A study of pediatric brain tumors and their association with epilepsy and anticonvulsant use

Maternal and childhood medical history and the risk of childhood brain tumours: a case-control study in Ontario, Canada

BACKGROUND

Studies to date have yielded inconclusive results as to whether maternal medical history during pregnancy, and a child's early-life medical history contribute to the development of childhood brain tumours (CBTs). This study examined associations between maternal and childhood medical history and the risk of CBTs.

METHODS

The Childhood Brain Tumour Epidemiology Study of Ontario (CBREO) examined children 0-15 years of age with newly diagnosed CBTs from 1997 to 2003. Multivariable logistic regression analysis determined associations for prenatal medications and childhood medical history, adjusted for child's demographics, and maternal education. Analyses were stratified by histology. A latency period analysis was conducted using 12- and 24-month lead times.

RESULTS

Maternal intake of immunosuppressants during the prenatal period was significantly associated with glial tumours (OR 2.73, 95% CI 1.17-6.39). Childhood intake of anti-epileptics was significantly associated with CBTs overall, after accounting for 12-month (OR 8.51, 95% CI 3.35-21.63) and 24-month (OR 6.04, 95% CI 2.06-17.70) lead time before diagnosis. No associations for other medications were found.

CONCLUSIONS

This study underscores the need to examine potential carcinogenic effects of the medication classes highlighted and of the indication of medication use. Despite possible reverse causality, increased CBT surveillance for children with epilepsy might be warranted.

Danish Population Based Study of Familial Epilepsy and Childhood Cancer

Objective

Results from studies investigating the association between maternal or child epilepsy, use of anticonvulsants in pregnancy, and childhood cancer are inconsistent and at times contradictory.

Methods

Linking Danish national databases, we obtained epilepsy and childhood cancer diagnoses, and anticonvulsant use data. We estimated adjusted odds ratios of all or specific childhood cancers in relation to maternal or child epilepsy and anticonvulsant therapies using conditional logistic regression.

Results

Maternal epilepsy was positively associated with all childhood cancers in offspring, specifically, with acute lymphoblastic leukemia (Odds Ratio (OR) = 1.68, 95% Confidence Interval (CI) = 1.16, 2.43) and Wilms tumor (OR = 2.13, 95%CI = 0.97, 4.68). When considering maternal ever (lifetime) ingestion of anticonvulsants, a positive association was found with all cancers (OR = 1.15, 95%CI = 1.01, 1.31), and central nervous system tumors (OR = 1.32, 95%CI = 1.03, 1.69) as well as neuroblastoma (OR = 2.05, 95%CI = 1.29, 3.28) among offspring. Maternal anticonvulsant use before or during the index pregnancy was related to CNS tumors in offspring (OR = 1.78, 95%CI = 0.99, 3.21), however the confidence interval included the null.

Significance

Maternal use of certain anticonvulsant medications may be a risk factor for cancer in offspring. Medical providers may need to consider what type of treatments to prescribe to pregnant mothers with epilepsy.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer. We conducted a systematic search in the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to June 8, 2020. Altogether, 112 studies were identified. The reviewed studies were heterogeneous in study design, exposure, and outcome classification. In 21 studies (19%), the outcome was any childhood cancer. Of the 91 papers that reported on specific types of cancer, 62% did not report the cancer classification system. The most frequently investigated medication groups were sex hormones (46 studies, excluding fertility medications), and antiinfectives (37 studies). Suggestions for strengthening future pharmacoepidemiologic studies on maternal medication use and childhood cancer relate to choice of cancer classification system, exposure windows, and methods for identification of, and control for, potential confounders.

Advances in Epidemiological Methods and Utilisation of Large Databases: A Methodological Review of Observational Studies on Central Nervous System Drug Use in Pregnancy and Central Nervous System Outcomes in Children

INTRODUCTION

Studies have used various epidemiological approaches to study associations between central nervous system (CNS) drug use in pregnancy and CNS outcomes in children. Studies have generally focused on clinical adverse effects, whereas variations in methodologies have not received sufficient attention.

OBJECTIVE

Our objective was to review the methodological characteristics of existing studies to identify any limitations and recommend further research.

METHODS

A systematic literature search was conducted on observational studies listed in PubMed from 1 January 1946 to 21 September 2017. Following independent screening and data extraction, we conducted a review addressing the trends of relevant studies, differences between various data sources, and methods used to address bias and confounders; we also conducted statistical analyses.

RESULTS

In total, 111 observational studies, 25 case-control studies, and 86 cohort studies were included in the review. Publications dating from 1978 to 2006 mainly focused on antiepileptic drugs, but research on antidepressants increased from 2007 onwards. Only one study focused on antipsychotic use during pregnancy. A total of 46 studies obtained data from an administrative database/registry, 20 from ad hoc disease registries, and 41 from ad hoc clinical samples. Most studies (58%) adjusted the confounding factors using general adjustment, whereas only a few studies used advanced methods such as sibling-matched models and propensity score methods; 42 articles used univariate analyses and 69 conducted multivariable regression analyses.

