by Julie Steenhuysen
November 14, 2011
Study confirms that many
survivors of breast cancer chemotherapy treatments
suffer from brain damage.
Women who survive breast cancer after undergoing chemotherapy may
also have to contend with impairments in attention, memory and
planning skills, U.S. researchers said Monday.
They said women who had undergone chemotherapy for breast cancer had
significantly less activity in parts of the brain responsible for
executive functioning tasks compared with breast cancer patients who
were not treated with chemotherapy.
Among those treated with chemotherapy, the study also found a strong
correlation between women who complained they were having trouble
with memory and thinking skills and actual deficits in these regions
of the brain.
The study may help explain why many breast cancer patients complain
of "chemo brain" - a term used to describe foggy thinking and memory
lapses following treatment with chemotherapy.
"This is a huge validation for these
women who are telling their doctors 'something is wrong with
me'," said Shelli Kesler of Stanford University School of
Medicine in California, whose study appears in the Archives of
Kesler said the conventional thinking is
that chemotherapy drugs cannot cross a protective membrane called
the blood-brain barrier that protects the brain from toxins.
And doctors have dismissed women's complaints of brain deficits
after chemotherapy, chalking them up to exaggeration and stress
related to the cancer.
"This shows that when a patient
reports she's struggling with these types of problems, there's a
good chance there has been a brain change," Kesler said.
Her study involved 25 breast cancer
patients who had been treated with chemotherapy, 19 breast cancer
patients who had surgery and other treatments, and 18 healthy women.
All were asked to perform a card-sorting task that involves
problem-solving skills while their brain activity was monitored
through functional magnetic resonance imaging or fMRI.
The women also completed questionnaires to assess their own
As in prior studies of cancer patients, the team saw significant
reductions in activity in two parts of the prefrontal cortex,
including one used for working memory, cognitive control and
But they also found significantly reduced activation of an
additional region of the prefrontal cortex linked with executive
function - the area of the brain needed for planning.
Women in the chemotherapy group were also found to make more errors
on the card-sorting task and take longer to complete it than healthy
women and cancer patients who were not treated with chemotherapy.
While a finding in 25 women seems small, Kesler said it is large for
a brain scan study and points to a need to start identifying which
women who undergo chemotherapy are most vulnerable to these types of
She said future studies should be done in which women are tested
before they undergo chemotherapy to determine the impact of
treatment on brain function.
Women are increasingly surviving their breast cancer, with breast
cancer survivors comprising 22 percent of the nearly 12 million
cancer survivors in the United States, according to the Centers for
Disease Control and Prevention.