The Childhood Leukemia International Consortium

Abstract

Background Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case–control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene–environment interactions. Objectives The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote investigations of rarer exposures, gene–environment interactions and subtype-specific associations through the pooling of data from independent studies. Methods By September 2012, CLIC included 22 studies (recruitment period: 1962–present) from 12 countries, totaling approximately 31 000 cases and 50 000 controls. Of these, 19 case–control studies have collected detailed epidemiologic data, and DNA samples have been collected from children and child–parent trios in 15 and 13 of these studies, respectively. Two registry-based studies and one study comprising hospital records routinely obtained at birth and/or diagnosis have limited interview data or biospecimens. Conclusions CLIC provides a unique opportunity to fill gaps in knowledge about the role of environmental and genetic risk factors, critical windows of exposure, the effects of gene–environment interactions and associations among specific leukemia subtypes in different ethnic groups.

Childhood Leukemias in Khyber Pakhtunkhwa and Afghan Children Visiting to Hayatabad Medical Complex Hospital

“…In present study, acute lymphoblastic leukemia was found predominant childhood leukemia about 74.3% children suffer from ALL, followed by 22.0% AML, 2.44% CML. Current study result slightly different from the study of Metayer et al in 2013 that revealed 80% were acute lymphoblastic leukemia, 17% were acute myeloid leukemia and 2% were chronic myeloid leukemia [12].…”

Maternal Supplementation with Folic Acid and Other Vitamins and Risk of Leukemia in Offspring

“…Study design and characteristics of participants in individual studies have been described previously. 18 A total of 19,183 children were available for analysis (6,963 cases of ALL, 585 cases of AML, and 11,635 controls). Information on immunophenotype was available for 84% of ALL, including 5,193 children diagnosed with precursor B-cell ALL and 678 with T-cell ALL.…”

“…To overcome the limitations of previous studies, we pooled original data on prenatal intake of folic acid and vitamins from 12 case-control studies participating in the Childhood Leukemia International Consortium (CLIC) 18 , and examined the associations with childhood ALL (overall and by immunophenotype) and AML. We also evaluated the modifying effects of education level as a marker of nutritional status 19-23 , and of alcohol consumption, which is known to modify folate metabolism.…”

Protective effect of breastfeeding against childhood leukemia in Zhejiang Province, P. R. China: a retrospective case-control study

“…There are two main types of childhood leukemia, acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML). AML is not very common, accounting for about 17% of childhood leukemia [2]. Its etiology and pathogenesis remain unknown, which may be linked to genetic factors and environmental factors including infection, radiation, and living conditions [3].…”