From the Sydney Cancer Centre, University of Sydney, New South Wales Cancer Institute, Concord, New South Wales, Australia
Authors’ disclosures of potential conflicts of interest are found at the end of this article.
Address reprint requests to Janette Vardy, MD, PhD, FRACP, Sydney Cancer Centre, Concord Repatriation General Hospital, Hospital Road, Concord, New South Wales 2139, Australia; e-mail: jvardy{at}med.usyd.edu.au
Overview: A large percentage of survivors of cancer report that their memory and concentration are impaired after cancer treatment. For most patients, any cognitive impairment is subtle and improves after ceasing chemotherapy, but for a subset of patients, the symptoms are sustained and can affect their quality of life and ability to function. Earlier studies, mainly cross-sectional in design, reported that 15% to 50% of adults with solid tumors not involving the central nervous system have cognitive impairment after chemotherapy, but recent studies suggest that approximately 20% to 30% have cognitive problems. Prospective studies also report that up to 30% of patients with breast and colorectal cancer have cognitive impairment before receiving chemotherapy. Most studies report a decline in cognition in a subset of patients after chemotherapy, although some studies have reported no significant change. There is only a weak association between self-reported cognitive function and neuropsychological performance on formal cognitive testing. Self-reported cognitive impairment is strongly associated with fatigue, symptoms of anxiety and depression, and impaired quality of life; however, none of these symptoms is correlated with neuropsychological impairment on cognitive testing. The underlying mechanisms of cognitive impairment in survivors of cancer are unknown, and there is no proven intervention to prevent such impairment from occurring or to treat it once it has occurred.
