Parental smoking may boost childhood leukemia risk

[unseennude]

The risk of leukemia in childhood appears to be increased when fathers smoke, even before conception, and with exposure to smoking postnatally, researchers report in the June issue of the American Journal of Epidemiology.

Dr. Jeffrey S. Chang of the University of California, Berkeley and colleagues note that cigarette smoking has been linked to leukemia in adults, but the association in children has remained unclear.

To investigate further, the researchers conducted a case-control study of 287 children with acute lymphoblastic leukemia (ALL), 46 with acute myeloid leukemia (AML) and 416 controls.

The researchers found that maternal smoking alone was not associated with an increased risk of either type of leukemia, but paternal preconception smoking was strongly associated with the risk of AML (odds ratio, 3.84) and suggestive of an association with ALL (odds ratio, 1.32).

However, the investigators observe that the strong association with AML was based on data on only 16 cases and 8 controls.

The researchers also found a greater risk of ALL than that associated with paternal preconception smoking alone, when this was combined with maternal postnatal smoking or postnatal passive smoking exposure.

Summing up, the team notes that the public is aware of the detrimental effect of maternal smoking on the fetus. "The knowledge of a potentially harmful effect of paternal smoking exposure," they conclude, "may provide men with a stronger incentive to quit."