Association of Circulating Levels of Inflammatory Cytokines and Chemotherapy-Associated Subjective Cognitive Impairment in a South African Cohort of Breast Cancer Patients

Background: The evidence links chemotherapy to cognitive impairment in breast cancer patients. This study assessed the link between subjective chemotherapy-related cognitive impairment and neuroinflammation in breast cancer patients. Methods: In a correlational study, 113 patients aged 21 to 60 years on chemotherapy regimens completed the Functional Assessment of Cancer Therapy-Cognition Test (FACT-Cog) as a measure of subjective cognitive functioning at three time points (baseline- T0, third cycle- T1, and sixth cycle- T2). The levels of inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-alpha (TNF-α)) were measured using an assay method and compared with the subjective cognitive impairment. Results: Midway through chemotherapy, higher levels of TNF-α were inversely linked with self-perceived cognitive performance, while higher levels of IL-1β were positively associated (p = 0.030). However, at the end of chemotherapy, only IL-8 (p = 0.50) was associated with higher self-perceived cognitive problems. Conclusions: The specific roles that various cytokines and their interactions may play in neuroinflammation or neuroprotection require further investigation.