Update on ChemoBrain
Today is Election Day, and I am reminding you to vote. I hope you share my political views, so that your vote supports, not cancels, mine -- but the important thing is to get to the polls. Each election, as I stand in line early in the morning, I am close to tears as I think about the sacrifices for and the importance of the vote. It is an enormous responsibility and a privilege.
This is an excellent review article from the Journal of Clinical Oncology about the state of science related to cognitive change/chemobrain. There has been increasing evidence over the past 10 to 15 years that chemotherapy can diminish cognitive function and, in some cases, have a long and damaging effect on educational, professional, and personal goals.
As I have said before, most of us do not have serious difficulties and figure out how to compensate or work around any small lapses. There are people, however, who do have major troubles, and it is most encouraging and distressing that there is now enough evidence to force attention to be paid to the problem.
Here are excerpts, as the full article is only available to subscribers:
Cancer- and Cancer Treatment-Associated Cognitive Change: An Update on the State of the Science
Tim A. Ahles, James C. Root, and Elizabeth L. Ryan
Cognitive changes associated with cancer and cancer treatments have become an increasing concern. Using breast cancer as the prototype, we reviewed the research from neuropsychological, imaging, genetic, and animal studies that have examined pre- and post-treatment cognitive change. An impressive body of research supports the contention that a subgroup of patients is vulnerable to post-treatment cognitive problems.
We also propose that models of aging may be a useful conceptual framework for guiding research in this area and suggest that a useful perspective may be viewing cognitive change in patients with cancer within the context of factors that influence the trajectory of normal aging.
Cognitive changes associated with treatments for CNS and pediatric cancers have long been recognized. However, over the last 15 to 20 years, increasing evidence has suggested that treatments for non-CNS tumors can have both acute and long-term effects on cognitive functioning, which can affect educational and occupational goalsandquality of life.
Understanding these cognitive changes and the impact on survivors' functioning is critical, because hundreds of thousands of patients are treated worldwide each year, and the number of long-term survivors who may have to cope with these cognitive changes is growing dramatically. This review focuses on cognitive changes associated with adjuvant treatment for breast cancer as an example of the emerging findings in this field. Furthermore, we will explore the value of viewing this literature.
Few studies designed to evaluate interventions to treat cognitive changes have been reported. In terms of medication management of cognitive deficits, two studies have found support for the efficacy of modafinil, a psychostimulant, in improving memory and attention and reducing fatigue. Cognitive rehabilitation approaches are also being developed, with initial reports of positive results.71 A recent review of factors associated with prevention of cognitive decline with aging reported evidence for cognitive training, physical exercise, and possibly diet as efficacious interventions.72 These data suggest the value of testing exercise and dietary interventions to preserve cognitive function in cancer survivors.
A legitimate question is the extent to which the breast cancer studies are generalizable to other types of cancers and treatment regimens. Research examining treatment-related cognitive change in other cancers is difficult to evaluate, because there are generally fewer studies. However, evidence for treatment-related cognitive changes has been found for patients with various tumors, including lymphoma, leukemia, ovarian, and prostate (hormone ablation) cancers, although negative studies have been reported. On the other hand, studies of patients with testicular cancer suggest that cognitive deficits can be identified on self-report measures of cognitive functioning, not on objective neuropsychological testing. Interestingly, the chemotherapy agents included in treatment regimens for testicular cancer (cisplatin, etoposide, bleomycin) have been implicated in cognitive change in other cancers. Therefore, questions remain as to whether there are aspects of the treatment regimen (eg, dose, timing) or the biology of the disease that are responsible for the lack of results on neurocognitive testing. Alternatively, patients with testicular cancer tend to be younger than most other cohorts studied. Consistent with the discussion of models of aging, it may be that younger patients have more physical and cognitive reserve, which allows them to maintain performance on neuropsychological testing. However, children treated for non-CNS cancers and adult survivors of these childhood cancers can experience persistent cognitive changes78; therefore, there may be a curvilinear relationship with age, in that younger and older patients with cancer are more vulnerable to cognitive change, whereas younger to middle-aged adults may be more resilient. Clearly, additional research is necessary to test this hypothesis.
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