A Systematic Review Focused On Understanding the Effects of Modifiable Factors in Patients who Suffer from Chemotherapy Induced Cognitive Impairments or “Chemobrain”

Abstract

Background As the prevalence of cancer survivors increases, there have been increased reports of chemotherapy-induced cognitive impairment (CICI). Around 75% of cancer patients experience CICI during or after treatment. From the reported group, up to 35% will have persistent CICI for months to years following their treatments. In this review, the authors focused on modifiable factors (MFs) as variables that can be manipulated to change the impact of CICI on the patient's life. The MFs focused upon psychological factors, sleep, physical activity, and intervention programs. The authors aimed to establish that when certain interventions that address these MFs are added to treatment plans, it may help to decrease the impact of CICI. Search Methods: The authors used the PubMed database to identify articles to be potentially included in the review. A scoping review was conducted to narrow down the topics in relation to CICI. From here, the authors identified a set of factors deemed MFs. Using the inclusion and exclusion criteria, the authors started with 17,242 papers and narrowed down the review to 46 papers. The RoB2 tool from Cochrane Methods Bias was used to conduct risk basis assessment. Results The systematic review established that psychological factors, physical activity, and sleep quality/quantity affect the presence and severity of CICI. Furthermore, interventional programs and exercise can help decrease the effects of CICI. Meta-analysis was not conducted due to varying factors (cancer type, treatment type, and assessments conducted) across included studies. Discussion Cancer patients and survivors reported more severe CICI when depression, anxiety, fatigue, PTSD, decreased sleep quality and quantity were present. The severity of CICI significantly diminished with the use of physical activity programs, psychological programs, and cognitive training programs; however, the use of herbs, supplements, prescribed medication, Tibetan sound meditation, and EGG feedback showed little to no improvement in CICI. The findings suggest that when CICI is diagnosed at earlier stages, and supplementary interventions (medications, exercise programs cognitive behavioral therapy) are incorporated into treatment plans, the impact and severity of CICI can be decreased. This study urges more focus be placed on this aspect of chemotherapy treatment due to the increased prevalence of cancer survivors in the population. Funding: There was no funding provided for this systematic review. Registration: The study protocol was registered on PROSPERO on Aug 18,2022 (CRD42022349831).