Factors associated with cancer-related cognitive impairment in patients with lung cancer: A systematic review

Purpose: Cognitive impairment is common in lung cancer patients and impacts their quality of life. Little is known about the etiology of cognitive impairment in lung cancer patients. However, the associated factors of cognitive impairment among lung cancer patients have not been systematically reviewed. This review aimed to summarize the factors related to cognitive impairment among lung cancer patients. Methods: PubMed, EMBASE, PsycINFO, CINAHL Plus, and Web of Science were searched to retrieve articles published from data inception until January 21, 2024, focusing on factors associated with cognitive impairment among lung cancer patients. Critical appraisal was undertaken by two reviewers independently using the Newcastle–Ottawa Scale. Results: A total of 17 observational studies were included. The results showed that 20 factors are associated with cognitive impairment, including psychological factors (loneliness, fatigue, anxiety, depression, high symptom burden, and baseline cognitive impairment), lifestyle and functional factors (daily step counts, smoking, and activities of daily living or instrumental activities of daily living impairments), medical treatment factors (cranial irradiation, chemotherapy, lobar resection, postoperative delirium, and on medication), and neuroimmunological factors (have neuronal autoantibodies, altered Default Mode Network connectivity, dysregulation in glutamate and glutamate metabolism, mitochondrial dysfunction, blood-brain barrier leakage, and reduced T-lymphocytes). Conclusion: This is the first study to systematically review 20 factors associated with cognitive impairment among lung cancer patients, encompassing psychology, lifestyle and functional, medical treatment, and neuroimmunological factors. These findings can help clinicians identify at-risk patients and develop evidence-based interventions to prevent cognitive impairment among lung cancer patients.