A prospective longitudinal study of chemotherapy-induced cognitive changes in breast cancer patients.

Purpose: Evidence for chemotherapy-induced cognitive impairment remains inconclusive. This study was designed to determine the trajectory of cognitive function over time in women with breast cancer, who received doxorubicin and cyclophosphamide (AC) alone or followed by a taxane. Associations between changes in cognitive function and potential covariates including anxiety, depression, fatigue, hemoglobin level, menopausal status, and perception of cognitive function were evaluated.

Methods: The Repeatable Battery for the Assessment of Neuropsychological Status, Stroop Test, and Grooved Pegboard were used to assess cognitive function in a group of 71 women prior to chemotherapy, a week after completing the last cycle of AC, as well as 1 week and 6 months after the completion of all chemotherapy.

Results: Cognitive impairment was found in 23% of women prior to chemotherapy. Hierarchical linear modeling showed significant decreases after receiving chemotherapy followed by improvements 6 months after the completion of chemotherapy in the cognitive domains of visuospatial skill (p < 0.001), attention (p = 0.022), delayed memory (p = 0.006), and motor function (p = 0.043). In contrast, immediate memory, language, and executive function scores did not change over time.

Conclusion: These results suggest that having a breast cancer diagnosis may be associated with cognitive impairment. While chemotherapy may have a negative impact on cognitive function, chemotherapy-related impairments appear to be more acute than chronic side effects of therapy. Further studies are needed to provide insight into the clinical significance and potential mechanisms of cancer and treatment-related cognitive impairments.