Nonchromosomal birth defects and risk of childhood acute leukemia: An assessment in 15 000 leukemia cases and 46 000 controls from the Childhood Cancer and Leukemia International Consortium.

Although recent studies have demonstrated associations between nonchromosomal birth defects and several pediatric cancers, less is known about their role on childhood leukemia susceptibility. Using data from the Childhood Cancer and Leukemia International Consortium, we evaluated associations between nonchromosomal birth defects and childhood leukemia. Pooling consortium data from 18 questionnaire-based and three registry-based case-control studies across 13 countries, we used multivariable logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between a spectrum of birth defects and leukemia.

Breastfeeding and risk of childhood brain tumors: a report from the Childhood Cancer and Leukemia International Consortium.

Purpose: Studies report mixed findings regarding the association of breastfeeding with childhood brain tumors (CBT), the leading causes of cancer-related mortality in young people. Our objective was to determine whether breastfeeding is associated with CBT incidence.

Methods: We pooled data on N = 2610 cases with CBT (including 697 cases with astrocytoma, 447 cases with medulloblastoma/primitive neuroectodermal tumor [PNET], 167 cases with ependymoma) and N = 8128 age- and sex-matched controls in the Childhood Cancer and Leukemia International Consortium.

Infant feeding practices and childhood acute leukemia: Findings from the Childhood Cancer & Leukemia International Consortium.

Increasing evidence suggests that breastfeeding may protect from childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). However, most studies have limited their analyses to any breastfeeding, and only a few data have examined exclusive breastfeeding, or other exposures such as formula milk. We performed pooled analyses and individual participant data metaanalyses of data from 16 studies (N = 17 189 controls; N = 10 782 ALL and N = 1690 AML cases) from the Childhood Leukemia International Consortium (CLIC) to characterize the associations of breastfeeding duration with ALL and AML, as well as exclusive breastfeeding duration and age at introduction to formula with ALL.

Bias factor, maximum bias and the E-value: insight and extended applications.

Background: Unmeasured confounding can bias the relationship between exposure and outcome. Sensitivity analyses generate bias-adjusted measures but these are not much used; this may change with the availability of the E-value (for evidence for causality in observational studies), appealing for its ease of calculation. However, as currently proposed, the E-value has some practical limitations that may reduce its use.

Reflection on modern methods: selection bias-a review of recent developments.

Selection bias remains a more difficult bias to understand than confounding or measurement error. Past definitions have not always been illuminating and a simple method (such as the change-in-estimate method for confounding) has not been available to determine its presence and magnitude in the study sample. A better understanding of the nature of the bias has led to the definition of endogenous selection bias.

Advanced parental age as risk factor for childhood acute lymphoblastic leukemia: results from studies of the Childhood Leukemia International Consortium.

Advanced parental age has been associated with adverse health effects in the offspring including childhood (0-14 years) acute lymphoblastic leukemia (ALL), as reported in our meta-analysis of published studies. We aimed to further explore the association using primary data from 16 studies participating in the Childhood Leukemia International Consortium. Data were contributed by 11 case-control (CC) studies (7919 cases and 12,942 controls recruited via interviews) and five nested case-control (NCC) studies (8801 cases and 29,690 controls identified through record linkage of population-based health registries) with variable enrollment periods (1968-2015).

Living on a farm, contact with farm animals and pets, and childhood acute lymphoblastic leukemia: pooled and meta-analyses from the Childhood Leukemia International Consortium.

The associations between childhood acute lymphoblastic leukemia (ALL) and several factors related to early stimulation of the immune system, that is, farm residence and regular contacts with farm animals (livestock, poultry) or pets in early childhood, were investigated using data from 13 case-control studies participating in the Childhood Leukemia International Consortium. The sample included 7847 ALL cases and 11,667 controls aged 1-14 years. In all studies, the data were obtained from case and control parents using standardized questionnaires.

Analysis of case-parent trios for imprinting effect using a loglinear model with adjustment for sex-of-parent-specific transmission ratio distortion.

Transmission ratio distortion (TRD) is a phenomenon where parental transmission of disease allele to the child does not follow the Mendelian inheritance ratio. TRD occurs in a sex-of-parent-specific or non-sex-of-parent-specific manner. An offset computed from the transmission probability of the minor allele in control-trios can be added to the loglinear model to adjust for TRD.

Traumatic Brain Injury in the Workplace.

Objectives: Work-related traumatic brain injuries (TBIs) are not well documented in the literature. Published studies mostly rely on worker databases that fail to provide clinically relevant information. Our objective is to describe the characteristics of hospitalized patients and their work-related TBI.

Parental alcohol consumption and risk of leukemia in the offspring: a systematic review and meta-analysis.

Parental alcohol consumption before and during pregnancy has been linked to adverse outcomes in the offspring including leukemogenesis. We, therefore, aimed to systematically assess and quantitatively synthesize published data on the association of paternal consumption during preconception and maternal consumption during pregnancy with leukemia risk in childhood (0-14 years). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched PubMed (until February 2016) and the reference lists of the relevant studies.

Analysis of Case-Parent Trios Using a Loglinear Model with Adjustment for Transmission Ratio Distortion.

Transmission of the two parental alleles to offspring deviating from the Mendelian ratio is termed Transmission Ratio Distortion (TRD), occurs throughout gametic and embryonic development. TRD has been well-studied in animals, but remains largely unknown in humans. The Transmission Disequilibrium Test (TDT) was first proposed to test for association and linkage in case-trios (affected offspring and parents); adjusting for TRD using control-trios was recommended.

