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For many years cancer survivors have worried about, joked
about, and been frustrated with the mental cloudiness they notice
before, during, and after chemotherapy. We don't know its exact cause
but this mental fog is commonly called "chemo brain." Patients have
noticed this mental fog for some time, but only recently have studies
been done that could start to explain it.
Research has shown that some cancer drugs can, indeed, cause
changes in the brain. Imaging tests have shown that after chemotherapy,
some patients have smaller brain size in the parts of the brain that
deal with memory, planning, putting thoughts into action, monitoring
thought processes and behavior, and inhibition.
Some people report having these symptoms even before they
start treatment. Others report it even though they have not had
chemotherapy. Still others notice the problem when they are getting
hormonal treatments. So the term "chemo brain" may not be completely
accurate, but it is the name that most people call it right now.
Though the brain usually recovers over time, the sometimes
vague yet distressing mental changes cancer patients notice are real,
not imagined. They affect daily activities and need to be researched
further.
What is chemo brain?
Here are just a few examples of what patients call chemo
brain:
- forgetting things that they usually have no trouble
recalling-- memory lapses
- trouble concentrating--they can't focus on the task at hand
- trouble remembering details like names, dates, and
sometimes larger events
- trouble multi-tasking, like answering the phone while
cooking, without losing track of one of them-- less ability to do more
than one thing at a time
- taking longer to finish things --slower thinking and
processing.
- trouble remembering common words--can't finish a sentence
because you can't find the right words
For some people these effects happen quickly and only last a
short time, while others have mild, long-term mental changes. Usually
the changes that patients notice are very subtle, and others may not
notice any at all. Still, the people who have problems are well aware
of the differences in their thinking. Many people do not tell their
healthcare team about this problem until it affects their everyday
life.
Doctors and researchers call chemo brain "mild cognitive
impairment" and define it as being unable to remember certain things
and having trouble finishing certain tasks or learning new skills.
Is chemo brain real?
Yes, chemo brain is
real, but its cause is unknown. How often it happens, what may trigger
it, or what can be done to prevent it, is also unknown.
Pictures of the brain have shown changes in the brain activity
of breast cancer survivors treated with chemotherapy when compared with
those who were not treated with chemotherapy. These changes continued
to show up on scans 5 to 10 years after treatment stopped. Chemo brain
could be caused by any one or a combination of the following factors:
- the cancer itself
- chemotherapy drugs
- other drugs used as part of treatment (such as anti-nausea
or pain medicines)
- patient age
- stress
- low blood counts
- depression
- fatigue
- hormone changes
What is known is that chemo brain is a real problem that
affects both men and women. Even though chemotherapy does not seem to
be the only cause, a low estimate is that 20% to 30% of people who get
chemotherapy will have chemo brain.
What can I do to manage chemo brain?
Day-to-day coping
Experts have been studying memory for a long time and there
are many resources to help you sharpen your mental abilities and manage
the problems that may come with chemo brain. Some things that you can
do include the following:
- Use a detailed daily planner. Keeping everything in one
place makes it easier to find the reminders you may need. Serious
planner users keep track of their appointments and schedules, "to do"
lists, important birthdays and anniversaries, phone numbers and
addresses, meeting notes, and even movies they'd like to see or books
they'd like to read.
- Exercise your brain. Take a class, do word puzzles, or
learn a new language.
- Get enough rest and sleep.
- Exercise your body. Regular physical activity is not only
good for your body, but also improves your mood, makes you feel more
alert, and decreases fatigue.
- Eat your veggies. Studies have shown that eating more
vegetables can help you maintain brain power.
- Set up and follow routines. Pick a certain place for
commonly lost objects and put them there each time. Try to keep the
same daily schedule.
- Don't try to multi-task. Focus on one thing at a time.
- Track your memory problems. Keep a diary of when you notice
problems and the events that are going on at the time. (You might track
this in your planner.) Medicines taken, time of day, and the situation
you are in may help you figure out what affects your memory. Keeping
track of when the problems are most noticeable can also help you
prepare by not planning important conversations or appointments during
those times.
- Try not to focus so much on how much these symptoms are
bothering you. Accepting the problem will help you deal with it. As
many patients have noted, being able to laugh about things you can't
control can help you cope. And remember, you notice your problems much
more than others do. Sometimes we all have to laugh about forgetting to
take the carefully composed grocery list with us to the store.
Telling others
Another thing you can do to better manage chemo brain is tell
family, friends, and your healthcare team about it. Let them know what
you are going through. You will probably feel relieved once you tell
people about the problems you have sometimes with your memory or
thinking.
You are not stupid or crazy; you just have a side effect that
you have to learn to manage. Even though this is not a change that is
easy to see, like hair loss or skin changes, your family and friends
may have noticed some things and may even have some helpful
suggestions. For example, your partner may notice that when you are
rushed, you have more trouble finding things. Tell them what they can
do to help. Getting support and understanding can help you relax and
make it easier for you to focus and process information.
Many large hospitals and cancer centers have neurologists,
psychoneurologists, and psychologists who are experts at testing brain
function, including the symptoms of chemo brain. Testing can help
specialists find the extent of your symptoms and then suggest the best
mental exercises for your problems. You may want to ask for a referral
to one of these specialists who can help you learn the scope of your
problem and work with you on ways to manage your memory or thinking
problems.
Can chemo brain be prevented?
