Note: small study/also reference blog
abstract posting
Chemotherapy Affects Brain Structure of Breast Cancer Patients
A new study has provided some of the strongest direct evidence to date that chemotherapy has physical effects on areas of the brain that, when altered, could be result in the array of cognitive symptoms that is often called “
chemobrain.” The study was published online August 6 in Breast Cancer Research and Treatment.
In a small study of women with breast cancer, researchers from the Indiana University School of Medicine used MRI scans to show that chemotherapy was associated with a decrease in the density of brain gray matter. The affected areas include those involved in memory and in the ability to process information. Although several other studies have shown similar changes in these areas of the brain, this was the first study to follow women prospectively and to compare scans before and after chemotherapy.
“The alterations in gray matter density observed in the [chemotherapy] group are… consistent with the pattern of cognitive complaints and impairment found in
neurocognitive studies,” wrote Dr. Andrew J. Saykin and colleagues.
The study included 17 women with breast cancer who underwent chemotherapy after surgery, 12 women with breast cancer who did not receive chemotherapy after surgery, and a control group of 18 healthy women. The initial MRI scans, performed shortly after surgery in the participants with cancer, showed no notable differences in gray matter density among the three groups. One month after completion of chemotherapy, however, MRI scans revealed notable decreases in gray matter density in women with breast cancer, as well as changes in gray matter density in women who received surgery only, although the changes for these women were not as great. No changes were seen in women in the control group. After 1 year, women treated with chemotherapy had recovered gray matter losses in some regions, but other deficits persisted.
Exactly how chemotherapy may be causing these changes is unclear, said study co-author Dr. Brenna McDonald. “However, the finding that the changes appear to resolve naturally to some degree in the first year after chemotherapy is completed is a very positive one,” she wrote in an e-mail message. Because of the limited follow-up in the study, she continued, it’s unclear how much further recovery may occur naturally. A number of studies have shown that such cognitive effects can persist for many years, she added. Additional studies are investigating whether other therapies, such as tamoxifen, may have similar effects on brain structure.
For more information on this topic, see: “Delving Into Possible Mechanisms for Chemobrain.”
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