time points (those with ≤10-3 residual blasts). Multivariate analysis showed that as compared with immunophenotype, age, risk group (standard or very high risk), and white-cell count at diagnosis, the presence or absence and level of residual disease were the most powerful independent prognostic factors. Conclusions: Residual leukemia after induction of a remission is a powerful prognostic factor in childhood ALL. Detection of residual disease by PCR should be used to identify patients at risk for relapse and should be taken into account in considering alternative treatment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cohort Profile:the EPI-CT study: a European pooled epidemiological study to quantify the risk of radiation-induced cancer from paediatric CT

International audience•The multinational EPI-CT study was set-up in 2011 to provide direct estimates of risk of solid tumours and leukaemia among children and young adults who underwent computed tomography (CT) scanning and to consolidate the scientific basis for optimization of paediatric CT protocols and patient protection.•Under a common protocol, cohort studies were conducted in Belgium, Denmark, France, Germany, the Netherlands, Norway, Spain, Sweden and the United Kingdom, coordinated by the International Agency for Research on Cancer (IARC). •The study recruited a total of about 950,000 patients having undergone at least one CT-scan before the age of 22 years. A total of 8.7 million person-years of incidence follow-up were accrued between 1977 and 2014. Cohort members were followed up passively through linkage with population-based cancer and mortality registries. A methodology was developed to reconstruct individual organ doses and estimate associated uncertainties, using data available in electronic archiving systems of the radiology departments of participating hospitals. Description of the cohort and analysis of mortality risk are presented here.•Proposals for possible collaboration in further analyses of the data should be addressed to Dr. Ausrele Kesminiene ([email protected]) and will be reviewed by the EPI-CT steering committe

Long-term neurotoxicity among childhood acute lymphoblastic leukaemia survivors enrolled between 1971 and 1998 in EORTC Children Leukemia Group studies

Abstract Survival after childhood acute lymphoblastic leukemia (ALL) has increased over the last 40 years with an overall survival above 90%. Survivors may experience neurological late effects secondary to chemotherapy and radiotherapy. This observational retrospective study evaluated the cumulative incidence of neurological late effects among 890 childhood ALL survivors treated in EORTC CLG trials (58741, 58831/2 and 58881) between 1971 and 1998. Median follow-up was 19 years and interquartile range of the follow-up was 15–22 years. At 20 years from the end of treatment, approximately 66% of patients from the 58741 trial (accrual time: 1971–1978) and approximately 15% from the more recent trials had cognitive disturbance grade 1 or higher. Cumulative incidences at 20 years from treatment end of seizures, stroke and leukoencephalopathy were respectively 45%, 16% and 62% in study 58741, 13%, 2% and 5% in study 58831/2, and 8%, 2% and 3% in study 58881. Patients who were 10–17 years of age at diagnosis had a higher incidence of stroke and leukoencephalopathy as compared to those less than 6 years of age. Noteworthy, all neurological late effects continued to occur beyond 5 years after end of treatment. This retrospective study highlights the frequency of neurological late effects in survivors of childhood ALL. With the increase of the overall survival of ALL patients, the role and potential benefit of longitudinal neurological screening should be evaluated in further studies as these neurological late effects become an important public health challenge. This study is part of the larger EORTC CLG 58 Late Adverse Effects (LAE) study (ClinicalTrials.gov Identifier NCT01298388, date of registration February 16, 2011)

Socio-economic outcomes among long-term childhood acute lymphoblastic leukaemia survivors enrolled between 1971 and 1998 in EORTC CLG studies: Results of the 58LAE study.

peer reviewed("[en] OBJECTIVE: The objective of this study is to evaluate the socio-economic outcomes of survivors of childhood acute lymphoblastic leukaemia (ALL). METHODS: Childhood ALL adult survivors, enrolled in EORTC trials between 1971 and 1998 in France and Belgium, were invited to fill out a questionnaire with information about their socio-economic situation (living with a partner, having a university degree, having a job, working part time and history of having a paid job). The outcomes were compared with two matched control populations. RESULTS: Among 1418 eligible patients, 507 (35.8%) participated, including 39 (8%) and 61 (12%) patients who received a haematopoietic stem cell transplantation (HSCT) and a cranial radiotherapy (CRT), respectively. The median time to follow-up was 20 years, and median age was 25 years. Survivors showed a socio-economic level at least as good as controls. HCST and CRT were associated with a higher probability of not obtaining a bachelor degree (respectively OR = 3.49, 95% CI: 1.46-8.35 and OR = 2.31, 95% CI: 1.04-5.15), HSCT was associated with unemployment (OR = 2.89, 95% CI: 1.09-7.65) and having a relapse was associated with a higher probability of not having a partner (OR = 1.88, 95% CI: 1.01-3.51) adjusting for confounders. CONCLUSION: Childhood ALL survivors showed a high level of socio-economic participation. HCST and CRT were associated with poorer functioning.","[en] ",""