New approaches to understand cognitive changes associated with chemotherapy for non-central nervous system tumors.

Context: Researchers have described a constellation of cognitive deficits (e.g., impairments in executive functions, working memory, attention, and information-processing speed) associated with cancer treatment, and specifically chemotherapy, for non-central nervous system tumors. However, findings have been inconsistent, largely because of measurement and study design issues.

Objectives: To propose ways for researchers to more clearly delineate and characterize the mild cognitive deficits and related outcomes that appear to affect a subset of cancer patients and suggest methods to make more effective use of the existing data to understand risk factors for impaired neuropsychological functioning.

Methods: We examined the literature on the relationship between chemotherapy and cognitive impairment, as well as related literature on neuropsychological measurement, structural and functional neuroimaging, alternative measures of health outcomes, and integrative data analysis.

Results: A more comprehensive picture of cognitive functioning might be obtained by incorporating nontraditional ecological measures, self-reports, computational modeling, new neuroimaging methods, and markers of occupational functioning. Case-control and integrative data analytic techniques potentially could leverage existing data to identify risk factors for cognitive dysfunction and test hypotheses about the etiology of these effects.

Conclusion: There is a need to apply new research approaches to understand the real-world functional implications of the cognitive side effects of chemotherapy to develop and implement strategies to minimize and remediate these effects before, during, and after cancer treatment.