Risk Factors Of Childhood Leukemia In China: A Meta Analysis

Objective: Leukemia,a kind of cancer with high morbidity for children under 15 years of age,and its mortality rate ranks first in childhood malignancies,resulting in a huge burden and trauma for social and family.The etiology of leukemia is inconclusive neither domestic nor international.We used Meta analysis to systematically evaluate the influence of hereditary predisposition,birth condition,physical and chemical environment,biology,medication,parental and other factors on childhood leukemia.We searched Pubmed,Embase,Web of Science,Cochrane Library,CNKI,Wanfang Data,VIP,and CBM databases for case-control studies of leukemia risk factors with Chinese children,from database building to July 2016.Taking into account some studies may include both children and adults,so the search terms did not contain "children","child" and so on,to be manually selected after the search.English retrieval formula as:(leukemia[Title/Abstract])AND risk factor*[Title/Abstract],and Chinese retrieval formula as: TI=(('leukemia' * 'risk factor' + 'leukemia' * 'risk' + 'leukemia ' * 'incidence')-('infection' + 'relapse')),and hand-searched in accordance with the references.We filtered the literatures according to the inclusion and exclusion criteria.Endnote X7 and Excel database were used to manage the literatures;Review Manager 5.3 was used to do Meta-analysis and Stata 12.0 to do hypothesis test for funnel plots.The effect indicators were Odds ratios(OR)and 95% CI.We compared different effect models and drew funnel plots to do sensitivity analysis and publication bias analysis,and used Begg's and Egger's test to check if the funnel plots are in symmetry.Results: A total of 18 studies were included with 2428 cases and 3209 controls.The top 10 combined OR values were: the maternal antibiotic drugs(OR = 5.37 [2.82,10.23])and anti-inflammatory drugs(OR = 4.55 [2.29,9.05])using during pregnancy,children exposure to paint(OR = 3.71 [1.62,8.53])and indoor pesticides(OR = 3.48 [2.5 6,4.74]),maternal exposure to pesticides during pregnancy(OR = 3.00 [ 1.78,5.08]),residential environment pollution(OR = 2.83 [1.92,4.17]),home decoration(OR = 2.65 [1.81,3.86]),residential power lines exposure(OR = 2.64 [1.73,4.03]),maternal X-ray exposure during pregnancy(OR = 2.60 [2.00,3.38])and children exposure to mosquito repellent(OR=2.49 [1.65,3.77]).No statistically significant factors were: maternal drinking history(OR = 0.51 [0.12,2.16]),children regularly taking antibiotics or anti-inflammatory drugs(OR = 1.00 [0.47,2.15]),childbearing age of father(OR = 1.00 [0.92,1.09]),father drinking history(OR = 1.08 [0.92,1.27]),father smoking during pregnancy(OR = 1.26 [0.93,1.71]),skin disease of children(OR = 1.50 [0.72,3.14]),children taking chloramphenicol(OR = 1.51 [0.90,2.54]),and family history of blood disease(OR = 1.59 [0.84,2.97]).Conclusions: Familial predisposition,children and parents' exposure to benzene,formaldehyde,lead,ionizing and electromagnetic radiation,maternal drug use and cigarette exposure during pregnancy,maternal and children's exposure to pesticides are the risk factors of childhood leukemia.While family blood disease history,children's skin disease history,children's medication,parents' drinking during pregnancy,father smoking,and childbearing age of father still cannot be explained as risk factors of children leukemia.