Increased fatigue and cognitive dysfunction in patients with colorectal cancer

This study examined whether patients with colorectal cancer have cognitive dysfunction or increased fatigue (tiredness). 

Cognitive function refers to a person’s ability to think or process information. Cognitive dysfunction can include problems with memory, learning new information, reading or understanding speech. Previous studies have reported that some women with breast cancer suffer from cognitive dysfunction. The reason for cognitive dysfunction is unclear but may be due to increased cytokines (proteins involved in controlling inflammation), hormone changes, or side-effects of drug treatment.

It had also been reported that patients with breast cancer suffer from fatigue. Again the cause of this is unclear but may be due to increased cytokines. No large studies have examined whether patients with colorectal cancer also suffer from cognitive dysfunction and fatigue.

This study examined cognitive function, psychological function and fatigue in 3 groups of patients. Group 1 included 281 patients with localized colorectal cancer (cancer that is confined to the intestine). Group 2 included 66 patients with locally recurrent (previously treated cancer that has returned to the intestine) or metastatic cancer (the cancer has spread beyond the intestines). Group 3 included 72 healthy individuals for comparison.

Cognitive dysfunction was more common in patients with localized cancer (45%) and metastatic cancer (47%) than in healthy individuals (15%). The most severely affected cognitive processes included attention, working memory and verbal learning. Female patients with localized colorectal cancer were more likely to experience cognitive impairment than male patients: 52% compared to 40%.

A higher rate of patients with localized colorectal cancer (52%) and metastatic cancer (68%) suffered from fatigue than healthy individuals (26%). Patients with cancer were also more likely to suffer from depression and anxiety than healthy individuals. There was no link between laboratory measures of cytokines and cognitive dysfunction.

The authors concluded that almost half of colorectal cancer patients have cognitive impairment and/or fatigue. The reason for cognitive dysfunction in patients remains unknown.