Panel Says No Evidence Growth Hormones Are Linked to Leukemia
There is no convincing evidence that leukemia is linked to growth hormone treatments in
children, a panel of scientists from the National Cooperative Growth Study (NCGS)
concluded in a recent report.
Several studies over nine years have shown no proof that the hormones caused an
increased risk of leukemia in growth-hormone treated children without known risk factors,
the panel said in a report in the Journal of Pediatrics.
Focusing on the potential link between growth hormone treatment and childhood leukemia,
the panel said that its study did not identify actual cases of leukemia in higher than
expected numbers in children without known risk factors. "In a cohort of more than
24,000 children treated with growth factors in the U.S. and Canada, we found only 3 cases
of leukemia in children without prior risk factors, a number not significantly different
from the 3.42 cases expected" in the general population of children, the panel
reported.
The debate over the relationship between growth hormone treatment and leukemia began in
1988, when researchers in Japan reported that children receiving hormones (to correct
short stature or growth impairment) had elevated rates of leukemia. Several later reports,
however, indicated that any possible increase in leukemia during growth hormone treatment
appeared to be limited to those patients with already existing risk factors for leukemia,
according to the authors of the NCGS study. The NCGS is a large surveillance study that
began in 1985 after the approval of growth hormone therapy in the U.S.
Leukemia is the most common form of cancer in children. About 2,100 new cases of
leukemia in children are diagnosed each year in the U.S. The cause of leukemia is children
is not evident, but several risk factors include exposures to high doses of irradiation,
uncommon genetic disorders, and treatment with certain types of drugs.
(Journal of Pediatrics, July 1997: pp. S32-S36.)
