Risk factors of childhood acute lymphoblastic leukaemia: a case-control study

ABSTRACT

The Alexandria Cancer Registry in 1992 reported that Acute Lymphoblastic Leukaemia [ALL] constituted 24.7% of childhood malignancies among male children and 19.2% among female children. This relative high magnitude of ALL in Egypt needs to be studied in depth. The aim is to reveal the different risk factors related to development of the childhood ALL and provide essential data for planning preventive programs. A hospital based case control study was carried out in two hospitals Alexandria University Children Hospital and School Students Hospital. Data collection was carried using a structured interview schedule. All newly diagnosed cases of ALL during the period from March, 2003 - 31[st] December, 2004 were included in the case series [90 cases]. For each case, two controls were randomly recruited [180] of matched age and sex with ALL cases. The mean age of cases was 4.58 +/- 2.35 years. The ratio of boys to girls was 2.11. The final model of multiple logistic regression analysis revealed that first born or only born child and birth weight >/= 3500 gm, consanguinity, fathers' smoking before conception, child exposure to hydrocarbons/benzene, electromagnetic field sources, family history of blood cancers, maternal history of prior fetal losses, some infections, allergies, exposure to radiation or intake of medications during pregnancy, also different childhood diseases all were significant contributing factors that increased risk of ALL, whereas exclusive breast-feeding and early day-care attendance were associated significantly with decreased risk of ALL. The consistency of results of current work with several other research works can support the identification of specific possible risk factors. The research points to specific environmental, social, health and biological factors that need to be addressed. Further research is needed. The data presented in this work can be used to formulate hypotheses