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'.