Chemotherapy-induced cognitive impairments: A systematic review of the animal literature

Whilst chemotherapy is a widely used anti-cancer treatment, a subset of patients experience cognitive decline. However, cancer type, treatment regimen, fatigue and anxiety can influence cognitive status. Rodent research has overcome these confounds to systematically evaluate cognitive domains and underlying neural mechanisms disrupted by chemotherapy treatment. Therefore, a systematic review was conducted in June 2017 to examine the relationship between chemotherapy and cognitive decline in animal models. A comprehensive literature search was performed in PubMed, PsycInfo, Web of Science, Scopus and Medline databases. A quality assessment yielded a total of 83 papers to be considered for the review. A critical assessment of research papers indicated that cisplatin, CMF and MIX + 5-FU chemotherapy regimens produced strong deficits in short term memory, long term memory and executive control. An assessment of specific cognitive domains illustrated that short term memory was strongly impaired by chemotherapy treatment, often associated with impaired neurogenesis, inflammation and mitochondrial dysfunction in the hippocampus. Pharmacological treatments were the most common intervention to reduce the prevalence of chemobrain.