Reduced prefrontal activation during working and long-term memory tasks and impaired patient-reported cognition among cancer survivors postchemotherapy compared with healthy controls.
BACKGROUND
Patients who receive adjuvant chemotherapy have reported cognitive impairments that may last for years after the completion of treatment. Working memory-related and long-term memory-related changes in this population are not well understood. The objective of this study was to demonstrate that cancer-related cognitive impairments are associated with the under recruitment of brain regions involved in working and recognition memory compared with controls.


METHODS
Oncology patients (n = 15) who were receiving adjuvant chemotherapy and had evidence of cognitive impairment according to neuropsychological testing and self-report and a group of age-matched, education group-matched, cognitively normal control participants (n = 14) underwent functional magnetic resonance imaging. During functional magnetic resonance imaging, participants performed a nonverbal n-back working memory task and a visual recognition task.


RESULTS
On the working memory task, when 1-back and 2-back data were averaged and contrasted with 0-back data, significantly reduced activation was observed in the right dorsolateral prefrontal cortex for oncology patients versus controls. On the recognition task, oncology patients displayed decreased activity of the left-middle hippocampus compared with controls. Neuroimaging results were not associated with patient-reported cognition.


CONCLUSIONS
Decreased recruitment of brain regions associated with the encoding of working memory and recognition memory was observed in the oncology patients compared with the control group. These results suggest that there is a reduction in neural functioning postchemotherapy and corroborate patient-reported cognitive difficulties after cancer treatment, although a direct association was not observed. Cancer 2016;122:258-268. © 2015 American Cancer Society.
Division of Clinical Psychology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Lei
L
Wang
Division of Clinical Psychology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Alexandra C
AC
Apple
Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Matthew P
MP
Schroeder
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Anthony J
AJ
Ryals
Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Joel L
JL
Voss
Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.|Advocate Memory Center, Advocate Lutheran General Hospital, Park Ridge, Illinois.|Department of Neurology, Chicago Medical School at Rosalind Franklin University, North Chicago, Illinois.
Darren
D
Gitelman
Department of Psychiatry and Behavioral Sciences, NorthShore University, Evanston, Illinois.
Jerry J
JJ
Sweet
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Zeeshan A
ZA
Butt
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
David
D
Cella
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Lynne I
LI
Wagner
D000328:Adult; D000367:Age Factors; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000139:chemically induced* / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D057567:Memory, Long-Term / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects*; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000473:pathology*; D012016:Reference Values; D018570:Risk Assessment; D012737:Sex Factors; D017741:Survivors; D013647:Task Performance and Analysis
D000970:Antineoplastic Agents
cancer-related cognitive impairment (CRCI); functional magnetic resonance imaging (fMRI); patient-reported outcomes (PRO); recognition memory; working memory