Does lifetime exposure to hormones predict pretreatment cognitive function in women before adjuvant therapy for breast cancer?

OBJECTIVE: Women with breast cancer have been found to have poorer cognitive function before the initiation of systemic adjuvant therapy than their age- and education-matched counterparts. The basis for this may partly include hormone exposure during the course of a woman's life.
METHODS: We compared cognitive function between postmenopausal women with breast cancer before the initiation of systemic adjuvant therapy and healthy age- and education-matched postmenopausal women and examined whether factors related to lifetime exposure to hormones predicted cognitive function before therapy.
RESULTS: We found that, compared with healthy women, women with breast cancer had poorer memory (P = 0.05) and attention (P = 0.006). Controlling for the covariates age and estimated verbal intelligence, we found that factors related to greater lifetime hormone exposure (oral contraceptive use, greater years since menopause, and longer duration of hormone therapy) predicted cognitive function (executive function, verbal learning and memory, attention, psychomotor efficiency, and visual sustained attention) in women with and without breast cancer but did not explain the differences in cognitive function observed at pretreatment in women with breast cancer.
CONCLUSIONS: Other factors may explain the poorer pretreatment cognitive function in women with breast cancer, including persistent effects of surgical operation and anesthesia, sleep problems, and tumor-related factors. Additional studies are needed to explicate the basis of poorer pretherapy cognitive function in this population.