Your Patient's Brain on Drugs -- Cancer Drugs
Your Patient's Brain on Drugs -- Cancer Drugs
Dr. Schapira:There has been an evolution in the way that people refer to this. The original term, "chemo brain," has been improved upon. Can you tell us what your favorite term is for this syndrome, and why?
Dr. Ahles: I think of it as cancer and cancer treatment-related cognitive side effects. The reason is, it has become clear that it is not only chemotherapy that can have this effect. In women with breast cancer, for example, the endocrine therapies, particularly tamoxifen, have been associated with cognitive changes. We don't know whether some of the newer aromatase inhibitors have these cognitive effects because the data are not yet available. In prostate cancer, hormone ablation therapy also can influence cognitive functioning because of its effects on the hormonal milieu.
In women, it is the estrogen, because estrogen is important in the maintenance of memory functioning. In men, it is testosterone. When we started doing more longitudinal studies that included pretreatment assessments, it turned out that 20%-25% of women with breast cancer had lower-than-expected performance on cognitive testing based on their age, education, and occupation prior to beginning treatment. This suggests that there is something about the cancer itself (some type of immune response, for example) that might be the source of these cognitive issues.
There also may be common risk factors for the development of cancer and cognitive decline with age. One hypothesis is that people who are genetically predisposed to having poor DNA repair mechanisms are at higher risk for cancer, but it turns out that they are actually at a higher risk for a number of neurologic disorders that have a significant cognitive component, including Alzheimer disease. There is something about the biology of cancer and the risk for cancer that also seems to be involved in determining who is likely to have longer-term cognitive problems. Having cognitive issues before treatment is itself a risk factor for longer-term cognitive problems.
Time to Discard the "Chemo Brain" Label?
Dr. Schapira:There has been an evolution in the way that people refer to this. The original term, "chemo brain," has been improved upon. Can you tell us what your favorite term is for this syndrome, and why?
Dr. Ahles: I think of it as cancer and cancer treatment-related cognitive side effects. The reason is, it has become clear that it is not only chemotherapy that can have this effect. In women with breast cancer, for example, the endocrine therapies, particularly tamoxifen, have been associated with cognitive changes. We don't know whether some of the newer aromatase inhibitors have these cognitive effects because the data are not yet available. In prostate cancer, hormone ablation therapy also can influence cognitive functioning because of its effects on the hormonal milieu.
In women, it is the estrogen, because estrogen is important in the maintenance of memory functioning. In men, it is testosterone. When we started doing more longitudinal studies that included pretreatment assessments, it turned out that 20%-25% of women with breast cancer had lower-than-expected performance on cognitive testing based on their age, education, and occupation prior to beginning treatment. This suggests that there is something about the cancer itself (some type of immune response, for example) that might be the source of these cognitive issues.
There also may be common risk factors for the development of cancer and cognitive decline with age. One hypothesis is that people who are genetically predisposed to having poor DNA repair mechanisms are at higher risk for cancer, but it turns out that they are actually at a higher risk for a number of neurologic disorders that have a significant cognitive component, including Alzheimer disease. There is something about the biology of cancer and the risk for cancer that also seems to be involved in determining who is likely to have longer-term cognitive problems. Having cognitive issues before treatment is itself a risk factor for longer-term cognitive problems.
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