Neuropsychological function in high-risk breast cancer survivors after stem-cell supported high-dose therapy versus standard-dose chemotherapy: evaluation of long-term treatment effects

Background: Studies on cognitive functioning in breast cancer patients point out that a subset of women exhibit chemotherapy-related neuropsychological impairment. Thereby, high-dose therapy may elevate the risk of cognitive dysfunctions. The primary purpose of the study was to evaluate the impact of high-dose versus standard-dose chemotherapy on the late neuropsychological outcome in randomized assigned high-risk breast cancer survivors. Next to focusing prevalence, function specificity and extent of cognitive impairment, the question as to whether doses-dependant group differences occur was investigated. Patients and methods: Twenty-four high-dose and 23 standard-dose patients 5 years, on average, after treatment underwent a comprehensive neuropsychological assessment. In addition, 29 early-stage breast cancer patients matched for age, education and time since treatment were recruited as a comparison group. Results: Global cognitive impairment was observed in 8% of high-dose versus 13% of standard-dose compared with 3% of early-stage breast cancer patients. Compared with normative data, all patient groups performed worse on one attention subtest measuring the simple reaction time (P < 0.001 in each case). By contrast, no significant between-group differences on the late neuropsychological outcome were found. Conclusions: Five years after treatment, standard-dose patients were slightly, but not significantly, more impaired in cognitive performance than high-dose patients.