Women with breast cancer may experience problems with tasks like finding the right words to convey a message or following directions to a destination more than six months after chemotherapy treatment ends, a recent analysis finds. While these verbal and visuospatial issues may be concerning, no other cognitive functions, such as attention, focus, memory or dexterity, were significantly affected after treatment ended.
Reason for the Study
For many years, women have reported symptoms of chemobrain, problems with thinking or memory associated with chemotherapy treatment.
Past research suggests chemobrain is apparent during active treatment, but few have studied its long-term effects. Investigators at the Moffitt Cancer Center in Tampa, Fla., analyzed several previously published papers to explore whether chemobrain symptoms continue after treatment ends and what those symptoms might be.
Structure of the Analysis
This study is a meta-analysis, in which researchers collect data and results from several existing studies and combine them to learn about the larger or longer-term effects of the treatment being studied.
The researchers gathered 17 studies from 1998 to 2011 that reported on cognitive issues of people with breast cancer. All studies compared participants at least six months out of standard chemotherapy treatment to people with cancer who did not receive chemotherapy, people without cancer, a pre-chemotherapy baseline, or a combination of the three. A baseline is a measure of a person’s ability to do a task before they were treated, to compare to their ability after treatment.
In total, 807 participants received chemotherapy, 391 had surgery, radiation or hormonal therapy and 291 did not have cancer. The average age of participants was 52.3 years; the average time since chemotherapy treatment ended was 2.9 years.
Participants had widespread symptoms of chemobrain during treatment, this analysis found. But more than six months after treatment ended, verbal and visuospatial ability were the only skills still affected.
Other functions analyzed that did not continue to be affected by chemotherapy were attention, a person’s ability to focus on one topic, executive functioning, a person’s ability to plan and carry out goals, information processing, the ability to take in and react to information, motor speed, a person’s dexterity, and verbal and visual memory, the ability to recognize word lists or images.
Age, education, time since chemotherapy ended, and treatment with hormonal therapy or tamoxifen did not have a significant impact.
Researchers say these findings show that symptoms of chemobrain six months after treatment are mild when compared with symptoms during active treatment or during other cancer therapies.
This study offers insight, but more research is needed. Most participants were middle-aged and highly educated, so they were more likely to perform better on tests than peers who were older or less educated. The results do not reflect the experiences of people with metastatic breast cancer.
Also, the results are highly dependent on the groups compared. For example, people treated with chemotherapy performed significantly worse on verbal ability than people without cancer, but not worse than their own baselines or people treated with local therapies. Using this study design may ignore other factors that can impact cognitive function, such as stress and fatigue.
What This Means for You
Chemobrain symptoms may be frustrating and have a significant impact on your daily life during treatment, but these new findings suggest most symptoms will disappear in the first half-year after you complete chemotherapy, on average.
Researchers did note that each person’s experience may be very different, with some reporting no symptoms and some reporting more severe symptoms. They suggest doctors refer anyone with persistent symptoms that interfere with everyday function to a neuropsychologist, a doctor that studies brain function and behavior. To learn more, read LBBC’s resources on chemobrain.
Jim, Heather S.L., Phillips, Kristin M., et al : Meta-Analysis of Cognitive Functioning in Breast Cancer Survivors Previously Treated with Standard-Dose Chemotherapy. J Clin Oncol (October 2012) 30 (29): 3578-87.