Abstract
OBJECTIVE: This study aimed to examine the characteristics of research conducted on nonpharmacological interventions for cognitive impairment in patients with breast cancer and identify the primary effects of nonpharmacological interventions through a systematic review and meta-analysis. METHODS: Five electronic databases were searched to identify all randomized controlled trial studies until September 30, 2022, using the key terms "breast cancer," "cognitive disorders," and their possible variations. The Cochrane Risk of Bias tool was used to assess risk of bias. The effect sizes were calculated in Hedges' g. Potential moderators influencing the intervention effects were explored. RESULTS: Twenty-three studies were included in the systematic review, and 17 studies were included in the meta-analysis. Among the nonpharmacological interventions for patients with breast cancer, cognitive rehabilitation and physical activity were the most common, followed by cognitive behavioral therapy. The meta-analysis indicated that nonpharmacological interventions had a significant effect on attention (g = 0.83; 95% CI: 0.14 to 1.52; I (2) = 76%), immediate recall (g = 0.33; 95% CI: 0.18 to 0.49; I (2) = 0%), executive function (g = 0.25; 95% CI: 0.13 to 0.37; I (2) = 0%), and processing speed (g = 0.44; 95% CI: 0.14 to 0.73; I (2) = 51%) among objective cognitive functions, as well as subjective cognitive function (g = 0.68; 95% CI: 0.40 to 0.96; I (2) = 78%). Intervention type and mode of delivery were potential moderators for the effects of nonpharmacological interventions on cognitive functions. CONCLUSIONS: Nonpharmacological interventions can improve subjective and objective cognitive functioning among patients with breast cancer undergoing cancer treatment. Therefore, it is necessary to provide nonpharmacological interventions by screening patients at high risk of cancer-related cognitive impairment. SYSTEMATIC REVIEW REGISTRATION: CRD42021251709.