The 'Chemobrain' Phenomenon i... Health Article

Chemotherapy is commonly given after other cancer treatments, such as radiation or surgery, to destroy any remaining cancer cells and to help prevent cancer from returning. This type of therapy is called adjuvant therapy. Along with these powerful treatments come complaints from people of "not being able to think clearly" or "having a fuzzy memory." If you have experienced this, it’s not all in your head. It may be real, something that people with cancer have dubbed "chemobrain."

Learning More About Chemobrain

Many of the side effects from chemotherapy are well-known. They include fatigue, nausea and vomiting, and hair loss. But women may not expect a decline in mental function, which includes thinking, memory, language skills, and concentration. It is not clear how or why chemotherapy may affect these skills. Some researchers believe that the drugs directly enter the brain areas that control these functions.

A handful of published studies have reported on chemobrain. A Canadian study published in the Journal of Clinical Oncology was widely publicized. The study looked at women with stage I or II breast cancer. These women either were getting standard-dose adjuvant chemotherapy or had completed a full course of adjuvant chemotherapy one year earlier. Using neuropsychological tests, the researchers compared the women with cancer to a third group of healthy women.

The results found that both groups of women with breast cancer had more moderate to severe cognitive problems than the healthy women in the control group. The study also suggested that the women who had received past treatment continued to have problems with language and visual-motor skills once treatment had ended.

But as with most new areas of research, the study had flaws. Cognitive function is very hard to measure. Finding a good control group to compare with women with breast cancer getting treatment is even more challenging. Julie Olin, MD, wrote a review of chemobrain studies published in the Oncology . Olin pointed out problems in 4 studies, including the Canadian study, 2 Dutch studies, and an earlier American study.

All 4 studies showed at least some impairment in women getting adjuvant chemotherapy compared with women in the control groups. She also notes that none of the women in the studies had cognitive testing before starting chemotherapy--they were only tested afterward. So there was no way to know if the women already had cognitive decline before treatment or if the treatment truly caused it. Studies need to separate cognitive changes due to adjuvant chemotherapy from changes caused by other factors. For example, brain function naturally slows down with age and from lower hormone levels due to menopause or other cancer treatments.

One recent study, published in Cancer, June 2004 addressed some of these concerns. The researchers found that 35% of the women with early-stage breast cancer who had had some type of breast-cancer surgery had lower cognitive scores before they had chemotherapy compared with the average scores of women without breast cancer. This study also measured cognitive function in various groups. These included women who were before or after menopause at the time of the study, those who had taken hormone replacement therapy and those who hadn’t, and those who had various types of breast surgery. But differences among these groups were not statistically significant, which may be due, in part, to the small study sample of 84 women.¹

Another problem is the need for cognitive tests to be made specifically for women with breast cancer. Raine Riggs, PhD, a neuropsychology fellow at the Brown University School of Medicine, explains, "In general, the tests used in these studies were designed for someone with a head injury, stroke, or dementia--something that would make it obvious that the person was impaired. For women with breast cancer, the changes tend to be much more subtle and harder to pick up."

Defining a Good Study

When studying a topic as complex as cognition, researchers must consider things such as these.

• Cognitive function is not as easily recognized as other side effects, such as hair loss or nausea. The symptoms are often vague and subtle. Symptoms may be blamed on depression, fatigue, stress, or anxiety, which are often felt by those newly diagnosed with breast cancer or having new treatment.

• Standard neuropsychological tests for chemobrain are needed. Women should be tested before starting chemotherapy and for many years after it is done. Some brain functions measured might include:

• Attention span

• Visual or verbal memory, which can test a woman’s recall of words or objects presented to her

• Psychomotor speed, which can check how fast and accurately a woman uses her hands for a given task

• A verbal fluency test, in which a woman might be asked to name as many words starting with a given letter as possible within a certain amount of time

• Language skills

Riggs says the last test is for a "tip-of-the-tongue" phenomenon, "where women know the word they want to say but just can’t get it out."

• Changes in estrogen levels and other hormones may affect cognition. Studies suggest that estrogen protects the brain. Breast cancer treatments such as Novaldex (tamoxifen) lower estrogen levels, sometimes causing early menopause. Menopause itself is related to psychological distress and mood changes. Studies need to separate women having chemotherapy alone from those who are also taking tamoxifen or another hormone treatment.

• A good control group needs to be used. Using only healthy women as controls may overemphasize the cognitive problems in treated women. A variety of control groups may be needed. One may include women with breast cancer who are getting radiation and surgery but not chemotherapy. Another might consist of women on tamoxifen, whether using chemotherapy or not, to see if hormone changes play a role.

How to Cope

The impact of chemobrain varies for each woman. Riggs explains, "A loss of memory or concentration can be more disabling for some women than others, depending on their lifestyle and daily use of these functions. For example, if a busy woman has a million things to do every day and experiences these subtle changes, it could really throw her off."

Until more is known, Riggs offers these tips to cope with chemobrain symptoms:

• Avoid distractions. When trying to focus on a task, such as paying the bills or cooking dinner, do so in a calm, quiet environment. Escape background noise from the TV or kids playing nearby.

• Practice difficult tasks. If you need to tackle a complex task, you may want to practice it until it becomes very familiar. "Sometimes, chemobrain makes women feel like they don’t get things as quickly. It may take more time to pick up new information or learn to do that new thing. It’s not that they can’t learn it; it just seems to take longer," says Riggs.

• Check in with your brain. If you feel spaced-out or your mind wanders, Riggs suggests asking yourself every few moments, "What am I doing right now?” or “What am I thinking about?" This keeps you from drifting and helps you refocus.

• Write it down. Keep a journal and a daily planner. Write frequent to-do lists and post reminders for yourself.

• Get organized. Have a specific place for things in the house and office so that you aren’t searching endlessly for them.

• Pump up your mind. Exercise your mind like a muscle. Try crossword puzzles, play sports with your kids, or do any fun thing that keeps you engaged and stimulated. This can also help prevent or control depression and stress.

• Manage stress and get enough sleep and physical activity. High levels of stress hormones decrease mental sharpness, as does a lack of exercise and rest.

• Use mnemonics. Mnemonics are devices like little phrases or catchy songs that help people remember things. For instance, you might use the phrase black-eyed Susan to remember the name of that new coworker with dark eyes.

• Ask for help. Look to your family and friends, or a professional. Let your family know that you are having a hard time focusing and may need help or reminders with certain tasks. If you have serious concerns about your memory or focus, see a neuropsychologist. This is a psychologist who specializes in studying the relationship between the brain and behavior. He or she may be able to give you more personalized advice. Ask your doctor for a referral.