21 April 2010
A child whose grandmother smoked has double the risk of childhood cancer as the grandchild of a non-smoker.
This increased relative risk of cancer added to the evidence that damage from tobacco smoke might be passed down through generations of a family, researchers said.
The study of 128 children with cancer and 128 matched controls (children without cancer) was conducted in Spain by Spanish and American researchers (Journal of Paediatrics and Child Health 2010; in press).
Exposure and use of tobacco was determined over 3 generations, with the smoking habits of mothers and maternal grandmothers being assessed.
Sixty per cent of mothers of children with neuroblastoma (a type of cancer that forms in nerve tissue) were smokers, and 27 per cent of grandmothers of children with acute lymphoblastic leukaemia were smokers, researchers found.
Maternal grandmother tobacco consumption and maternal consumption during pregnancy were significantly associated with an increased risk of childhood cancer.
The results suggested not only in-utero exposure (mother’s smoking), but passive exposure during the development of eggs within the ovaries of the mother (grandmother smoking), increased the risk of childhood malignancy, the researchers said.
Studies in rodents had shown that exposure to chemical carcinogens (cancer-causing agents) during pregnancy resulted in increased tumour incidence in subsequent generations, they said.
“This topic is highly controversial but needs to be carefully assessed,” they wrote.
The global increase in childhood cancers might have been caused by the previous decades’ increase in women taking up smoking, they suggested.
Last Reviewed: 21 April 2010