Study: Radiation Increases Risk of Stroke
Reported June 22, 2009
(Ivanhoe Newswire) -- Patients treated for Hodgkin lymphoma with
radiation therapy have a substantially higher risk of stroke, according to a
new study published in the Journal of the National Cancer Institute.
Radiation to the neck and mediastinum was associated with increased risk,
whereas chemotherapy was not.
In order to quantify the long-term risks, Flora E. van Leeuwen, Ph.D., of
the Department of Epidemiology at the Netherlands Cancer Institute in
Amsterdam, and colleagues performed a retrospective cohort study among 2,201
Hodgkin lymphoma survivors. The patients, who had survived at least 5 years
from the time of diagnosis, had received radiation therapy between 1965 and
1995 before age 51. The researchers compared incidence rates of clinically
verified stroke and TIA in this cohort with rates in the general population.
After a median follow-up of almost 18 years, the incidence rate for stroke
was 2.2 times the incidence in the general population. For TIA, it was 3.1.
Risks also remained elevated, compared to those in the general population
after prolonged follow-up.
"For young survivors of Hodgkin lymphoma, who are at especially increased
risk of stroke and TIA, physicians should consider appropriate risk-reducing
strategies, such as treatment of hypertension and lifestyle changes to
reduce the risk of stroke and TIA," the authors write.
In an accompanying editorial, Dan L. Longo, M.D., of the National Institute
on Aging, part of the National Institutes of Health in Bethesda, Md.,
discussed the study's contribution to the "already overwhelming evidence
that radiation therapy in Hodgkin's disease is short-sighted ."
He applauded the detailed medical documentation and follow-up of the
patients in the study, but noted that the relationship of stroke to
radiation doses was not examined.
According to Longo, results of this study should affect a physician's choice
of primary treatment.
"Unfortunately, given the life-long increased risks of late effects that
have been documented from the use of radiation therapy, we simply cannot
keep exposing patients to risk without clear benefit while we wait for
safety data to be produced," he wrote. "With an alternative therapy at hand
that is just as effective ... it is simply unjustified to keep using a toxic
modality for the next 10-20 years."
SOURCE: Journal of the National Cancer Institute, June 17, 2009