BUFFALO, NY – The first reported population-based study of childhood leukemia among persons exposed to radiation following the explosion of the Chernobyl Nuclear Power Plant April 26, 1986, has uncovered “no convincing evidence” of an increased risk of childhood leukemia among participants. This is the major finding of an International Consortium for Research on the Health Effects of Radiation study published in the International Journal of Epidemiology (doi:1093/ije/dy1220), November 3, 2005.

“This is the first such study of childhood leukemia among persons exposed to radiation from the Chernobyl accident conducted in the contaminated regions of Ukraine, Belarus and Russia using common methodology and based on individual estimates of radiation dose,” according to Arthur M. Michalek, PhD, senior vice president for educational affairs, at Roswell Park Cancer Institute (RPCI), and a member of the Consortium. RPCI colleagues Kirsten B. Moysich, PhD, Martin C. Mahoney, MD, PhD, and Philip L. McCarthy, MD, who led the study’s Leukemia Diagnostic Committee, were also members of the Consortium.

The study – funded by the Department of the Navy – also found that the level of radiation dose received by participants in all three countries was relatively low (mean <10 mGy). These doses were much less than the researchers originally expected, but they point out that they are consistent with earlier estimates of exposure reported in other studies.

Four hundred twenty-one (421) confirmed cases of acute leukemia (AL) diagnosed between April 26, 1986 and December 31, 2000, in patients who were in utero or less than six years of age at the time of the accident were studied. Cases identified from seven contaminated oblasts (counties) in Belarus, Russia and the Ukraine were independently verified by an expert panel of morphologists and hematologists. Two controls were matched to each case based on sex, birth year and residence.

Among the 421 cases included in the study, 311 (74%) were diagnosed with acute lymphoid leukemia and 86 with acute myeloid leukemia. “This geographic distribution of leukemia subtypes is generally consistent with what would be expected based on general population estimates, given the age restriction for inclusion in the present study,” notes Dr. Moysich.

“This multinational study provided a unique opportunity to assess the relation between exposure to radiation from the Chernobyl disaster and the development of acute leukemia among children in the Former Soviet Union (FSU),” according to Dr. Mahoney. “Interactions with colleagues from the FSU, the Fred Hutchinson Cancer Research Center and other institutions were especially rewarding.”

Roswell Park Cancer Institute, founded in 1898, is the nation’s first cancer research, treatment and education center and is the only National Cancer Institute- designated comprehensive cancer center in Upstate New York. RPCI is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation’s leading cancer centers. For more information, visit the RPCI website at www.roswellpark.org, call 1-877-ASK-RPCI (1-877-275-7724).

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