CONCLUSION

Multiple factors, including different study designs and data sources, have led to inconsistent findings in associations between CNS drug use in pregnancy and CNS outcomes in children. Researchers should allow for study designs with clearly defined exposure periods, at the very least in trimesters, and use advanced confounding adjustment methodology to increase the accuracy of the findings.

Co-morbidities in people living with epilepsy: hospital based case-control study from a resource-poor setting

PURPOSE

Evaluating co-morbidity in people living with epilepsy (PWE) is essential and its modification might improve their quality of life. We analyzed the various co-morbidities in PWE in comparison with the normal healthy controls.

METHOD

This prospective study was conducted from July 2006 to December 2007. PWE attending neurology outpatient services (n=250) with age ranging from 16 to 60 years (29.66+/-11.31 years; M:F 116:134) were recruited after obtaining informed consent. Healthy matched controls (n=250; 30.35+/-11.05 years; M:F 114:136) were also recruited.

RESULTS

The seizure types were: generalized (62.4%), complex-partial (21.6%), simple-partial (8.8%), and unclassified (7.2%). Sixty-nine percent were on monotherapy, and rest required polytherapy, with 90.8% on adequate dosages of anti-convulsants. About 83.2% were compliant and 70.4% had satisfactory control of seizures. At least 1 co-morbid condition was noted in 152 (60.8%) cases and among them, 62 (24.8%) had > or =2 co-morbidities. Control population was also evaluated for the presence of same co-morbidities and compared with cases. The various significant co-morbidities included: migraine (cases: 25.6% vs. controls: 15.2%; p=0.02), anxiety (cases: 2.4% vs. controls: 0%; p=0.04), depression (case: 5.2% vs. controls: 0.4%; p=0.0009), sleep disturbances (case: 6.8% vs. controls: 0.4%; p=0.0002), neurocysticercosis (cases: 15.6% vs. controls: 0%; p=<0.001), pulmonary tuberculosis (cases: 3.6% vs. controls: 0%; p=0.002) and extra-pulmonary tuberculosis (cases: 2.8% vs. controls: 0.4%; p=0.03). Less common co-morbidities were hypertension, diabetes, osteoarthritis, asthma, hypothyroidism, and acid-peptic disease.

CONCLUSION

In people living with epilepsy attending neurology OPD services, co-morbid illnesses were commonly observed compared to healthy controls.

Beauty product-related exposures and childhood brain tumors in seven countries: results from the SEARCH International Brain Tumor Study

Data from 1218 cases of childhood brain tumors (CBT) diagnosed between 1976 and 1994 and 2223 matched controls from the general population were included in an analysis of maternal beauty product exposure and beauty-related employment in 9 centers in 7 countries. A 50% increased odds ratio (OR) [95% confidence interval (CI) = 1.0-2.1] for CBT was observed among children of mothers who were exposed via personal use of and/or possible ambient contact with beauty products during the 5 years preceding the index child's birth compared with children of mothers never exposed to beauty products during this time period. Overall maternal personal use of hair-coloring agents in the month before or during the pregnancy of the index child's birth was not associated with CBT (OR = 1.0, CI = 0.83-1.3) or with astroglial (OR = 1.1, CI = 0.85-1.4), PNET (OR = 1.0, CI = 0.71-1.5) and other glial subtypes (OR = 1.0, CI = 0.62-1.0). Similarly, no statistically increased ORs or discernable pattern of risk estimates were observed for period of use or for number of applications per year for maternal personal use of hair-coloring agents overall or by histologic type. Among children born on or after 1980, increased ORs for CBT were associated with maternal non-work-related exposure to any beauty products (OR = 2.6, CI = 1.2-5.9), hair-dyes (OR = 11, CI = 1.2-90), and hair sprays (OR = 3.4, CI = 1.0-11). No overall increased OR for CBT was observed among children of mothers employed in beauty-related jobs during the 5 years preceding the index child's birth compared with those who reported no beauty-related employment. In general, other specific beauty product-related exposures were not associated with increased ORs for CBT. Data from our study provide little evidence of an increased risk for CBT with mothers' exposures to beauty products.

The Epidemiology of the Comorbidity of Epilepsy in the General Population

PURPOSE

To describe the epidemiology of somatic and psychiatric conditions in adults with epilepsy in the community and compare it to that of people without epilepsy.

METHODS

A cross-sectional population-based study extracting data from the UK General Practice Research Database for the period 1995-1998. Age- and sex-standardized prevalence rates were estimated for selected conditions and groups of conditions (categorized by ICD-9 chapters) in adults with epilepsy registered with primary care physicians. Results were compared with those in adults without epilepsy in the cohort, and prevalence ratios were calculated according to two broad age groups (16-64 and older than 64 years).

