Predictors of trajectories of cognitive change in women with breast cancer.

Abstract

149 Background: Subgroups of women with breast cancer may be vulnerable to cognitive changes with systemic therapy. Given our previous findings of changes in concentration and working memory (WM), we sought to identify subgroups of women with distinct trajectories of concentration and WM and determine predictors of subgroup membership. Methods: Cognitive function was assessed before systemic therapy and semi-annually to 18 months post-therapy initiation in 181 postmenopausal women with breast cancer who received the AI, anastrozole, or chemotherapy+anastrozole and at matched time points for 110 healthy controls. Group-based trajectory modeling identified subgroups of women with distinct trajectories of concentration and WM (as measured by composites of mean z-scores for neuropsychological tests). Multinomial logistic regression identified predictors of subgroup membership. Results: A 3-group model was found for concentration: low and constant (25%; b0 = -0.84), normal but declining (65%; b0 = 0.05, b1 = -0.04), and high and constant (10%; b0 = 1.29). At baseline, the low subgroup was older (p = .009) and had lower psychomotor speed (p = .035) than the normal subgroup. Controlling for baseline concentration z-scores, membership in the low concentration subgroup was associated with greater age (p < .001), more fatigue (p < .001), and poorer self-reported cognitive function (p = .001). For WM, a 2-group model was identified: low and increasing (35%; b0 = -0.67, b1 = 0.11) and high and increasing (65%; b0 = 0.32, b1 = 0.07). At baseline, the low WM subgroup was older (p = .008), had less education (p < .001), and scored lower on the NART verbal IQ test (p < .001). Controlling for baseline WM z-scores, membership in the low WM subgroup was associated with poorer executive function (p < .001), receipt of anastrozole alone (p = .011), and worse pain (p = .002) and anxiety (p = .008). Conclusions: Subgroups of women are more vulnerable to poorer concentration and WM during adjuvant therapy for breast cancer. Advancing age, less education, and co-occurring symptoms are associated with membership in these vulnerable subgroups.