title: Endocrine treatment-associated cognitive impairment in breast cancer survivors: evidence from published studies.
abstract: Endocrine-based treatments are the mainstay of therapy for postmenopausal women with breast cancer; yet concern has been raised about potential adverse cognitive effects. We performed a systematic review of the published literature to evaluate whether endocrine-based treatments for breast cancer are associated with changes in cognitive domains and whether these effects are more pronounced with advanced age. An electronic database search was performed. Original investigations that examined the effects of endocrine treatment on cognitive function were identified. Data were abstracted and studies were assessed for risk of bias. A total of 21 unique studies (n = 2398) were identified. Ten were short-term (duration ≤ 2 years) and 11 were long-term (duration > 2 years). Nine (43 %) studies had a sample size ≤100 subjects; 9 (43 %) were longitudinal, with baseline measurement before treatment initiation. No studies were primary randomized clinical trials. While there was heterogeneity in the neuropsychological measures used, tests could be grouped into the cognitive domains that they assessed. Compared to breast cancer or healthy controls, endocrine therapy was associated with impaired performance on neuropsychological testing. No study explored the association between age and changes in cognitive performance. Overall, endocrine therapies were associated with greater cognitive deficits compared to surgical and healthy controls; yet, lack of randomized trial data and heterogeneity in design of many studies limited any definitive conclusions. Despite older women being at highest risk for the development of cognitive impairment, advanced age has not been adequately explored.
authors.affiliation: Division of Geriatric Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. pelee@providencehealth.bc.ca.|AD Clinic, Centre for Brain Health, 2nd Floor 2215, Wesbrook Mall, Vancouver, V6T 1Z3, BC, Canada. pelee@providencehealth.bc.ca.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Lee
authors.affiliation: Department of Family & Community Medicine Faculty of Medicine, Sunnybrook Health Sciences Centre and University of Toronto, Toronto, Canada.|Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada.
authors.forename: Mary C
authors.initials: MC
authors.lastname: Tierney
authors.affiliation: Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada.|Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Kathleen I
authors.initials: KI
authors.lastname: Pritchard
authors.affiliation: Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada.|Department of Medicine, University of Toronto, Toronto, ON, Canada.|Institute for Clinical Evaluative Sciences, Toronto, ON, Canada.|Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, ON, Canada.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Rochon
mesh_terms: D000367:Age Factors; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000523:psychology; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects*; D002986:Clinical Trials as Topic; D060825:Cognitive Dysfunction / Q000139:chemically induced*; D005260:Female; D006801:Humans; D009483:Neuropsychological Tests; D017698:Postmenopause; D017741:Survivors
chemical_list: D018931:Antineoplastic Agents, Hormonal
keywords: Aged; Antineoplastic agents, hormonal; Breast neoplasm; Cognition disorders