Cognitive Function in Post-Menopausal Women with Breast Cancer Treated with Aromatase Inhibitors.

Abstract

Introduction: Cognitive function changes reported as distressing by women diagnosed with breast cancer have been of interest to clinicians and researchers. The majority of post-menopausal women diagnosed with early stage breast cancer are treated with anti-estrogen therapies, usually aromatase inhibitors (AI). Estrogen is essential for brain function that supports everyday activities requiring cognitive functions of controlled attention and working and verbal memory. Post-menopausal breast cancer survivors are vulnerable to age-related cognitive decline which may be compounded by treatment-associated estrogen deprivation adversely affecting their roles at home, work, school, and society. This study explored effects of AI therapy on cognitive function in post-menopausal women treated for early stage breast cancer. The biological theory of treatment-associated estrogen deprivation was linked to neurobehavioral theory underlying basic cognitive processes of controlled attention and working and verbal memory. Methods: Fifty post-menopausal women, 21 with breast cancer treated with AI, 10 with breast cancer receiving no AI, and 19 healthy controls were enrolled in this longitudinal, non-randomized, comparative study. Established neuropsychological measures (Digit Span, Controlled Oral Word Association Test, Attention Network Test) and self-report of cognitive function (Attentional Function Index) were administered at two time points coincident with pre-AI and 3 months of AI therapy. Comparative and repeated measures statistics were used to examine between and within group changes over time. Results: The AI group perceived worsening of cognitive function with more attentional lapses after three months of AI therapy in contrast to improvement in objective cognitive measures. There were no significant differences between AI and non-AI groups in objective or subjective measures of cognitive function. In comparison to healthy controls, the AI group demonstrated greater difficulty in high demand attention and working memory tasks. Similar group differences were noted in perceived cognitive function with greatest differences between the AI and healthy groups. The AI group perceived more attentional lapse over time than healthy controls. Conclusion: Post-menopausal breast cancer survivors treated with AI perceive cognitive decline despite objective improvement in attention and working memory. Nurses are instrumental in supporting these women and helping them to recognize and manage effects of cognitive decline in everyday life.