School of Medicine, Chang Gung University, Taoyuan, Taiwan.
Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan.
PLoS One. 2020 May 4;15(5):e0232548. doi: 10.1371/journal.pone.0232548. eCollection 2020.
Treatment modalities for breast cancer, the leading cause of cancer-related deaths in women worldwide, include surgery, radiotherapy, adjuvant chemotherapy, targeted therapy, and hormonal therapy. The advancement in medical technology has facilitated substantial reduction in breast cancer mortality. However, patients may experience cognitive impairment after chemotherapy. This phenomenon called chemotherapy-induced cognitive impairment (i.e., "chemobrain") is common among breast cancer survivors. However, cognitive function deficits may exist before chemotherapy initiation. This study examined the functional network alterations in breast survivors by using resting-state functional magnetic resonance imaging (fMRI).
We recruited 172 female participants and separated them into three groups: C+ (57 breast cancer survivors who had finished 3-12-month-long chemotherapy), C- (45 breast cancer survivors who had not undergone chemotherapy), and HC (70 participants with no breast cancer history). We analyzed mean fractional amplitudes of low-frequency fluctuation and graph theoretical topologies from resting-state fMRI and applied network-based analysis to portray functional changes among the three groups.
Among the three groups, the C- group demonstrated hyperactivity in the prefrontal cortex, bilateral middle temporal gyrus, right inferior temporal gyrus and right angular gyrus. Only the left caudate demonstrated significantly more hypoactivity in the C- group than in the C+ group. Graph theoretical analysis demonstrated that the brains of the C+ group became inclined toward regular networks and the brains of the C- group became inclined toward random networks.
Subtle alterations were noted in the brain activity and networks of our cancer survivors. Moreover, functional network disruptions occurred regardless of chemotherapeutic agent administration.
乳腺癌是全球女性癌症相关死亡的主要原因，其治疗方法包括手术、放疗、辅助化疗、靶向治疗和激素治疗。医疗技术的进步极大地降低了乳腺癌的死亡率。然而，患者在化疗后可能会出现认知障碍。这种现象称为化疗引起的认知障碍（即“化疗脑”），在乳腺癌幸存者中很常见。然而，在开始化疗之前，认知功能可能已经存在缺陷。本研究通过静息态功能磁共振成像（rs-fMRI）研究了乳腺癌幸存者的功能网络改变。
我们招募了 172 名女性参与者，并将她们分为三组：C+（57 名完成了 3-12 个月化疗的乳腺癌幸存者）、C-（45 名未接受化疗的乳腺癌幸存者）和 HC（70 名无乳腺癌病史的参与者）。我们分析了静息态 fMRI 的平均低频振幅和图论拓扑结构，并应用基于网络的分析方法来描述三组之间的功能变化。
在三组中，C-组表现出前额叶皮层、双侧颞中回、右侧颞下回和右侧角回的活动过度。只有左侧尾状核在 C-组中比 C+组表现出明显更多的活动不足。图论分析表明，C+组的大脑倾向于规则网络，而 C-组的大脑倾向于随机网络。
我们发现癌症幸存者的大脑活动和网络存在细微改变。此外，无论是否使用化疗药物，功能网络的破坏都会发生。
