Cognitive impairment in breast cancer patients before surgery: results from a CANTO cohort subgroup.

Background: Twenty to 30% of patients with breast cancer have cognitive impairment after surgery and before adjuvant treatment, but very few studies have focused on cognition before any treatment. This study used a subgroup of women with newly diagnosed breast cancer from the French cancer and toxicities (CANTO) cohort to describe cognition before any treatment in comparison with a group of healthy controls (HC). Methods: Cognitive assessment was performed before any breast cancer treatment (surgery or neoadjuvant treatment) on women with newly diagnosed invasive stage I-III breast cancer and HCs. Objective cognitive performance, cognitive complaints, anxiety, depression, and fatigue were assessed. Objective cognitive impairment was defined according to International Cognition and Cancer Task Force recommendations. Results: Of the 264 included patients with breast cancer (54 +/- 11 years) and 132 age-matched HCs (53 +/- 9 years), overall objective cognitive impairment was observed in 28% of patients with breast cancer and 8% of HCs (P < 0.001). Cognitive complaints were reported by 24% of patients versus 12% of HCs (P < 0.01). Patients reported significantly more anxiety and emotional and cognitive fatigue than HCs (P < 0.01). After adjustment, significantly more patients with breast cancer had overall objective cognitive impairment than HCs [OR = 3.01; 95% confidence interval (CI): 1.31-6.88] without significant difference between groups for cognitive complaints (OR = 1.38; 95% CI: 0.65-2.92). Cognitive complaints were positively associated with fatigue (OR = 1.03; 95% CI: 1.02-1.05). Conclusions: In this prospective study, compared with HCs, patients with localized breast cancer had more objective cognitive impairment before any treatment. Cognitive complaints were mostly related to fatigue. Impact: Baseline assessment before treatment is important to assess the impact of each cancer treatment on cognition.