Cognitive function of older patients receiving adjuvant chemotherapy for breast cancer: a pilot prospective longitudinal study

OBJECTIVES: To report on the longitudinal cognitive functioning of older women receiving adjuvant chemotherapy for breast cancer. DESIGN: Neuropsychological and functional status testing were performed before chemotherapy and 6 months after chemotherapy. SETTING: Cancer center. PARTICIPANTS: Thirty-one patients aged 65 and older with Stage I to III breast cancer. Of the 31 patients enrolled, three refused post-testing, and 28 were evaluable. MEASUREMENTS: The following domains of cognitive function were examined: attention; verbal memory; visual memory; and verbal, spatial, psychomotor, and executive functions. RESULTS: Participants had a mean age of 71 (range 65-84): 39% Stage I, 50% Stage II, and 11% Stage III. The number of scores 2 standard deviations (SDs) below the norm were calculated for each patient before and 6 months after chemotherapy; 14 (50%) had no change, 11 (39%) worsened, and three (11%) improved (P=.05). Seven patients (25%) experienced a decline in cognitive function, defined as a 1-SD decline from pre- to post-testing in two or more neuropsychological domains. Exploratory analyses revealed no significant difference between functional status, comorbidity, and depression scale scores and change in overall quality-of-life scores before and after chemotherapy. CONCLUSION: In this cohort of older women receiving adjuvant chemotherapy, a subset experienced a decline in cognitive function from before chemotherapy to 6 months after chemotherapy. Further prospective study is needed to confirm these observations and to identify the subgroup at special risk.