The cause of chemo brain is unknown and at this time there is
no way to prevent it. It seems to happen more commonly with high doses
of chemotherapy. But because chemo brain is usually mild and most often
goes away over time, proven and effective chemotherapy plans should not
be changed to try to prevent this side effect.
What is being done about chemo brain?
Now that chemo brain is recognized as a link to cancer and its
treatment, studies are being done to learn more about it. Some studies
are looking to find out which chemotherapy drugs and other treatments
are more closely linked to chemo brain. Researchers are also looking at
possible ways to prevent chemo brain as well as ways to help survivors
who are still having trouble thinking. Researchers are studying other
aspects of cancer treatment that may lead to long-term mental changes,
too. For example, they are looking at the types and doses of
chemotherapy the patients have received and genetic differences among
individuals to see if these factors are linked to a higher risk of
chemo brain.
Future directions
Recent studies have shown clear evidence of nerve damage from
at least some forms of chemotherapy. But studies of the effects of
chemotherapy drugs on brain cells are still rare. This area is a focus
of ongoing chemo brain research because scientists must find out which
nerve cells or brain cells are at risk during cancer treatment to
develop ways to reduce damage, save cognitive function, and maintain
the quality of life in long-term survivors. So far, early studies in
the lab and in animals suggest that certain chemotherapy drugs may harm
some nerve cells even after the drug is stopped. But more research is
needed to see if this happens in humans, too.
There is more concern about chemo brain now because of recent
cancer treatment study results that favor the use of more aggressive
and high-dose drug schedules. There are also newer targeted drugs that
affect the pathways that are part of nerve cell formation and stem cell
function, which heightens the concern. Discovering which nerve cells
are affected may also let scientists test new drugs for this side
effect when they are being developed.
Cancer experts also are looking into treatment options that
may protect the brain from chemo side effects. Research is being done
on targeted drugs that focus on the cancer cells and spare normal,
healthy cells, such as brain and nerve cells.
Researchers are also looking at medicines that are now used
for problems like depression, attention-deficit hyperactivity disorder,
and dementia as possible treatments for chemo brain.
Genetic differences that may make some people more likely to
have symptoms of chemo brain are being explored, too. One particular
gene, called APOE, is being looked at closely. Research has shown that
a version of this gene, E4, is linked to Alzheimer disease. When E4 is
present, there is an increased chance of cognitive (thinking) problems
after traumatic brain injury. Studies are being done to find out if
people who have the E4 gene who get chemotherapy have a higher risk of
developing long-term chemo brain.
Recognizing chemo brain as a treatment side effect was the
first step. Doctors and researchers are now trying to measure it -- how
exactly does it affect patients' brains and cause changes? This
information will hopefully help them find ways to not only treat chemo
brain, but prevent it.
Additional resources
More information from your American Cancer
Society
We have selected some related information that may also be
helpful to you. These materials may be ordered from our toll-free
number.
National organizations and Web sites*
In addition to the American Cancer Society, other sources of
patient information and support include:
American Psychological Association (APA)
Toll-free number: 1- 800-374-2721
Web site: www.apa.org
American Psychosocial Oncology Society (APOS)
Toll-free number: 1-866-276-7443
Web site: www.apos-society.org
*Inclusion on
this list does not imply endorsement by the American Cancer Society.
No matter who you are, we can help. Contact us anytime, day or
night, for information and support. Call us at 1-800-ACS-2345 or
visit www.cancer.org.
References
Ahles TA, Saykin AJ, Noll WW, et al. The relationship of APOE
genotype to neuropsychological performance in long-term cancer
survivors treated with standard dose chemotherapy. Psycho-Oncology.
2003;12:612-619.
Chemobrain: When cancer treatment disrupts your thinking and
memory. Available at:
www.mayoclinic.com/health/cancer-treatment/CA00044. Accessed May 9,
2008.
Dietrich J, Han R, Yang Y, Mayer-Pröschel M, Noble M.
CNS progenitor cells and oligodendrocytes are targets of
chemotherapeutic agents in vitro and in vivo. Journal of Biology.
2006;5:22.
Ferguson RJ, Ahles TA, Saykin AJ, McDonald BC, et al.
Cognitive-behavioral management of chemotherapy-related cognitive
change. Psychooncology.
2007 Aug;16(8):772-777.
Han R, Yang YM, Dietrich J, Luebke A, et al. Systemic
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Hede, K. Chemobrain is real but may need new name. J Natl Cancer Inst 2008;100(3):
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Inagaki M, Yoshikawa E, Matsuoka Y, et al. Smaller Regional
Volumes of Brain Gray and White Matter Demonstrated in Breast Cancer
Survivors Exposed to Adjuvant Chemotherapy. Cancer.
2007;109:146-156.
Morris MC, Evans DA, Tangney CC, Bienias JL, Wilson RS.
Associations of vegetable and fruit consumption with age-related
cognitive change. Neurology.
2006;67:1370-1376.
Silverman DH, Dy CJ, Castellon SA, et al. Altered
frontocortical, cerebellar, and basal ganglia activity in
adjuvant-treated breast cancer survivors 5-10 years after chemotherapy.
Breast Cancer Res Treat.
2006. Available at:
http://portfolio.psybrain.net/uploads/Psycho-onco/Silverman2006.pdf.
Accessed May 9, 2008.
Vardy J, Rourke S, Tannock IF. Evaluation of cognitive
function associated with chemotherapy: a review of published studies
and recommendations for future research. J Clin Oncol. 2007
Jun 10;25(17):2455-2463.
Last Medical Review: 06/13/2008
Last Revised: 06/13/2008
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