Forgetfulness Can Be a Side Effect of Cancer Treatment
Medically reviewed by C.H. Weaver M.D. Medical Editor 8/2018
Chemotherapy has been associated with causing cognitive deficits, such as forgetfulness and an inability to concentrate. At this time, there are no proven treatments for cognitive deficits associated with chemotherapy. However, the best way to deal with this unpleasant side effect of chemotherapy is to take steps to minimize the impact of forgetfulness and difficulty concentrating on your daily life.
What are cognitive deficits?
Cognitive deficits are problems with thinking, learning and memory. If you have cognitive deficits, you may be forgetful or have difficulty concentrating.
What causes forgetfulness and an inability to concentrate?
Research has demonstrated that chemotherapy can have a negative impact on cognitive functioning. Long-term (5-year) cancer survivors who had received chemotherapy scored significantly lower on neuropsychologic tests, particularly in the area of verbal memory, compared with those treated with local therapy only (i.e. surgery). The patients who received chemotherapy also reported greater problems with working memory and were more likely to score among the lowest on the Neuropsychological Performance Index. Furthermore, some survivors may experience long-term cognitive deficits associated with systemic chemotherapy.
The way in which chemotherapy causes cognitive deficits is not clear at this time. It may be related to anemia or a direct effect of chemotherapy on brain function. Your problems with memory and concentration may improve once you complete your chemotherapy; but there is also a possibility that these will be long-term problems.
Other factors that contribute to memory and concentration problems include:
- Low blood counts
- Mental and emotional stress of coping with cancer
Can cognitive deficits be treated?
At this time, there are no proven treatments for cognitive deficits associated with chemotherapy. However, research is ongoing to find a treatment that may help relieve this side effect.
Erythropoietin, a chemical produced by the body that stimulates the production of red blood cells, may protect cells in the brain from the damaging effects of chemotherapy. Researchers from the US Oncology trials group studied the effect of erythropoietin compared to placebo (sugar pill) on cognitive function in 88 patients receiving chemotherapy. While there were no differences in cognitive function at 6 months after chemotherapy, both groups experienced improvement in performance compared to the first time they took the test. The researchers think this may be due to a practice effect, which means the participants may have learned from the first time they were tested.
Some researchers have also suggested that the herbs Gingko biloba and ginseng can improve cognition and mood and the North Central Cancer Treatment Group (NCCTG) is conducting a randomized placebo-controlled trial testing the effects of Gingko biloba on cognitive function in patients with early-stage breast cancer receiving adjuvant chemotherapy.
What else can I do?
Problems with memory and concentration can be very frustrating. While there may not be confirmed treatments at this time, there are things you can do to reduce the impact these problems have on your everyday life. Try these tips:
- Minimize distractions when you need to complete tasks that require concentration.
- Use a daily organizer to help you remember appointments.
- Keep a journal of daily events and activities.
- Carry a notebook, and use it to write down important information that you want to remember.
- Get plenty of sleep.
- Exercise daily.
- Manage stress.
 Ahles TA, Saykin AJ, Furstenberg CT, Cole B, et al. Neuropsychologic Impact of Standard-Dose Systemic Chemotherapy in Long-Term Survivors of Breast Cancer and Lymphoma. Journal of Clinical Oncology2002;20,(2):485-493.
 O’Shaughnessy J, Vukelja S, Savin M, et al. Impact of epoetin alfa on cognitive function, asthenia, and quality of life in women with breast cancer receiving adjuvant or neoadjuvant chemotherapy: Analysis of 6-month follow-up data. Breast Cancer Res Treat 2002;76:550. (abstr).