Links in childhood leukaemia

Use of medication during pregnancy and risk of childhood leukemia (Canada)

OBJECTIVE

To examine risk of childhood acute lymphoblastic leukemia (ALL) associated with maternal use of medications during pregnancy; in particular medications known or suspected to be teratogenic.

METHODS

Seven hundred and eighty nine children (< 15 years old) diagnosed with ALL in the province of Quebec between 1980 and 2000 were recruited for study. A similar number of population based controls matched to cases (1:1) by sex and age were chosen from family allowance or health insurance files. Information was gathered via telephone interview with the subjects' parents. Data were analyzed using conditional logistic regression.

RESULTS

Risk of childhood ALL was significantly increased in the offspring of mothers who reported using any medication (adjusted odds ratio (OR(adj)) = 1.3, 95% CI = 1.0-1.6) or any teratogenic medication (OR(adj) = 1.4, 95% CI = 1.1-1.9) during pregnancy. Among specific medication categories, only central nervous system depressants were associated with a significantly increased risk, although elevated odd ratios were found for anti-epileptics, immunosuppressants, oral contraceptives, and illicit drugs. Risk associated with use of teratogenic medications was higher with increased dose and in children diagnosed before two years of age.

CONCLUSION

A modest increase in risk of ALL was found among children of mothers who used medication during pregnancy.

Patterns of acute leukaemia occurrence among children in the Chernobyl region

BACKGROUND

The Chernobyl nuclear accident of 1986 released large quantities of radioactive material causing widespread contamination. In the Ukraine alone, more than 4 million people were exposed to radiation. The exact health consequences of this exposure are still being assessed.

METHODS

To ascertain the effect of in utero radiation exposure and the development of leukaemia, a review was undertaken of leukaemia sub-types occurring among children born in the year of the accident (1986) and followed 10 years post-exposure. A comparison was made of leukaemia cumulative incidence rates among children from both an exposed and unexposed oblast.

RESULTS

Rate ratios (RR) for the all cell types grouping of leukaemia revealed that rates in the exposed Oblast were significantly elevated for females, males and both genders combined. Rates of acute lymphoblastic leukaemia (ALL) were dramatically elevated for males and to a lesser extent for females. For both genders combined, the RR for ALL was more than three times greater in the exposed compared to the unexposed region.

CONCLUSION

Study results suggest that the increased risk of leukaemia and acute leukaemia among those children born in 1986 and resident in radioactively contaminated territories may be associated with exposure to radiation resulting from the Chernobyl accident.