Assessment of occupational risks to extremely low frequency magnetic fields: Validation of an empirical non-expert approach.

The expert method of exposure assignment involves relying on chemists or hygienists to estimate occupational exposures using information collected on study subjects. Once the estimation method for a particular contaminant has been made available in the literature, it is not known whether a non-expert, briefly trained by an expert remaining available to answer ad hoc questions, can provide reliable exposure estimates. We explored this issue by comparing estimates of exposure to extremely low frequency magnetic fields (ELF-MF) obtained by an expert to those from a non-expert.

Caesarean delivery and risk of childhood leukaemia: a pooled analysis from the Childhood Leukemia International Consortium (CLIC).

Background: Results from case-control studies have shown an increased risk of acute lymphoblastic leukaemia (ALL) in young children born by caesarean delivery, and prelabour caesarean delivery in particular; however, an association of method of delivery with childhood leukaemia subtypes has yet to be established. We therefore did a pooled analysis of data to investigate the association between childhood leukaemia and caesarean delivery.

Methods: We pooled data from 13 case-control studies from the Childhood Leukemia International Consortium done in nine countries (Canada, Costa Rica, Egypt, France, Germany, Greece, Italy, New Zealand, and the USA) for births from 1970-2013.

Home paint exposures and risk of childhood acute lymphoblastic leukemia: findings from the Childhood Leukemia International Consortium.

Purpose: It has been suggested that home paint exposure increases the risk of childhood acute lymphoblastic leukemia (ALL).

Methods: We obtained individual level data from eight case-control studies participating in the Childhood Leukemia International Consortium. All studies had home paint exposure data (sometimes including lacquers and varnishes) for the pregnancy period with additional data for the 1-3-month period before conception in five, the year before conception in two, and the period after birth in four studies, respectively.

Favourable IFNL3 genotypes are associated with spontaneous clearance and are differentially distributed in Aboriginals in Canadian HIV-hepatitis C co-infected individuals.

Canadian Aboriginals are reported to clear Hepatitis C (HCV) more frequently. We tested the association of spontaneous clearance and three single nucleotide polymorphisms (SNPs) near the Interferon-lambda 3 (IFNL3) gene (rs12979860, rs8099917, functional variant rs8103142) and compared the SNP frequencies between HIV-HCV co-infected whites and Aboriginals from the Canadian Co-infection Cohort. HCV treatment-naïve individuals with at least two HCV RNA tests were included (n = 538).

Occupational exposure to endocrine disruptors and lymphoma risk in a multi-centric European study.

Background: Incidence rates of lymphoma are usually higher in men than in women, and oestrogens may protect against lymphoma.

Methods: We evaluated occupational exposure to endocrine disrupting chemicals (EDCs) among 2457 controls and 2178 incident lymphoma cases and subtypes from the European Epilymph study.

Results: Over 30 years of exposure to EDCs compared to no exposure was associated with a 24% increased risk of mature B-cell neoplasms (P-trend=0.

Childhood acute lymphoblastic leukemia and indicators of early immune stimulation: a Childhood Leukemia International Consortium study.

The associations between childhood acute lymphoblastic leukemia (ALL) and several proxies of early stimulation of the immune system, that is, day-care center attendance, birth order, maternally reported common infections in infancy, and breastfeeding, were investigated by using data from 11 case-control studies participating in the Childhood Leukemia International Consortium (enrollment period: 1980-2010). The sample included 7,399 ALL cases and 11,181 controls aged 2-14 years. The data were collected by questionnaires administered to the parents.

Maternal supplementation with folic acid and other vitamins and risk of leukemia in offspring: a Childhood Leukemia International Consortium study.

Background: Maternal prenatal supplementation with folic acid and other vitamins has been inconsistently associated with a reduced risk of childhood acute lymphoblastic leukemia (ALL). Little is known regarding the association with acute myeloid leukemia (AML), a rarer subtype.

Methods: We obtained original data on prenatal use of folic acid and vitamins from 12 case-control studies participating in the Childhood Leukemia International Consortium (enrollment period: 1980-2012), including 6,963 cases of ALL, 585 cases of AML, and 11,635 controls.

Reproductive factors and non-Hodgkin lymphoma: a systematic review.

Considerable efforts have been made to elucidate non-Hodgkin lymphoma's (NHL) etiology during the last decades. Some evidence points to an association with reproductive factors, as incidence rates for most NHL subtypes are usually higher in men than in women, and several subtypes express hormonal receptors. Although the evidence is not compelling, some studies show an inverse association with gravidity.

Incidence and risk factors for inhibitor development in previously untreated severe haemophilia A patients born between 2005 and 2010.

The objective of this study was to evaluate the inhibitor development (ID) in previously untreated patients (PUPs) with severe haemophilia A (FVIII ≤ 0.01 IU mL(-1) ). All Canadian Haemophilia Treatment Centres completed a questionnaire on patients born between September 2005 and August 2010 and followed for up to 7 years.

Parental occupational pesticide exposure and the risk of childhood leukemia in the offspring: findings from the childhood leukemia international consortium.

Maternal occupational pesticide exposure during pregnancy and/or paternal occupational pesticide exposure around conception have been suggested to increase risk of leukemia in the offspring. With a view to providing insight in this area we pooled individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format.