Fetal exposure to dietary carcinogens and risk of childhood cancer: what the NewGeneris project tells us

Cancer in childhood is rare. Globally, there are around 175 000 new cancer cases a year among children aged 0-14 years.1 However, in Europe, since the 1950s the incidence of cancer in this age group has increased by about 1% a year, with leukaemia, brain tumours, and lymphomas accounting for most cases.2 The increases in incidence of lymphoid leukaemia, in particular, are more apparent in European than in Asian or African children.3 The development of childhood cancer thus seems to be affected by both genetic and environmental factors. Given that the highest incidences of childhood leukaemia are reported in children younger than 6-7 years, that the latency period of leukaemia in children is relatively short,4 and that adverse genetic events in utero have been shown to give rise to leukaemia in childhood,5 we hypothesised that fetal exposure to environmental carcinogens may be an underlying cause. Diet is an important source of carcinogenic compounds because of the accumulation of environmental carcinogens within the food chain (dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs)), as well as of formation of carcinogens such as PAHs, heterocyclic amines, and acrylamide during baking, frying, and grilling of food.6 The New Generis (Newborns and Genotoxic Exposure Risks) project therefore set out to investigate whether intake of dietary carcinogens by the pregnant mother leads to exposures of the fetus and initiates adverse biological responses that can induce cancer in later childhood.

Investigation of this hypothesis in an epidemiological study would require a huge sample size because of the relatively low incidence of childhood cancer (about 140 cases per million children).2 3 Case-control studies have been informative but also have limitations. …