Werner Bonnita, Warton Kristina, Ford Caroline E
Gynaecological Cancer Research Group, School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia.
Cancers (Basel). 2022 Mar 3;14(5):1309. doi: 10.3390/cancers14051309.
Cell-free DNA (cfDNA) is a useful molecular biomarker in oncology research and treatment, but while research into its properties in blood has flourished, there remains much to be discovered about cfDNA in other body fluids. The cfDNA from saliva, sputum, cerebrospinal fluid, urine, faeces, pleural effusions, and ascites has unique advantages over blood, and has potential as an alternative 'liquid biopsy' template. This review summarises the state of current knowledge and identifies the gaps in our understanding of non-blood liquid biopsies; where their advantages lie, where caution is needed, where they might fit clinically, and where research should focus in order to accelerate clinical implementation. An emphasis is placed on ascites and pleural effusions, being pathological fluids directly associated with cancer. We conclude that non-blood fluids are viable sources of cfDNA in situations where solid tissue biopsies are inaccessible, or only accessible from dated archived specimens. In addition, we show that due to the abundance of cfDNA in non-blood fluids, they can outperform blood in many circumstances. We demonstrate multiple instances in which DNA from various sources can provide additional information, and thus we advocate for analysing non-blood sources as a complement to blood and/or tissue. Further research into these fluids will highlight opportunities to improve patient outcomes across cancer types.
游离DNA（cfDNA）是肿瘤学研究和治疗中一种有用的分子生物标志物。虽然对其在血液中的特性研究蓬勃发展，但关于其他体液中的cfDNA仍有许多有待发现之处。唾液、痰液、脑脊液、尿液、粪便、胸腔积液和腹水中的cfDNA相对于血液具有独特优势，具有作为替代“液体活检”模板的潜力。本综述总结了当前的知识状态，确定了我们在理解非血液液体活检方面的差距；它们的优势所在、需要谨慎之处、在临床上的适用情况以及为加速临床应用研究应关注的重点。重点关注腹水和胸腔积液，它们是与癌症直接相关的病理性液体。我们得出结论，在无法获取实体组织活检或只能从陈旧存档标本获取活检的情况下，非血液体液是cfDNA的可行来源。此外，我们表明，由于非血液体液中cfDNA含量丰富，它们在许多情况下可以优于血液。我们展示了多个实例，其中来自各种来源的DNA可以提供额外信息，因此我们主张分析非血液来源作为对血液和/或组织的补充。对这些体液的进一步研究将凸显改善各类癌症患者治疗效果的机会。
