Cognitive function during neoadjuvant chemotherapy for breast cancer: results of a prospective, multicenter, longitudinal study.

Background: It is believed widely that chemotherapy-induced cognitive impairment occurs in a subgroup of patients with breast cancer. However, recent reports have provided no evidence that chemotherapy affects cognition. In this study, the authors questioned whether cognitive compromise in patients with breast cancer is attributable to chemotherapy. In addition, the effects of therapy-induced menopause and of the erythropoiesis-stimulating factor darbepoetin alpha on cognitive performance were assessed.

Methods: A battery of neuropsychological tests was used to assess cognitive performance in 101 patients with breast cancer before neoadjuvant chemotherapy (T1) and toward the end of neoadjuvant chemotherapy (T2) with combined epirubicin, paclitaxel, and cyclophosphamide with concomitant darbepoetin alpha. Repeated-measures multiple analyses of variance and a reliable-change approach were used for statistical analyses.

Results: At T1, the group means ranged below the test norms in 5 of 12 cognitive tests. At T2, multiple analyses of variance (MANOVA) indicated a significant overall improvement in the test results (P<.001). After correcting for practice effects, cognitive decline predominated in 27% of patients, whereas improvement predominated in 28% of patients. Cognitive performance was not related significantly to self-reported cognitive problems, anxiety and depression, menopause, or darbepoetin alpha administration.

Conclusions: Even before chemotherapy, a subgroup of patients with breast cancer showed cognitive compromise that was unrelated to anxiety or depression. During chemotherapy, cognitive function remained stable in most patients, improved in a subgroup, and deteriorated in another subgroup. The deterioration may have been caused by side effects of chemotherapy, but it also may have been related to currently unidentified factors that cause prechemotherapy cognitive compromise. Therapy-induced menopause and darbepoetin alpha did not appear to influence cognition.