Two different sides of 'chemobrain': determinants and nondeterminants of self-perceived cognitive dysfunction in a prospective, randomized, multicenter study

Objective: Complaints of cognitive dysfunction are frequent among cancer patients. Many studies have identified neuropsychological compromise associated with cancer and cancer therapy; however, the neuropsychological compromise was not related to self‐reported cognitive dysfunction. In this prospective study, the authors examined if confounding factors masked an underlying association of self‐perceived cognitive function with actual cognitive performance. Determinants of self‐perceived cognitive dysfunction were investigated. Methods: Self‐perceived cognitive function and cognitive performance were assessed before treatment, at the end of treatment, and 1 year after baseline in 101 breast cancer patients randomized to standard versus intensified chemotherapy. Linear mixed‐effects models were applied to test the relationships of performance on neuropsychological tests, patient characteristics, and treatment variables to self‐reported cognitive function. Change of cognitive performance was tested as a predictor of change in self‐reports. Results: Self‐perceived cognitive function deteriorated during chemotherapy and had partially recovered 1 year after diagnosis. The personality trait negative affectivity, current depression, and chemotherapy regimen were consistently related to cognitive self‐reports. No significant associations with performance in any of the 12 cognitive tests emerged. Change of cognitive performance was not reflected in self‐reports of cognitive function. Conclusions: Neuropsychological compromise and self‐perceived cognitive dysfunction are independent phenomena in cancer patients. Generally, cancer‐associated neuropsychological compromise is not noticed by affected patients, but negative affectivity and treatment burden induce pessimistic self‐appraisals of cognitive functioning regardless of the presence of neuropsychological compromise. Clinicians should consider this when determining adequate therapy for patients who complain of ‘chemobrain’. Copyright © 2010 John Wiley & Sons, Ltd.