Physiologic vasomotor symptoms are associated with verbal memory dysfunction in breast cancer survivors

Objective: Vasomotor symptoms (VMS), sleep disturbance, and cognitive complaints are common among women with a history of breast cancer and contribute to decreased quality of life. Studies in healthy women showed an association between verbal memory performance and physiologic VMS measured with ambulatory skin conductance monitors but not with VMS by self-report. We hypothesized that we would find a similar association in women with breast cancer. Methods: Participants included 30 female breast cancer survivors (mean age 52.7 y; 26.7% African-American) with moderate-to-severe VMS enrolled in a larger clinical trial of a nonhormonal intervention for VMS. At baseline, participants completed assessments of physiologic VMS, actigraphy-based assessments of sleep, questionnaires about mood, and two tests of verbal memory - Logical Memory (LM) and the California Verbal Learning Test (CVLT). Using baseline data, we conducted multivariate regression analyses to examine the association between VMS and memory, controlling for sleep and other factors. Results: On average, women reported 46% of total physiologic VMS. A higher frequency of physiologic VMS - but not reported VMS - was significantly associated with lower scores on the California Verbal Learning Test short-delay free recall (r[28] = -0.41, P = 0.03), long-delay free recall (r[28] = -0.42, P = 0.03), and total clustering, (r[28] = -0.39, P = 0.04). These associations were independent of sleep, mood, and other factors. Conclusions: Independent of their effect on sleep, VMS may be a modifiable contributor to memory difficulties in women with breast cancer. These findings underscore the importance of objective measurement of VMS in cognitive studies.