Shilling V, Jenkins V, Fallowfield L, Howell A.
The effects of oestrogens and anti-oestrogens on cognition.

Breast. 2001 Dec;10(6):484-91.
PMID: 14965628 [PubMed]

Recent research suggests that oestrogen may play an important role in cognition. Epidemiological and experimental studies of hormone replacement therapy in post-menopausal women suggest that oestrogen may be important to verbal memory in particular, as well as other cognitive functions such as attention and processing speed. Some studies have also suggested that HRT may have a beneficial effect for Alzheimer’s disease, both in the prevention or delay of onset and that it is also of therapeutic benefit to patients in whom the disease is established. The use of selective oestrogen receptor modulators (SERMs) and other hormonal therapies for the treatment of breast cancer is common, yet few studies have examined the possible cognitive effects of this form of treatment. Several studies have shown cognitive decline in women receiving treatment for breast cancer, but the focus has been on the effects of chemotherapy. Further confusion has resulted from the diverse methodologies used in the existing literature. A pilot study to develop a suitable cognitive battery of tests for the evaluation of cognitive function in women receiving hormonal therapy for the treatment or prevention of breast cancer is introduced.

bulletCRC Psychosocial Oncology Group, University of Sussex, UK.
Bender CM, Paraska KK, Sereika SM, Ryan CM, Berga SL.
Cognitive function and reproductive hormones in adjuvant therapy for breast cancer: a critical review.

J Pain Symptom Manage. 2001 May;21(5):407-24. Review.
PMID: 11369162 [PubMed – indexed for MEDLINE]

Deterioration in cognitive function-particularly learning, memory, and attention-has been reported by women with breast cancer who receive adjuvant chemotherapy. Deficits in cognitive function reported by women with breast cancer are similar to those experienced by women as a consequence of natural or surgical menopause. The basis of these deteriorations may include reductions in reproductive hormone levels, particularly estrogens and progesterones, that occur as a result of adjuvant chemotherapy. This paper critically examines the literature related to the impact of adjuvant chemotherapy and reproductive hormone changes on cognitive function in women with breast cancer and suggests direction for future research in this area. The paper proposes a framework for investigation of the problem and discusses the challenges associated with the conduct of this research.

bulletSchool of Nursing, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Olin JJ.
Cognitive function after systemic therapy for breast cancer.

Oncology (Williston Park). 2001 May;15(5):613-8; discussion 618, 621-4. Review.
PMID: 11396356 [PubMed – indexed for MEDLINE]

An underinvestigated area of breast cancer survivorship involves the possible impairment of cognitive function following adjuvant chemohormonal therapy. Numerous reports of disturbing and disruptive changes in short- and long-term memory, attention span, concentration, and language skills have been made by breast cancer patients who have received chemotherapy. This article reviews the four published studies that have documented cognitive dysfunction following adjuvant chemohormonal therapies commonly used in breast cancer. The studies describe a subset of approximately one-third of participants who experienced long-term cognitive impairment. Patient- and treatment-related factors that may influence cognitive function are outlined. The impact of these cognitive impairments on the individual breast cancer survivor’s quality of life is discussed, as is the potential overall impact of this research on future adjuvant therapy. The need for a prospective longitudinal study documenting the neuropsychological sequelae of adjuvant chemohormonal therapy is emphasized.

bulletUniversity of Vermont College of Medicine, Burlington, Vermont, USA.
Ahles TA, Saykin A.
Cognitive effects of standard-dose chemotherapy in patients with cancer.

Cancer Invest. 2001;19(8):812-20. Review.
PMID: 11768035 [PubMed – indexed for MEDLINE]

Adult cancer survivors have reported experiencing persistent changes in cognitive function following treatment with chemotherapy. Increasing evidence supports the hypothesis that standard-dose chemotherapy can produce cognitive deficits in a subgroup of adult cancer survivors. Although these cognitive changes tend to be subtle deficits in memory, concentration, and the ability to remain focused or organized, these alterations in cognitive ability can have a significant impact on patients’ quality of life generally, and on meeting career and educational goals specifically. This manuscript reviews the literature relevant to the cognitive impact of standard-dose chemotherapy in adults, outlines methodological issues related to the study of cognitive functioning in people with cancer, and discusses future directions for research in this area.

bulletDepartment of Psychiatry and Center for Psycho-Oncology Research, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA.
Schagen SB, Hamburger HL, Muller MJ, Boogerd W, van Dam FS.
Neurophysiological evaluation of late effects of adjuvant high-dose chemotherapy on cognitive function.

J Neurooncol. 2001 Jan;51(2):159-65.
PMID: 11386413 [PubMed – indexed for MEDLINE]

OBJECTIVES: To evaluate late neurotoxicity of adjuvant high-dose (HD) chemotherapy versus standard-dose (SD) chemotherapy by event-related potentials (ERP) and quantitative electroencephalography (qEEG). PATIENTS AND METHODS: From a randomized study in high-risk breast cancer patients on the efficacy of high-dose versus standard-dose adjuvant chemotherapy, late effects on cognitive functioning were analyzed by neuropsychological tests. Cognitive impairment was found in 32% of the HD group, 17% of the SD group and in 9% of a control group of stage I breast cancer patients not treated with chemotherapy. In 17 consecutive patients in the HD group and 16 consecutive patients in the SD group neurophysiological tests were performed, consisting of P300 and qEEG. Results of patients treated with chemotherapy were compared with results of 14 control patients not treated with chemotherapy. All patients were tested two years after treatment. RESULTS: Asymmetry of the alpha rhythm of > or =0.5 Hz was found in 7 HD patients, 2 SD patients and in none of the control patients (p = 0.01). No differences were found between the groups with regard to frequency of alpha rhythm, alpha blocking and latency of P300. No correlation was found between neurophysiological parameters and neuropsychological performance, except for an overall relation between the P300 latencies and the total number of deviant test scores. CONCLUSION: Although the neurophysiological differences are subtle and the relation with the cognitive functioning in individual patients as measured by the neuropsychological examination is equivocal, the results suggest that there is neurophysiological support for cognitive dysfunction as a late complication of high-dose systemic chemotherapy in breast cancer.

bulletDepartment of Psychosocial research and Epidemiology, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam.