"Liquid Biopsy" in Liver Cancer

肝癌是全球第二大癌症相关死亡原因。关于决策和分期，临床实践指南(CPG)仅依赖于巴塞罗那肝癌诊所(BCLC)算法中包含的临床和/或病理参数，但不包含任何肿瘤的生物学读数，例如分子读数。仍然有一些临床情况不能通过当前的算法准确地捕捉预后，例如术前识别手术后的肿瘤复发，以及预测治疗对系统治疗的反应。在过去的十年中，肝细胞癌的遗传格局已经被发现，包括点状体细胞突变、染色体重排和基因表达失控。此外，最近的证据表明，肝细胞癌内存在显著的分子异质性，这可能限制了来自单个组织活检的分子信息。“液体活组织检查”的概念是为了便于从肿瘤中收集分子信息，并捕捉不同样本中存在的改变的整个图景。液体活检包括分离和分析肿瘤副产物，主要是无细胞核酸和循环中的肿瘤细胞(CTC)，释放到血液中，在外周血液中很容易获得。比癌症分子图景的基线快照更有趣的是，循环生物标记物允许随着疾病的发展和患者暴露于不同的医疗干预措施而对肿瘤遗传学进行连续评估。结合基线基因组异常的分析，循环核酸将成为临床实践中轻松和非侵入性监测癌症过程的无与伦比的工具。这项为期两年的翻译研究计划的总体目标是通过定义循环分子生物标记物的预后/预测作用来解决肝癌治疗中的核心问题。已经从165名肝细胞癌患者(25名配对组织)的不同疾病和治疗阶段采集了血液样本，包括对同一患者的连续采集。利用最新的基因组方法(如深度测序、偶联FACS排序和单细胞测序)，我们将评估a)血浆DNA中高频突变基因子集的体细胞突变，b)RNA表达谱和c)肝细胞癌患者的CTC。我们还将把分子浆数据与两种成分都可用的患者的配对组织联系起来。循环标志物将与其他临床变量一起进行评估，以最大限度地提高肝细胞癌预后预测的准确性(即肿瘤复发和总存活率)。最终，我们的目标是为在肝癌患者的决策中实施分子监测提供科学依据。

Liver cancer is the second cause of cancer-related death worldwide. Regarding decision-making and staging, Clinical Practice Guidelines (CPG) only rely on clinical and / or pathological parameters encapsulated in the Barcelona Clinic for Liver Cancer (BCLC) algorithm, but do not incorporate any biological, e.g. molecular, readout of the tumor. There are still clinical situations where prognosis is not accurately captured by current algorithms such as preoperative identification of tumor recurrence after surgery, and prediction of treatment response to systemic therapy. The genetic landscape of hepatocellular carcinoma (HCC) has been uncovered over the last decade, including point somatic mutations, chromosomal rearrangements and gene expression de-regulation. In addition, recent evidence suggests a significant molecular heterogeneity within HCC, which may limit molecular information derived from a single tissue biopsy. The concept of “liquid biopsy” was developed to facilitate the collection of molecular information from the tumor, and to capture the entire landscape of alterations present in heterogeneous samples. Liquid biopsy comprise the isolation and analysis of tumor by-products, mainly cell-free nucleic acids and circulating tumor cells (CTC), released to the bloodstream and easily accessible in peripheral blood. Even more interesting than a baseline snapshot of the molecular landscape of cancer, circulating biomarkers allow for a sequential evaluation of tumor genetics as the disease evolves and when the patient is exposed to different medical interventions. Coupled with the analysis of baseline genome aberrations, circulating nucleic acids will be an unparalleled tool to easily and non-invasively monitor the course of cancer in clinical practice.The overall objective of this two-year translational research initiative is to solve core problems in liver cancer management by defining the prognostic / predictive role of circulating molecular biomarkers. Blood samples have already been collected from 165 HCC patients (25 with paired tissue) at different stages of disease and treatment, including sequential collection in the same patient. Using latest genomic methodologies (e.g. deep-sequencing, coupled FACS sorting and single-cell sequencing), we will assess a) somatic mutations in a subset of high-frequency mutated genes in plasmatic DNA, b) RNA expression profiles and c) CTC in HCC patients. We will also correlate molecular plasmatic data with paired tissue in those patients with both components available. Circulating markers will be assessed along other clinical variables to maximize the accuracy of outcome prediction in HCC (i.e., tumor recurrence and overall survival). Ultimately, our aim is to provide the scientific ground to implement molecular monitoring in decision-making for liver cancer patients.