CRC Diagnosis Linked To Cognitive Deficits

Localised colorectal cancer is associated with cognitive impairment at diagnosis and after treatment

medwireNews: Patients with localised colorectal cancer (CRC) are at risk of cognitive deficits independent of the treatment they receive, suggests research published in the Journal of Clinical Oncology.

Cognitive impairment was significantly more common in 289 localised CRC patients than 72 healthy controls at both baseline (43 vs 15%) and at follow-up 12 months later (46 vs 13%). Cognitive deficit was as defined as a Global Deficit Score above 0.5, determined from a battery of clinical neuropsychological tests, or a prespecified standard deviation difference compared with healthy controls on one or more of the tests.

In particular, CRC patients were shown to have deficits in their processing speed, verbal learning and memory, and attention and working memory, report Janette Vardy, from Concord Repatriation General Hospital in New South Wales, Australia, and co-authors.

And decline in cognitive function between baseline and 12 months was detected in 20% of localised CRC patients compared with 4% of healthy controls.

However, the team did not find a significant difference in any neuropsychological test performance between the 173 localised CRC patients with stage II or III disease who were given adjuvant chemotherapy and the 116 patients with stage I or II disease who were not.

The neuropsychological test results were also comparable between the localised CRC patients and a group of 73 patients with limited metastatic or recurrent CRC.

The researchers emphasize that objectively defined cognitive function was independent of fatigue, quality of life and the presence of anxiety or depression. Nor was cognitive function significantly associated with cytokine levels, clotting factors, sex hormones or apolipoprotein E genotype.

Nevertheless, they note that self-reported cognitive impairment was more common in chemotherapy recipients at the 6-month check-up than in those not given adjuvant chemotherapy, and that there were moderate associations between self-reported cognitive symptoms and both fatigue, and anxiety and depression.

“This highlights the importance of assessing fatigue and anxiety/depression, and treating them if present, in patients who self-report cognitive impairment”, Janette Vardy et al write.

They conclude: “Our data show that the diagnosis of even localized cancer is associated with substantial rates of sustained cognitive impairment. Patients with a new diagnosis of cancer should be advised about possible cognitive effects of their disease.”


Vardy JL, Dhillon HM, Pond GR, et al. Cognitive function in patients with colorectal cancer who do and do not receive chemotherapy: A prospective, longitudinal, controlled study. J Clin Oncol 2015; Advance online publication 2 November. doi: 10.1200/JCO.2015.63.0905

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