摘要：Leukemia accounts for a third of all cancers in children under the age of 15, mostly affecting industrialized countries, being the B-precursor acute lymphoblastic leukemia (pB-ALL) the most common type. The disease commonly strikes young children at the age of two to five years, and is treated with aggressive chemotherapy. In recent decades, more effective treatments have boosted survival rates and reduced mortality for childhood leukemia. However, according to SEER data from the National Cancer Institute, the incidence of lymphoblastic leukemia (ALL) in 0-14 year-old US children increased from 2.2 per 100,000 in 1975 to 4.0 per 100,000 in 2005. This might be caused in part due to better cancer registries but there is little doubt that the real incidence of this "modern life-style" malignancy also rose. Hence, preventive strategies are clearly superior to any therapy improvement. Environmental exposures came into the focus of many epidemiologists who initiated a number of well-conducted studies aiming to elucidate the etiological role of infection, nuclear power-plants, background terrestrial irradiation and many other putative factors.
