University of California, Berkeley, School of Public Health, 1995 University Avenue, Suite 460, Berkeley, CA 94704-1070, USA.
Cancer Epidemiol. 2013 Jun;37(3):336-47. doi: 10.1016/j.canep.2012.12.011. Epub 2013 Feb 9.
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.
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.
By September 2012, CLIC included 22 studies (recruitment period: 1962-present) from 12 countries, totaling approximately 31000 cases and 50000 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.
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.
急性白血病是 15 岁以下儿童中最常见的癌症；80%为急性淋巴细胞白血病（ALL），17%为急性髓细胞白血病（AML）。儿童白血病根据细胞遗传学和分子特征进一步多样化，这可能与不同的病因有关。全球开展的病例对照研究，特别是 ALL，收集了大量有关潜在危险因素的数据，在一些研究中还收集了生物标本。越来越多的证据表明，感染/免疫因素、胎儿生长和几种环境因素在儿童 ALL 的病因中起作用。与其他复杂疾病一样，儿童白血病的风险可能受到基因和环境暴露的独立和相互作用的影响。虽然一些研究分析了遗传变异的作用，但很少有研究有足够的能力来研究基因-环境相互作用。
儿童白血病国际联盟（CLIC）成立于 2007 年，旨在通过汇集来自独立研究的数据，促进对罕见暴露、基因-环境相互作用和亚型特异性关联的研究。
截至 2012 年 9 月，CLIC 包括来自 12 个国家的 22 项研究（招募期：1962 年至今），总计约 31000 例病例和 50000 例对照。其中，19 项病例对照研究收集了详细的流行病学数据，15 项研究收集了儿童的 DNA 样本，13 项研究收集了儿童及其父母三人间的 DNA 样本。两项基于登记的研究和一项包含出生时和/或诊断时常规获得的医院记录的研究只有有限的访谈数据或生物标本。
CLIC 提供了一个独特的机会，可以填补有关环境和遗传危险因素、暴露关键期、基因-环境相互作用的影响以及不同种族群体中特定白血病亚型之间关联的知识空白。
