Women treated with chemotherapy or radiotherapy performed worse on cognitive functioning tests than women with no history of cancer, according to the results of a 3-year longitudinal study.
“When educating patients about the longer-term impact of treatment on cognitive functioning, health care providers may wish to communicate that such effects may result from radiotherapy with or without chemotherapy,” the researchers wrote.
The study included women with stage 0 to stage II breast cancer who were scheduled to begin to undergo treatment with chemotherapy plus radiotherapy (CT group; n=62) or radiotherapy alone (RT group; n=67). These women were matched with women without cancer. All participants completed neuropsychological assessments 6 months after completing treatment and again 36 months later.
Data indicated there was a significant group X time interaction for the cognitive domain. Although women without cancer showed an improved in this domain over time, no such change was observed for those assigned to chemotherapy or radiotherapy. Although there were no differences between the groups at the first time point, the two treatment groups performed worse by the later follow-up date (P<.05).
Group X time interactions for worsening verbal memory, executive functioning, attention or nonverbal memory domains were not found for women undergoing treatment. However, when the researchers examined for a group effect, they found a significant worsening in executive functioning for women undergoing cancer treatment (P=.006). These women performed worse than women without cancer at both follow-up time points (P<.05), but no difference was found between the CT and the RT groups.
The researchers then performed a subanalysis to determine if hormone therapy was related to these observed changes in cognitive functioning. They found no association.
“Patients who report that cognitive problems are interfering with their daily activities should receive a workup that includes referral to a neuropsychologist who can conduct a systemic evaluation of their cognitive functioning and provide recommendations to address any problems that might be identified,” the researchers wrote