Pediatric cancer survivors at risk for diseases that predispose them to cardiovascular disease
Survivors of pediatric cancer are at greater risk for
high cholesterol, diabetes and high blood pressure, all of which predispose them
to heart disease. These risk factors for heart disease are being found at an earlier
age than in the general population, according to research published in Cancer
Epidemiology, Biomarkers & Prevention, a journal of the American Association
for Cancer Research.
Lillian R. Meacham, M.D., medical director of the Cancer
Survivor Program and professor of pediatrics at Emory University, extracted data
from the Childhood Cancer Survivor Study, which included 8,599 cancer survivors
and 2,936 of their siblings.
"In data previously published from the Childhood Cancer
Survivor Study, pediatric cancer survivors were found to be at almost 10-fold
greater risk for cardiovascular disease than their non-survivor counterparts,"
said Meacham. "In this study we identified whether the predisposing risk factors
for cardiovascular disease - obesity, hypertension, hyperlipidemia and diabetes
- were present at higher rates compared to siblings. If the risk factors could
be recognized and treated early it is hoped some of the long-term cardiac side
effects could be averted."
Meacham found that cancer survivors were nearly twice
as likely as their siblings to take medication for high blood pressure, 60 percent
more likely to take cholesterol medication and 70 percent more likely to have
diabetes.
Radiation treatment may be playing a role in the development
of risk factors for cardiovascular disease, Meacham said. Total body irradiation
was linked with a 5.5-fold increased risk and chest and abdomen radiation a 2.2-fold
increased risk of cardiovascular risk factor clustering, which when present is
associated with subsequent cardiovascular disease.
"Mechanistically, we are not yet sure why this is, but
the association is definitely there," said Meacham.
Researchers examined the presence of cardiovascular risk
factors and found that physical inactivity among cancer survivors was linked with
a 70 percent increased risk for cardiovascular risk factor clustering. Older age
at the time of the study was linked to an 8.2-fold increased risk for cardiovascular
risk factor clustering among survivors compared with children who had never had
cancer.
"These risk factors are manifesting at about age 32,
which is much younger than a non-cancer survivor would exhibit signs of cardiovascular
risk factors," said Meacham. "Some have suggested that when you are a cancer survivor
there are parts of you that wear out early, so we need to be vigilant about our
follow-up of these patients in order to find these late effects early and intervene."
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