Neurocognitive Effects of Chemotherapy for Colorectal Cancer: A Systematic Review and a Meta-Analysis of 11 Studies

Abstract

Chemotherapy-related cognitive impairment (CRCI) is a controversial concept not much explored on colorectal cancer patients. Materials and Methods We identified eleven prospective studies: eight studies on 696 colorectal cancer patients who received chemotherapy and three studies on 346 rectal cancer patients who received neoadjuvant chemoradiotherapy. Standardized mean differences (SMDs) of neuropsychological test results and the cognitive quality-of-life scale were calculated using random effect models. A meta-regression was conducted to investigate the association between mean study population age and effect sizes. Results The association between chemotherapy and cognitive impairment was not clear in colorectal cancer patients (SMD, 0.003; 95% confidence interval,-0.080 to 0.086). However, a metaregression showed that older patients are more vulnerable to CRCI than younger patients (β=-0.016, p < 0.001). Conclusion Chemotherapy has an overall positive negligible effect size on the cognitive function of colorectal patients. Age is a significant moderator of CRCI.

Effect of chemotherapy and radiotherapy on cognitive impairment in colorectal cancer: evidence from Korean National Health Insurance Database Cohort

“…a h e a d o f p r i n t regression from our previous systematic review and meta-analysis on cognitive decline after chemotherapy in colorectal cancer patients suggested that older colorectal cancer patients are more likely to suffer from cognitive impairment after receiving chemotherapy, [12] further supporting the hypothesis. However, the studies that we previously reviewed consisted of studies utilizing relatively small and selected populations (N<500).…”

“…It has been hypothesized that older patients with cancer are vulnerable to cognitive impairment after chemotherapy [ 9 ], as their cognitive reserve—the capacity of the brain to sustain external and internal neuropathological burdens [ 10 ]—is diminished [ 11 ]. A meta-regression from our previous systematic review and meta-analysis on cognitive decline after chemotherapy in colorectal cancer patients suggested that older colorectal cancer patients are more likely to suffer from cognitive impairment after receiving chemotherapy [ 12 ], further supporting this hypothesis. However, the studies that we previously reviewed utilized relatively small and selected populations (n<500).…”

Effect of Chemotherapy and Radiotherapy on Cognitive Function in Colorectal Cancer: Evidence from National Representative Longitudinal Database

“…It has been hypothesized that older patients with cancer are vulnerable to cognitive impairment after chemotherapy, [9] as their cognitive reserve, the capacity of the brain that helps it sustain the external and internal neuropathological burden, [10] are diminished. [11] A meta-regression from our previous systematic review and meta-analysis on cognitive decline after chemotherapy in colorectal cancer patients suggested that older colorectal cancer patients are more likely to suffer from cognitive impairments after receiving chemotherapy, [12] further supporting the hypothesis. However, previous studies that our group reviewed consisted of studies utilizing relatively small and selected population (N<500), so epidemiologic evidence from nationwide representative population with large sample is warranted.…”

“…Previous studies on "chemo-brain" in colorectal cancer patients did not suggest consistent direction of evidence4, 5. Our previous meta-analysis of previous studies showed that older patients are more likely to experience cognitive impairments after chemotherapy [12], but studies our groups reviewed had limited numbers of participants within each study, limiting the statistical power. Additionally, the effects of each chemotherapy agents were not described separately in previous studies.…”

Chemotherapy-induced functional brain abnormality in colorectal cancer patients: a resting‐state functional magnetic resonance imaging study

“…Moreover, the impaired cognition was related to anxiety, depression, fatigue and poorer QOL, which suggested that these negative concomitant symptoms might be associated with cancer-related distress or negative appraisal and decreased tolerance or resilience to manage cancer-related pain and chemotherapy-related side-effects ( 11 – 13 ). A meta-analysis study also found that older CRC patients were more vulnerable to cognitive impairment after chemotherapy, and preventive measures and rehabilitation programs could reduce the risk of developing chemotherapy-induced cognitive impairment ( 14 ). A prospective, longitudinal, controlled study showed that 36%-52% CRC patients had cognitive impairment including working memory, attention, verbal memory and processing speed ( 15 ).…”