组织活检是当前探索癌症分子景观的主要工具，但其还存在许多限制，常被执行的次数较低，过于侵入性且有副作用的风险。这些限制以及癌症不断演化其基因组特征的能力，最近已经导致了需要一种更非侵入性和更准确的替代方法，即液体活检。通过在体液中搜索循环肿瘤细胞及其核酸残留物或其他肿瘤产物，尤其是在血液中，但也包括尿液、粪便和唾液中，液体活检正在成为临床肿瘤学的未来。尽管目前还缺乏其工作流程的标准化，使其难以复制，但液体活检已经取得了癌症筛查、诊断、预后和复发风险方面的有希望的结果。通过对肿瘤的更易获取的分子特征进行分析，可以更容易地识别预测治疗反应的生物标志物，例如非小细胞肺癌中的EGFR突变和结直肠癌中的KRAS突变，或作为pembrolizumab反应的预测标志的微卫星不稳定性和错配修复。通过监测血液中循环肿瘤DNA的纵向重复采样，我们还可以预测已经进行了根治手术的患者的微少残留病和复发风险。在本综述中，我们将讨论液体活检的不同形式的限制和优势的当前认识，以及其在正常癌症管理中的应用，并简要介绍其最新的生物标志物及其未来的影响。© 2023. "Regina Elena" National Cancer Institute, Italy.

Tissue-based biopsy is the present main tool to explore the molecular landscape of cancer, but it also has many limits to be frequently executed, being too invasive with the risk of side effects. These limits and the ability of cancer to constantly evolve its genomic profile, have recently led to the need of a less invasive and more accurate alternative, such as liquid biopsy. By searching Circulating Tumor Cells and residues of their nucleic acids or other tumor products in body fluids, especially in blood, but also in urine, stools and saliva, liquid biopsy is becoming the future of clinical oncology. Despite the current lack of a standardization for its workflows, that makes it hard to be reproduced, liquid biopsy has already obtained promising results for cancer screening, diagnosis, prognosis, and risk of recurrence.Through a more accessible molecular profiling of tumors, it could become easier to identify biomarkers predictive of response to treatment, such as EGFR mutations in non-small cell lung cancer and KRAS mutations in colorectal cancer, or Microsatellite Instability and Mismatch Repair as predictive markers of pembrolizumab response.By monitoring circulating tumor DNA in longitudinal repeated sampling of blood we could also predict Minimal Residual Disease and the risk of recurrence in already radically resected patients.In this review we will discuss about the current knowledge of limitations and strengths of the different forms of liquid biopsies for its inclusion in normal cancer management, with a brief nod to their newest biomarkers and its future implications.© 2023. Italian National Cancer Institute ‘Regina Elena’.