Aberrant Within- and Between-Network Connectivity in Chemotherapy Treated Breast Cancer Patients: A Longitudinal Resting State Functional MRI Study
Abstract Background Previous studies have found abnormal structural and functional brain alterations in breast cancer survivors undergoing chemotherapy. However, the network-level brain changes following chemotherapy remains unknown. The purpose of this study was to investigate the dynamic changes of large-scale intra- and inter- network functional connectivity in chemotherapy-treated breast cancer patients. Methods Eighteen breast cancer patients were evaluated with resting state functional MRI (rs-fMRI), neuropsychological tests and blood examination before postoperative chemotherapy (t0), one week after completing chemotherapy (t1) and six months after completing chemotherapy (t2). Nineteen age- and education level-matched healthy controls (HC) were also recruited. Independent component analysis (ICA) was performed to assess network component using rs-fMRI data. The functional network changes were then correlated with cognitive assessment scores and blood biochemical indexes. Results One-way repeated measures ANOVA revealed significantly changed within-network functional connectivity, which mainly located in the default mode network (DMN), frontoparietal network, visual network and self-referential network. Post-hoc test showed that most within-network functional connectivity decreased one week after chemotherapy and increased six months after chemotherapy. As for the between-network functional connectivity, the posterior DMN-SMN connectivity showed the same tendency. These within- and between-network functional connectivity changes were associated with blood biochemical indexes and cognitive assessment scores. Conclusions These results indicated that network-level connectivity alterations may serve as a potential biomarker of chemotherapy related cognitive impairment, providing insights for further functional recovery treatment.