Change in cognitive function after chemotherapy: a prospective longitudinal study in breast cancer patients.

Some breast cancer survivors experience cognitive decline following chemotherapy. We prospectively examined changes in cognitive performance among high-risk breast cancer patients who had received high-dose chemotherapy with cyclophosphamide, thiotepa, and carboplatin (CTC group; n = 28) or standard-dose chemotherapy with 5-fluorouracil, epirubicin, and cyclophosphamide (FEC group; n = 39); stage-I breast cancer patients who had received no systemic chemotherapy (no-CT group; n = 57); and healthy control subjects (n = 60). All patients underwent neuropsychologic testing before and 6 months after treatment (12-month interval); control subjects underwent repeated testing over a 6-month interval. No differences in cognitive functioning between the four groups were observed at the first assessment. More of the CTC group than the control subjects experienced a deterioration in cognitive performance over time (25% versus 6.7%; odds ratio [OR] = 5.3, 95% confidence interval [CI] = 1.3 to 21.2, P = .02). No such difference was observed for the FEC or the no-CT groups (FEC versus control: OR = 2.2, 95% CI = 0.5 to 9.1, P = .27; no-CT versus Control: OR = 2.2, 95% CI = 0.6 to 8.0; P = .21). Some cytotoxic treatment for breast cancer affects cognition in a subset of women.