Purpose: This study examined (a) whether cancer patients in two cohorts (patients awaiting for their first chemotherapy; patients undergoing chemotherapy) self-report greater cognitive impairment, both in prevalence and severity, compared to a cohort of actively-employed non-cancer controls; and (b) if any differences in self-reported cognitive impairment are associated with demographic and selected psycho-neurological factors (fatigue, stress, and sleep disturbance).
Methods: Data for two cancer patient cohorts (60 in the pre-chemotherapy cohort and 81 in the active-chemotherapy cohort) were collected from a conveniently selected University Hospital in South Korea, from July 2012 to January 2014. The data for non-cancer healthy controls (n=116) were collected in October 2016 from a conveniently selected community setting. Analysis of variance and chi-square tests were performed to examine the differences of three cohorts in cognitive impairment, demographic and psycho-neurological factors. Hierarchical regressions (both linear and logistic) were performed to predict the cognitive impairment measured in the Functional Assessment of Cancer Therapy–Cognitive Function (Wagner et al., 2009).
Results: Compared to the non-cancer control, both patient cohorts experienced cognitive impairment significantly more severely and more prevalently (18 % in healthy subject cohort vs. 40.7%, 55% in cancer patient cohorts, p < .001). After controlling for the effects of the selected psycho-neurological factors, however, cancer patient cohorts did not statistically differed in the prevalence or in the severity of cognitive impairment from the healthy non-cancer control (all ps >.05). Age, fatigue, and stress were the main factors that accounted for the prevalence as well as the severity of cognitive impairment.
Conclusion: The association with subjective cognitive impairments with psycho-neurological factors has been reported in many previous reports with cancer patients (Chen et al., 2012; Gehring et al., 2015; Myers et al., 2015). Further, the present study found that the psycho-neurological factors may play a pivotal role in experiencing subjective cognitive impairments in cancer patients as well as in general population. Unhealthy psycho-neurological status that is associated with cancer diagnosis and its treatment impairs cognitive function and managing such psycho-neurological status is the key to improve the cognitive function in cancer patients.