MedicalResearch.com Interview with:
Dr Janette Vardy BMed (Hons), PhD, FRACP
A.Prof of Cancer Medicine
University of Sydney
Medical Oncologist ,Concord Cancer Centre
Concord Repatriation & General Hospital
Medical Research: What is the background for this study?
Dr. Vardy: Many patients complain that their memory and concentration is not as good after chemotherapy. Most of the studies have been in younger women with breast cancer, and are often limited by small sample sizes and short term follow up. This is the largest longitudinal cohort study assessing impacts of cancer and its treatment on cognitive function.
We evaluated changes in cognitive function in 289 men and women with localized colorectal cancer (CRC), comparing those who received chemotherapy to those who did not require chemotherapy, 73 with metastatic disease, and a group of 72 healthy controls.?The localized CRC patients were assessed at baseline (soon after diagnosis and prior to any chemotherapy), 6, 12 and 24 months. The healthy controls and metastatic group were assessed at baseline, 6 and 12 months. We also examined underlying mechanisms.
Medical Research: What are the main findings?
Dr. Vardy: We found that people diagnosed with colorectal cancer are 3 times more likely to have cognitive impairment when tested soon after their cancer diagnosis (but prior to any chemotherapy) than healthy controls, and this effect was sustained at 12 months post-diagnosis. Interestingly there was no difference in rates of objective cognitive impairment at any timepoint in colorectal cancer patients who received chemotherapy and those who did not.
More participants who received chemotherapy had cognitive symptoms at 6 months (about the time chemotherapy ended) but by 12 months there was no difference in cognitive symptoms between the groups.
We did not find an association between global objective cognitive function and fatigue, quality of life or symptoms of anxiety/depression. There was only a weak association between objective cognitive function and cognitive symptoms. Cytokine levels were elevated in colorectal cancer subjects compared to healthy controls at all timepoints, but there was no consistent association between cytokine levels and cognitive impairment. Despite an extensive evaluation of underlying mechanisms we did not find the cause of the cognitive impairment.
Medical Research: What should clinicians and patients take away from your report?
Dr. Vardy: Approximately 45% of people with colorectal cancer experience changes in their memory and processing of information, compared to ~15% of people who had not had cancer. The mechanisms of cognitive impairment remain unknown.
It is important that cancer health professionals are aware that their patients with colorectal cancer may experience deficits in their memory and concentration due to the disease and that this may be exacerbated, at least in the short term, by chemotherapy.
Health professionals could help patients prepare for and cope with these changes by informing patients that it may happen. If the problems persist patients should be referred to a neuropsychologist for assessment.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Vardy: Future research needs to focus on the underlying mechanisms, and how to prevent and/or treat the cognitive impairment.
Dr Janette Vardy BMed (Hons), PhD, FRACP (2015). Patients with Colon Cancer May Have Memory and Cognitive Impairments