The research focused on the brain scans of 17 women with breast cancer treated with chemotherapy after surgery, 12 women with breast cancer who did not have chemotherapy after surgery, and 18 women without breast cancer.
The negative effects of chemotherapy on cognition, referred to as “chemo-brain,” are well-known by physicians and researchers. However, this study is the first to use brain imaging on women who have breast cancer, both before and after treatment, showing that chemotherapy affects the gray matter of the brain right alongside a decline in cognition.
“This is the first prospective study,” said Andrew Saykin, Psy.D., director of the Indiana University Center for Neuroimaging and a professor at the Indiana University School of Medicine.
“These analyses suggest an anatomic basis for the cognitive complaints and performance changes seen in patients. Memory and executive functions like multi-tasking and processing speed are the most typically affected functions and these are handled by the brain regions where we detected gray matter changes.”
Dr. Saykin and his team analyzed structural MRI scans of the brain taken on both patients with breast cancer as well as healthy controls. The scans were done after surgery, but before radiation or chemotherapy, so the researchers could have a baseline. Scans were then repeated one month and one year after chemotherapy was finished.
According to the scans, changes in gray matter were most obvious in the areas of the brain associated with the cognitive dysfunction experienced by patients during and shortly after chemotherapy. The good news is that, in most women, gray matter density improved a year after chemotherapy ended.
Dr. Saykin said that, for many patients, the effects are subtle. For some, however, gray matter changes can be more significant. For example, in a relatively rare number of chemotherapy patients — usually middle-aged women — the changes in the brain are so great that they are unable to return to work. Most women, however, will still be able to work and multitask, but may find it more difficult to do so.
“We hope there will be more prospective studies to follow so that the cause of these changes in cancer patients can be better understood,” Dr. Saykin said.
Dr. Saykin and his team began their research at Dartmouth Medical School and finished the data analyses at Indiana University. A new, independent study is now underway at the Indiana University Simon Cancer Center to affirm and continue the research of this problem affecting many chemotherapy patients.
The findings can be found in the October 2010 edition of Breast Cancer Research and Treatment.