For cancer survivors who have undergone the struggle of
chemotherapy, the road to complete recovery may be a bit longer
than expected.
A recent imaging study at UCLA showed a relationship between
chemotherapy treatment and changes in brain metabolism in breast
cancer patients. At least 25 percent of the patients in the study
experienced mental fogginess lasting up to 10 years after
chemotherapy treatment, said Daniel Silverman, the study’s
lead researcher.
“What is most common for chemo brain patients are
inabilities to concentrate, multitask and remember things the way
they used to be able to,” he said.
Though the study of “chemo brain” was not considered
important a decade ago, it has come into the spotlight recently
because cancer patients are now being treated with chemotherapy
earlier on. Though the earlier use of chemotherapy serves to
prevent the spread of cancer to other parts of the body, it also
results in greater occurrences of side effects, Silverman said.
“The single biggest impediment to the quality of life of
these women is cognitive dysfunction,” Silverman said.
Renae Taylor, a 46-year-old breast cancer survivor, said she
experienced fogginess and fatigue after chemotherapy.
“At one point, I had to take six months off from work
because my job demands high attention to detail and I felt like I
couldn’t focus,” Taylor said.
Though the effects of chemotherapy have been examined
extensively, this study is the first to look at brain metabolism in
greater depth.
The study consisted of 34 women, 13 of whom were controls who
did not have cancer and had not undergone chemotherapy. The other
21 had chemotherapy treatments within the past five to 10 years,
said co-author Patricia Ganz, an oncologist at the UCLA Jonsson
Comprehensive Cancer Center.
Each patient received seven positron emission tomography scans
to measure blood flow during memory tasks. The study also gauged
brain metabolism when the patients were at rest, Silverman
said.
“The results showed that when the patients are just lying
there, the women who had chemotherapy exhibited less brain activity
in the frontal cortex,” Silverman said.
Other psychological tests examined short-term memory, verbal
ability, judgment, abstract reasoning and visual and spatial
abilities.
“The key test was the memory test,” Silverman said.
“There was a jump in blood flow in those exhibiting symptoms
of the chemo brain. This is because their brains have to work
harder than the controls’ (brains do).”
While the study was enough to show a significant relationship
between chemotherapy treatment and decreased brain metabolism,
further studies would have to be conducted in this field to reach a
more specific degree of knowledge, Ganz said.
“This is just a pilot study, but it is too small to make
any definite conclusions on the value of chemotherapy,” Ganz
said. “We have received a grant that will allow us to not
only look at a larger number of people but also research other
areas.”