Effects of high-dose and conventional-dose adjuvant chemotherapy on long-term cognitive sequelae in patients with breast cancer: an electrophysiologic study.
BACKGROUND
The mechanisms underlying cognitive deficits found in a number of patients with breast cancer treated with adjuvant chemotherapy are still unclear. In the current study, we used a combination of measures of brain electric activity and cognitive performance during information processing to elucidate the origin of these cognitive deficits.


METHODS
Twenty-nine patients at high risk with breast cancer treated with adjuvant conventional-dose cyclophosphamide/epirubicin/5-fluorouracil or adjuvant high-dose cyclophosphamide/thiotepa/carboplatin were compared with 23 patients with stage I breast cancer not treated with chemotherapy approximately 4 years after completion of treatment. We studied reaction times and the amplitudes and latencies of the P3, an electrophysiologic index of information processing, in a task with different conditions related to input, central, and output processing of information.


RESULTS
The amplitude of the P3 component was significantly reduced in patients with breast cancer treated with high-dose cyclophosphamide/thiotepa/carboplatin compared with patients with breast cancer not treated with chemotherapy. We observed no significant differences in reaction times and P3 latency between the treatment groups.


CONCLUSIONS
Our data show electrophysiologic alterations in patients with breast cancer treated with high-dose chemotherapy 4 years after completion of treatment. The observed P3 reduction might be a result of suboptimal phasic cortical arousal and problems with the allocation of processing resources in these patients.
Kreukels
Baudewijntje P C
BP
Department of Psycho-Social Research and Epidemiology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam.
Schagen
Sanne B
SB
Ridderinkhof
K Richard
KR
Boogerd
Willem
W
Hamburger
Hans L
HL
Muller
Martin J
MJ
van Dam
Frits S A M
FS
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D002490:Central Nervous System / Q000187:drug effects; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D003072:Cognition Disorders / Q000139:chemically induced* / Q000175:diagnosis; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods; D008875:Middle Aged; D009367:Neoplasm Staging; D011336:Probability; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate