a Department of Psychology & Behavioural Sciences, Unit for Psycho-Oncology & Health Psychology , Aarhus University , Aarhus , Denmark.
b Department of Medical Social Sciences , Northwestern University Feinberg School of Medicine , Chicago , IL , USA.
Acta Oncol. 2019 May;58(5):522-536. doi: 10.1080/0284186X.2018.1563716. Epub 2019 Feb 7.
Cancer and cancer treatments may impact the brain through several pathways leading to cognitive impairment. Neuroimaging evidence has begun to elucidate the neurobiological underpinnings of cancer-related cognitive impairment. The aim of this paper was to systematically review available literature on structural brain alterations following adult non-central nervous system (CNS) cancers and associated treatments. This review followed PRISMA guidelines and was registered in PROSPERO (ID#107387). Comprehensive searches were conducted in June 2018 using PubMed and Web of Science. Inclusion criteria were English peer-reviewed journal articles of formal, controlled studies that examined structural neuroimaging outcomes in adult non-CNS cancer patients and survivors. Selected articles were assessed for quality and risk of bias using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Thirty-six publications of prospective and cross-sectional studies met inclusion criteria and were included. Structural brain alterations following cancer and its treatment were reported in a majority of the publications as evidenced by reduced global and local gray matter volumes, impaired white matter microstructural integrity, and brain network alterations. Structural alterations were most often evident when cancer-treated groups were compared with healthy controls, and more subtle when compared with cancer controls. Regarding the existence of pretreatment impairments, the evidence was equivocal. There was significant between-study heterogeneity in imaging analytical approaches and use of statistical adjustments. Over half reported associations with cognitive outcomes, though regions and associated cognitive domains were heterogeneous. Structural brain alterations following cancer and cancer treatments were reported in a majority of the reviewed studies. However, the extent of observed alterations depended on the choice of comparison groups. Methodological issues exist that will need to be addressed systematically to ensure the validity of findings. Large-scale prospective studies with extended assessment points are warranted to replicate and build upon initial findings.
癌症及其治疗方法可能通过多种途径影响大脑，导致认知障碍。神经影像学证据已经开始阐明与癌症相关的认知障碍的神经生物学基础。本文的目的是系统地回顾成人非中枢神经系统（CNS）癌症及其相关治疗后结构脑改变的现有文献。本综述遵循 PRISMA 指南，并在 PROSPERO（ID#107387）中进行了注册。2018 年 6 月，使用 PubMed 和 Web of Science 进行了全面检索。纳入标准为正式、对照研究的英文同行评议期刊文章，这些研究检查了成人非 CNS 癌症患者和幸存者的结构神经影像学结果。使用 NIH 观察性队列和横断面研究质量评估工具评估选定文章的质量和偏倚风险。有 36 篇前瞻性和横断面研究的出版物符合纳入标准并被纳入。大多数出版物都报告了癌症及其治疗后的结构脑改变，表现为全脑和局部灰质体积减少、白质微观结构完整性受损以及脑网络改变。当将癌症治疗组与健康对照组进行比较时，结构改变最为明显，而与癌症对照组进行比较时则更为微妙。关于预处理损伤的存在，证据尚无定论。在成像分析方法的使用和统计调整方面存在显著的研究间异质性。超过一半的研究报告了与认知结果的相关性，尽管区域和相关认知领域存在异质性。大多数综述研究报告了癌症和癌症治疗后的结构脑改变。然而，观察到的改变程度取决于比较组的选择。存在方法学问题，需要系统地解决这些问题，以确保研究结果的有效性。需要进行大规模的前瞻性研究，并延长评估点，以复制和扩展初始发现。
