Chemo and Serious Cognitive Impairment
Many of us worry about "chemobrain"--the oft experienced cognitive blunting that may occur while we are on treatment. It also seems to persist for an indefinite period afterwards and disturbs our work to a greater or lesser degree. Some women have no troubles and others feel that their memories are really changed. It is, of course, impossible to truly tease this one apart. What is the impact of the chemotherapy itself vs stress and natural aging and menopause and diminished estrogen? When we talk with our friends who have not had cancer treatment, they often insist that they, too, feel that their memories are less good. Now, we are talking here about the common experience of walking into the kitchen and not remembering why you are there or forgetting a name when you see an acquaintance. We are not talking about serious impairment or, even worse, dementia.
This study from the Journal of Clinical Oncology looked at the impact of chemotherapy on elderly women and their possible increased risk of serious cognitive trouble. The reassuring thing is that none was found.
Relationship Between Chemotherapy Use and Cognitive
Impairments in Older Women With Breast Cancer:
Findings From a Large Population-Based Cohort
Du, Xianglin L. MD, PhD; Xia, Rui MS; Hardy, Dale PhD
Background: Several small scale clinical trials indicated a possible relationship between chemotherapy administration and the increased risk of cognitive impairments in patients with breast cancer, but little information was available from large population-based cohort studies.
Methods: We studied 62,565 women who were diagnosed with stages I-IV breast cancer at age >=65 years from 1991 through 2002 from 16 regions in the Surveillance, Epidemiology and End Results program who were free of cognitive impairments at diagnosis with up to 16 years of follow-up, and also studied 9752 matched cohort based on the propensity of receiving
chemotherapy. The cumulative incidence of cognitive impairments was calculated and the time to event (cognitive impairments) analysis was conducted using Cox hazard regression model.
Results: Overall, patients who received chemotherapy were 8% more likely to have drug induced dementia compared with those without chemotherapy, but that was not statistically significant after adjusting for patient and tumor characteristics (hazard ratio = 1.08, 95%
confidence interval = 0.85-1.37). The risk of developing Alzheimer disease, vascular dementia, or other dementias was significantly lower in patients receiving chemotherapy except for cognitive disorder which was not significantly different between the 2 chemotherapy groups.
The results were somewhat similar in the entire cohort and the matched cohort based on the probability of receiving chemotherapy.
Conclusion: There was no significant association between chemotherapy and the risk of developing drug-induced dementia and unspecified cognitive disorders. The risk of developing Alzheimer disease, vascular dementia, or other dementias was significantly lower
in patients receiving chemotherapy. This study with long-term follow-up did not support the findings that chemotherapy was associated with an increased risk of late stage cognitive impairments.