Pretreatment cancer related cognitive impairment and associated psychological factors: a systematic review

Introduction: Cancer related cognitive impairment (CRCI) describes issues patients can experience with attention, memory and focus. Understanding the causes of CRCI and the experience of CRCI prior to surgery or treatment is important. Exploring the role of anxiety and depression can aid in understanding how psychological variables may interact with CRCI. Inclusion of both objective CRCI and subjective measures also helps to further understand the relationship between neuropsychological test scores, and self-reported experience. This systematic review was conducted to explore levels of objectively measured and subjectively reported pretreatment CRCI, their inter-relationship, their association with anxiety and depression across cancer types, and changes in CRCI trajectory. Methods: The review was conducted in line with PRISMA guidelines. Five databases were searched: PsycINFO, CINAHL, MEDLINE, PubMed and EMBASE. Extracted data was narratively synthesised. Results: Twenty-nine papers remained after full-text screening. Papers varied across cancer types, study design and measurement tools. Sixteen papers included a healthy control (HC) arm. Objective and Subjective CRCI levels were reported both relative to HCs and using scoring criteria or norms. Evidence supported both objective and subjective pretreatment CRCI, but variance increased complexity. Results support relationships between subjective CRCI and psychological variables. Little support was found for a relationship between objective and subjective CRCI. CRCI trajectory across time was explored, but heterogeneity limited further analysis. Conclusion: Support was found for pretreatment CRCI and relationships between anxiety, depression and subjective cognitive impairment. Variance across study measurement, design and cancer types limited future analysis of variables. Increases in subjective impairment were also observed over time. This review highlights the potential role of psychological factors in pretreatment CRCI, the need for standardization across CRCI research and the importance of control groups as well as norms for analysis to further our understanding of pretreatment CRCI. The findings of this review will help inform clinical care and the development of appropriate interventions for care. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023392837, CRD42023392837.