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 α 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 α. 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 α 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 α did not appear to influence cognition. Cancer 2007. © 2007 American Cancer Society.

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 r 2010 John Wiley & Sons, Ltd.Keywords: oncology; cancer; cognition disorders; adverse effects; neuropsychological tests; antineoplastic combined chemotherapy protocols ObjectiveAfter cytostatic treatment, many cancer patients complain about cognitive side effects such as attention and memory problems. As a result of these reports, cognitive function in cancer patients has been investigated in a growing number of studies and the existence of chemotherapy-associated cognitive compromise has indeed been confirmed by many of them. However, with few exceptions, cognitive compromise as assessed by neuropsychological testing appeared to be unrelated to self-reported cognitive dysfunction. The divergence of objectively assessed cognitive function and subjective reports has been found pretreatment [1][2][3], as well as during or after chemotherapy [4][5][6][7][8][9][10][11][12][13][14][15] or hormonal therapy [16] in patients with breast cancer [1,2,[5][6][7][8][9][10][12][13][14]16], testicular cancer [4], lymphoma [12,15], and in bone marrow ...

Largely irrespective of chemotherapy, breast cancer patients may encounter very subtle cognitive dysfunction, part of which is mediated by cancer-related post-traumatic stress. Further factors other than treatment side effects remain to be investigated.

BACKGROUND. It is suspected that estrogen depletion resulting from treatment may contribute to cognitive compromise in patients with breast cancer. However, the evidence for estrogen effects on cognition is inconclusive, and the consequences of hormonal changes for cognitive function in patients with cancer rarely have been investigated. In this study, the authors investigated the effects of treatment‐induced menopause and antiestrogen therapy with tamoxifen and aromatase inhibitors (AIs) on cognitive function. METHODS. Cognitive performance was assessed in 101 patients with breast cancer before the start of cancer therapy (T1), toward the end of neoadjuvant chemotherapy (T2), and 1 year after baseline (T3) using 12 cognitive tests. Menopause occurred in a subgroup of patients, and an overlapping subgroup started antiestrogen therapy with tamoxifen or AIs. Linear mixed‐effects models that made it possible to determine effects at group levels and individual levels simultaneously were used for statistical analysis. RESULTS. At the group level, a significant favorable effect of induced menopause emerged in a test of executive function (P = .0035). Two additional group‐level effects of induced menopause, both favorable, and 2 individual‐level effects that were positive in some patients and negative in others were not significant when multiple testing was taken into account. No significant effects of tamoxifen or AIs on cognitive function were observed. CONCLUSIONS. Hormonal changes did not appear to contribute to cognitive compromise in patients with breast cancer during the first year after diagnosis. Antiestrogen treatment with tamoxifen or AIs did not affect cognition, and the effects of induced menopause were more likely to be favorable. However, the possibility that some cognitive decline occurs in individual patients could not be excluded. Cancer 2008. © 2008 American Cancer Society.

Prior to any treatment, breast cancer patients may show limited cognitive impairment that is apparently largely caused by cancer-related post-traumatic stress.