Objective:To investigate the alterations in brain functional activity before and after chemotherapy in breast cancer patients with chemotherapy-related cognitive impairment (CRCI) using resting-state functional magnetic resonance imaging (rs-fMRI) and their relations with cognitive impairment.Methods:A prospective observational study was performed; female breast cancer patients with CRCI admitted to Department of Oncology, Affiliated Hospital 6 of Nantong University were recruited, and age- and education level-matched female healthy controls were chosen. Before and one month after chemotherapy, statuses of cognitive function, depression and anxiety in breast cancer patients with CRCI were evaluated by Montreal cognitive assessment (MoCA), functional assessment of cancer therapy-cognitive function (FACT-cog), self-rating depression scale (SDS), and self-rating anxiety scale (SAS); subsequently, conventional MRI and resting-state functional magnetic resonance imaging (rs-fMRI) were conducted. The healthy controls accepted MoCA, SDS, and SAS, followed by conventional MRI and rs-fMRI. Differences in clinical data and amplitude of low-frequency fluctuation (ALFF, rs-fMRI brain spontaneous neural activity index) were compared between breast cancer patients with CRCI before chemotherapy and healthy controls, and in the breast cancer patients with CRCI between before and after chemotherapy. Taking the brain regions with significant differences in ALFF before and after chemotherapy in breast cancer patients with CRCI as seed points, the difference in whole-brain functional connectivity (FC) before and after chemotherapy was compared in breast cancer patients with CRCI. Pearson or Spearman correlation tests were used to analyze the correlations of ALFF and FC in brain regions with significant differences in ALFF with cognitive function scores in breast cancer patients with CRCI.Results:(1) A total of 22 breast cancer patients with CRCI and 22 healthy controls were enrolled. Compared with the healthy controls, the breast cancer patients with CRCI before chemotherapy had significantly higher SDS and SAS scores ( P<0.05). Compared with breast cancer patients with CRCI before chemotherapy, the breast cancer patients with CRCI after chemotherapy had significantly lower MoCA, FACT-cog-perceived cognitive impairment, FACT-cog-comment from others on cognitive function, and FACT-cog-perceived cognitive ability ( P<0.05). (2) Compared with those before chemotherapy, breast cancer patients with CRCI after chemotherapy exhibited significantly increased ALFF in the right precuneus, right middle occipital gyrus, and left superior frontal gyrus, while statistically decreased FC in the right middle occipital gyrus-left middle temporal gyrus, right precentral gyrus-right middle temporal gyrus, and left superior frontal gyrus-left fusiform gyrus ( P<0.05). (3) ALFF in the right precentral gyrus in breast cancer patients with CRCI after chemotherapy was negatively correlated with difference value of FACT-cog before and after chemotherapy ( r=-0.497, P=0.018) and difference value of PCA before and after chemotherapy ( r s=-0.436, P=0.042); FC in the left superior frontal gyrus-left fusiform gyrus was positively correlated with score of FACT-cog-perceived cognitive impairment ( r=0.621, P=0.002). Conclusion:Chemotherapy induces compensatory enhancement of spontaneous neural activity in multiple brain regions in breast cancer patients with CRCI, accompanied by FC disruption at specific brain areas, which are associated with cognitive impairment.

Objective:To investigate the alterations in brain functional activity before and after chemotherapy in breast cancer patients with chemotherapy-related cognitive impairment (CRCI) using resting-state functional magnetic resonance imaging (rs-fMRI) and their relations with cognitive impairment.Methods:A prospective observational study was performed; female breast cancer patients with CRCI admitted to Department of Oncology, Affiliated Hospital 6 of Nantong University were recruited, and age- and education level-matched female healthy controls were chosen. Before and one month after chemotherapy, statuses of cognitive function, depression and anxiety in breast cancer patients with CRCI were evaluated by Montreal cognitive assessment (MoCA), functional assessment of cancer therapy-cognitive function (FACT-cog), self-rating depression scale (SDS), and self-rating anxiety scale (SAS); subsequently, conventional MRI and resting-state functional magnetic resonance imaging (rs-fMRI) were conducted. The healthy controls accepted MoCA, SDS, and SAS, followed by conventional MRI and rs-fMRI. Differences in clinical data and amplitude of low-frequency fluctuation (ALFF, rs-fMRI brain spontaneous neural activity index) were compared between breast cancer patients with CRCI before chemotherapy and healthy controls, and in the breast cancer patients with CRCI between before and after chemotherapy. Taking the brain regions with significant differences in ALFF before and after chemotherapy in breast cancer patients with CRCI as seed points, the difference in whole-brain functional connectivity (FC) before and after chemotherapy was compared in breast cancer patients with CRCI. Pearson or Spearman correlation tests were used to analyze the correlations of ALFF and FC in brain regions with significant differences in ALFF with cognitive function scores in breast cancer patients with CRCI.Results:(1) A total of 22 breast cancer patients with CRCI and 22 healthy controls were enrolled. Compared with the healthy controls, the breast cancer patients with CRCI before chemotherapy had significantly higher SDS and SAS scores ( P<0.05). Compared with breast cancer patients with CRCI before chemotherapy, the breast cancer patients with CRCI after chemotherapy had significantly lower MoCA, FACT-cog-perceived cognitive impairment, FACT-cog-comment from others on cognitive function, and FACT-cog-perceived cognitive ability ( P<0.05). (2) Compared with those before chemotherapy, breast cancer patients with CRCI after chemotherapy exhibited significantly increased ALFF in the right precuneus, right middle occipital gyrus, and left superior frontal gyrus, while statistically decreased FC in the right middle occipital gyrus-left middle temporal gyrus, right precentral gyrus-right middle temporal gyrus, and left superior frontal gyrus-left fusiform gyrus ( P<0.05). (3) ALFF in the right precentral gyrus in breast cancer patients with CRCI after chemotherapy was negatively correlated with difference value of FACT-cog before and after chemotherapy ( r=-0.497, P=0.018) and difference value of PCA before and after chemotherapy ( r s=-0.436, P=0.042); FC in the left superior frontal gyrus-left fusiform gyrus was positively correlated with score of FACT-cog-perceived cognitive impairment ( r=0.621, P=0.002). Conclusion:Chemotherapy induces compensatory enhancement of spontaneous neural activity in multiple brain regions in breast cancer patients with CRCI, accompanied by FC disruption at specific brain areas, which are associated with cognitive impairment.