RESULTS

Conditions common in the general population also were common in adults with epilepsy. Psychiatric disorders occurred twice as often, and the risk of somatic disorders was increased in people with epilepsy, with the exception of musculoskeletal and connective tissue disorders in older adults. The prevalence ratio of neoplasia, excluding intracranial tumors, was not increased in epilepsy. The prevalence ratio of brain tumors was particularly increased in young adults [prevalence ratio (PR), 70.7] and of meningiomas in older adults (PR, 91.9). Neurodegenerative conditions, particularly dementias and Alzheimer' disease (PR, 6.3 and 8, respectively) and Parkinson' disease (PR, 3.2), appeared more frequently in people with epilepsy. Upper gastrointestinal bleed occurred more frequently in epilepsy (PR, 4.3), as did cardio- and cerebrovascular disorders, fractures, pneumonia and chronic lung diseases, and diabetes. Eczema, osteoarthritis, and rheumatoid arthritis did not occur more frequently in epilepsy.

CONCLUSIONS

The prevalence ratio of many common psychiatric and somatic conditions is increased in adults with epilepsy who consult a primary care physician in the U.K. These findings may have implications in the diagnosis and management of epilepsy and coexisting conditions, as well as in health care provision.

Epidemiology of brain tumors in childhood--a review

Malignant brain tumors are the leading cause of cancer death among children and the second most common type of pediatric cancer. Despite several decades of epidemiologic investigation, the etiology of childhood brain tumors (CBT) is still largely unknown. A few genetic syndromes and ionizing radiation are established risk factors. Many environmental exposures and infectious agents have been suspected of playing a role in the development of CBT. This review, based on a search of the medical literature through August 2003, summarizes the epidemiologic evidence to date. The types of exposures discussed include ionizing radiation, N-nitroso compounds (NOC), pesticides, tobacco smoke, electromagnetic frequencies (EMF), infectious agents, medications, and parental occupational exposures. We have chosen to focus on perinatal exposures and review some of the recent evidence indicating that such exposures may play a significant role in the causation of CBT. The scientific community is rapidly learning more about the molecular mechanisms by which carcinogenesis occurs and how the brain develops. We believe that advances in genetic and molecular biologic technology, including improved histologic subtyping of tumors, will be of huge importance in the future of epidemiologic research and will lead to a more comprehensive understanding of CBT etiology. We discuss some of the early findings using these technologies.

Risk factors for pediatric tumors of the central nervous system: results from a German population-based case-control study

BACKGROUND

From 1993 to 1997 we conducted two population-based case-control studies on childhood cancer and a variety of potential risk factors in Germany. One case group involved children under the age of 15 years having a tumor of the central nervous system (CNS).

PROCEDURE

For both studies, one conducted in the northwestern area of Germany, the other covering the whole of West Germany, incident cases were identified from the nationwide German Childhood Cancer Registry, and controls were randomly selected from complete population registration files.

RESULTS

In total 466 pediatric CNS tumor cases and 2,458 controls were available for analyses. We observed only few positive associations, namely, between CNS tumors and low birth weight [<2,500 g; odds ratio (OR), 1.73; 95% confidence interval (CI), 1.06-2.84], between ependymoma and maternal smoking during pregnancy (>10 cigarettes per day: OR, 4.71; 95% CI, 1.69-13.1), and between astrocytoma and exposure to wood preservatives (OR, 1.91; 95% CI, 1.22-3.01). CNS tumors were not associated with high birth weight, duration of breast feeding, maternal age at time of delivery, duration of gestation, previous fetal losses, paternal smoking during pregnancy, maternal alcohol consumption, the child's exposure to pesticides, maternal diagnostic X-ray examinations during pregnancy, X-ray examinations of the child, or exposure to residential magnetic fields.

CONCLUSIONS

Despite the large study population, we found only few factors that were associated with CNS tumors or one of the morphological subgroups. Therefore, our results suggest that aspects of the prenatal and neonatal period play only a minor role in the etiology of pediatric CNS tumors.

Role of medical history in brain tumour development. Results from the international adult brain tumour study

In an international population-based case-control study carried out in 8 centres in 6 countries, we investigated the role of specific medical conditions in the aetiology of brain tumours in adults. Recruited were 1,178 glioma and 331 meningioma cases and 2,493 age- and gender-matched population controls. Only medical conditions occurring at least 2 years before brain tumour diagnosis were considered. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using a conditional logistic regression model. Heterogeneity between centres was tested. No association between meningioma and previous medical conditions was observed. For glioma, there was an increased risk associated with epilepsy (RR = 6.55, 95% CI 3.40-12.63), but this was considerably weaker for epilepsy of more than 20 years duration. The risk remained elevated after adjustment for use of anti-epileptic drugs. There was a statistically significant inverse association between glioma and all allergic diseases combined (RR = 0.59, 95% CI 0.49-0.71); this was also observed for specific allergic conditions, namely, asthma and eczema. Subjects who reported a history of infectious diseases (e.g., colds, flu) showed a 30% reduction in risk (RR = 0.72, 95% CI 0.61-0.85). The decreased risks for glioma in subjects reporting a history of allergic conditions or infectious diseases may indicate an influence of immunological factors on the development of glioma. The association between glioma and epilepsy has to be interpreted cautiously and needs further investigation.