Trajectories of self‐reported cognitive function in postmenopausal women during adjuvant systemic therapy for breast cancer

Objective In a sample of 368 postmenopausal women, we (1) determined within-cohort and between-cohort relationships between adjuvant systemic therapy for breast cancer and self-reported cognitive function during the first 18 months of therapy and (2) evaluated the influence of co-occurring symptoms, neuropsychological function, and other covariates on relationships. Methods We evaluated self-reported cognitive function, using the Patient Assessment of Own Functioning Inventory (PAOFI), and potential covariates (e.g., co-occurring symptom scores and neuropsychological function z-scores) in 158 women receiving aromatase inhibitor (AI) therapy alone, 104 women receiving chemotherapy followed by AI therapy, and 106 non-cancer controls. Patients were assessed before systemic therapy and then every 6 months, for a total of four assessments over 18 months. Controls were assessed at matched time points. Mixed-effects modeling was used to determine longitudinal relationships. Results Controlling for covariates, patients enrolled before chemotherapy reported poorer global cognitive function (p < 0.001), memory (p < 0.001), language and communication (p < 0.001), and sensorimotor function (p = 0.002) after chemotherapy. These patients reported poorer higher-level cognitive and intellectual functions from before chemotherapy to 12 months after initiation of AI therapy (p < 0.001). Higher levels of depressive symptoms (p < 0.001), anxiety (p < 0.001), and fatigue (p = 0.040) at enrollment were predictors of poorer cognitive function over time. PAOFI total score was a predictor of executive function (p = 0.048) and visual working memory (p = 0.005) z-scores, controlling for covariates. Conclusions Findings provide further evidence of poorer self-reported cognitive function after chemotherapy and of relationships between co-occurring symptoms and cognitive changes. AI therapy alone does not have an impact on self-reported cognitive function. Copyright © 2015 John Wiley & Sons, Ltd.