Is cognitive dysfunction a complication of adjuvant chemotherapy in the older patient with breast cancer?

For a number of years, patients have anecdotally reported changes in memory and concentration problems after receiving chemotherapy for breast cancer. Neuropsychological studies have been performed to seek objective evidence as to the existence and extent of this phenomenon; however, these studies were primarily performed in younger women and there is sparse data regarding the impact of adjuvant chemotherapy on an older woman's cognition. The objective of this paper was to evaluate the current literature in order to propose ways to overcome methodological limitations of studies to consider whether chemotherapy-associated cognitive dysfunction exists in older patients and if so, who is at risk. A systematic review of relevant literature was performed including study design, mean age of participants, treatment received, neuropsychological tests employed, timing of assessments, definition of cognitive impairment, and results. The literature primarily consists of small studies, which lack a prospective longitudinal design, vary in design measures, and exclude older patients who are at greatest risk for cognitive impairment. Since aging is the number one risk factor for breast cancer, future studies of the neuropsychological impact of chemotherapy should include older patients.