Neurophysiological evaluation of late effects of adjuvant high-dose chemotherapy on cognitive function.
OBJECTIVE
To evaluate late neurotoxicity of adjuvant high-dose (HD) chemotherapy versus standard-dose (SD) chemotherapy by event-related potentials (ERP) and quantitative electroencephalography (qEEG).


METHODS
From a randomized study in high-risk breast cancer patients on the efficacy of high-dose versus standard-dose adjuvant chemotherapy, late effects on cognitive functioning were analyzed by neuropsychological tests. Cognitive impairment was found in 32% of the HD group, 17% of the SD group and in 9% of a control group of stage I breast cancer patients not treated with chemotherapy. In 17 consecutive patients in the HD group and 16 consecutive patients in the SD group neurophysiological tests were performed, consisting of P300 and qEEG. Results of patients treated with chemotherapy were compared with results of 14 control patients not treated with chemotherapy. All patients were tested two years after treatment.


RESULTS
Asymmetry of the alpha rhythm of > or =0.5 Hz was found in 7 HD patients, 2 SD patients and in none of the control patients (p = 0.01). No differences were found between the groups with regard to frequency of alpha rhythm, alpha blocking and latency of P300. No correlation was found between neurophysiological parameters and neuropsychological performance, except for an overall relation between the P300 latencies and the total number of deviant test scores.


CONCLUSIONS
Although the neurophysiological differences are subtle and the relation with the cognitive functioning in individual patients as measured by the neuropsychological examination is equivocal, the results suggest that there is neurophysiological support for cognitive dysfunction as a late complication of high-dose systemic chemotherapy in breast cancer.
Schagen
S B
SB
Department of Psychosocial research and Epidemiology, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam.
Hamburger
H L
HL
Muller
M J
MJ
Boogerd
W
W
van Dam
F S
FS
D000513:Alpha Rhythm / Q000187:drug effects; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001007:Anxiety; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000523:psychology*; D016190:Carboplatin / Q000008:administration & dosage; D017024:Chemotherapy, Adjuvant; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000139:chemically induced; D003520:Cyclophosphamide / Q000008:administration & dosage; D003863:Depression; D004569:Electroencephalography / Q000187:drug effects; D015251:Epirubicin / Q000008:administration & dosage; D018913:Event-Related Potentials, P300 / Q000187:drug effects; D005071:Evoked Potentials / Q000187:drug effects; D005221:Fatigue; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D007360:Intelligence; D016018:Least-Squares Analysis; D008875:Middle Aged; D009483:Neuropsychological Tests; D013852:Thiotepa / Q000008:administration & dosage
D015251:Epirubicin; D003520:Cyclophosphamide; D013852:Thiotepa; D016190:Carboplatin; D005472:Fluorouracil