Many women treated with chemotherapy for breast cancer say they have a hard time remembering things, thinking, and concentrating. Doctors call these skills cognitive function.
Doctors believe that some women are more likely to have cognitive problems after chemotherapy. To help figure out who these women are, a small study wanted to see if being older and having lower cognitive reserve levels increase the risk of cognitive problems during and after chemotherapy.
Psychologists use the term "cognitive reserve" to describe how resilient a person's brain might be to certain factors, including:
- cancer treatment
- lack of sleep
that could cause a decline in cognitive function.
The results of this study suggest that being older and having lower cognitive reserve levels are linked to cognitive problems during and after chemotherapy.
Some women being treated for breast cancer, especially some women getting chemotherapy, have cognitive problems, including:
- learning new tasks
- remembering names
- paying attention and concentrating
- coming up with the right words
- remembering where things are
Some people call these problems "chemobrain." Research has shown that these problems are likely to be caused by chemotherapy in many women.
To see if age and cognitive reserve were related to any chemotherapy-caused cognitive problems, researchers tested cognitive skills in three groups of women:
- 60 women diagnosed with early-stage breast cancer who got chemotherapy (average age about 52)
- Some of these women also took hormonal therapy medicine: 34 women took tamoxifen and 5 took Arimidex (chemical name: anastrozole)
- 72 women diagnosed with early-stage breast cancer who didn't have chemotherapy (average age about 57)
- Some of these women took hormonal therapy medicine: 39 of these women took tamoxifen, 7 took Arimidex, and 3 took Evista (raloxifene)
- 45 women who weren't diagnosed with breast cancer but otherwise were similar to the other two groups of women (average age about 53); these women were the control group
Women who got chemotherapy had several cognitive function tests before, during, and after treatment. Women who didn't get chemotherapy but did take hormonal therapy medicine had the tests before and during treatment. The test results of women who were treated for breast cancer were compared to the test results of the healthy women.
The researchers found that cognitive problems in women getting chemotherapy seemed to be linked to being older. Older women who got chemotherapy had significant declines in:
- how fast they processed information (processing speed)
- how well they could use and understand words and language (verbal ability)
- how well they could remember words (verbal memory) and images (visual memory)
- how well they could sort things (sorting assessment)
- how well their memories worked (able to follow complex verbal instructions, for example)
Older women who got chemotherapy also were easily distracted.
To measure cognitive reserve in the women before they started any treatment, the researchers used a test called the WRAT-3 (Wide Range Achievement Test, edition 3). Older women in the study had lower cognitive reserve levels than younger women before treatment started. Women with lower cognitive reserve levels were more likely to have cognitive problems during chemotherapy.
The researchers also found that about 20% to 30% of the women diagnosed with breast cancer had cognitive reserve levels that were below average BEFORE treatment. This interesting and surprising result suggests that breast cancer and/or the experience and stress of being diagnosed may reduce cognitive function all by itself.
Still, one positive result was that many of the women who got chemotherapy didn't have cognitive problems. And most women who do have memory and thinking problems during breast cancer treatment recover and can think clearly after treatment is done.
If you're having thinking and memory problems related to breast cancer treatment, there are things you can do to help yourself. In October 2008 Breastcancer.org held an Ask-the-Expert Online Conference on chemobrain. You might want to check out the transcript to read about other women's questions and the answers from Breastcancer.org medical experts. You'll find tips on:
- managing memory challenges
- keeping your mind alert
- getting more and better quality sleep
- staying safe when you're not so alert