- NEW YORK (Reuters Health)
- Years after receiving chemotherapy, survivors of breast cancer and
lymphoma
score worse on some tests of mental ability than those who had only surgery
or radiation therapy, researchers say.
-
- Previous studies have documented that problems with
memory,
concentration, attention and learning, collectively known as cognitive
dysfunction, occur in some cancer patients shortly after chemotherapy and
are still present approximately 2 years later.
-
- The new research suggests that these problems--although
relatively subtle--might last indefinitely, Dr. Tim A. Ahles and his
colleagues
report in a recent issue of the Journal of Clinical Oncology. At the time
of their study, it had been approximately 10 years, on average, since the
cancer patients had received chemotherapy.
-
- "The major message is that survivors' reports of
cognitive problems should be taken seriously," according to
Ahles.
-
- The investigators gave standardized tests of cognitive
function to two groups of cancer survivors: 71 who had received
chemotherapy
and 57 who had undergone surgery and/or radiation therapy. All had been
treated at least 5 years previously. In each group, about half of the
patients
had been treated for breast cancer and the others had been treated for
lymphoma, which is a type of cancer that arises in the lymph nodes or
similar
tissue. Most patients, 85%, had needed only one course of standard-dose
chemotherapy.
-
- The research team, which is based at Dartmouth-Hitchcock
Medical Center, Lebanon, New Hampshire, found that more than twice as many
survivors in the chemotherapy group did poorly on the cognitive tests
compared
with survivors who were given other types of treatment. That held true
even after the researchers defined "low performance" in several
different ways. An analysis showed that 24% to 50% of those treated with
chemotherapy were in the low performance range, compared with 5% to 23%
of those who did not get chemotherapy.
-
- Even though there was a difference between the treatment
groups, "performance was generally within the normal range,"
the scientists report in their journal article. So the effects of
chemotherapy
can be subtle, but even so, "they can be very significant to the
individual
and can have a negative impact on work and school performance," Ahles
told Reuters Health.
-
- Doctors don't yet know how chemotherapy affects the
brain,
whether only some chemotherapy drugs are toxic to the brain, or which
subgroups
of patients are at risk of long-term cognitive dysfunction. But even so,
the research team emphasizes, "the survival benefits of chemotherapy
far outweigh the potential risks to cognitive functioning for most
patients."
-
- Also, "just because someone has received
chemotherapy,
it does not mean that the chemotherapy caused the cognitive problem,"
Ahles pointed out. "Problems with memory and concentration can be
caused by medications, other medical problems, sleep disorders and
psychological
problems, for example depression and anxiety. Therefore, other potential
causes of the cognitive problems need to be evaluated. This is particularly
important since many of these other causes are treatable."
-
- Ahles added that "separating out the long-term
effects
of chemotherapy from the effects of normal aging can be difficult. However,
survivors who report cognitive problems typically say that the problem
started when they received chemotherapy and never got better."
-
- SOURCE: Journal of Clinical
Oncology 2002;20:485-493.
- Copyright © 2002 Reuters Limited. All rights
reserved.
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