Second Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan.
Dig Endosc. 2022 Nov;34(7):1329-1339. doi: 10.1111/den.14344. Epub 2022 Jun 12.
Endoscopic ultrasound-guided tissue acquisition (EUS-TA) currently plays a central role in the diagnosis of pancreatic ductal adenocarcinoma (PDAC). Although fine-needle aspiration has been the gold standard, novel biopsy needles for fine-needle biopsy (FNB) were developed to overcome its limitations, which include low tumor cellularity and the inability to retain cellular architecture. Following recent improvements in FNB needles, the pathological diagnosis has shifted from cytology to histology and now to genetic diagnosis. Genetic analysis using EUS-TA samples began with a search for the presence of K-ras mutations. However, the introduction of next-generation sequencers has dramatically changed genetic analysis and led to the gradual elucidation of the mechanism of PDAC, enabling personalized medicine by performing multiple gene analyses simultaneously. Comprehensive genomic profiling is currently applied in the clinical setting and there is an increasing need for gene analysis using EUS-TA samples. Although target genome sequencing is feasible even with cytological specimens, it can be difficult to proceed with full genetic analysis including whole-exome sequence or whole-genome sequence if the samples are too small. Genetic analysis will become highly important in determining indications for personalized medicine such as poly (ADP-ribose) polymerase inhibitors or immune checkpoint inhibitors. Therefore, the endosonographer must always take gene analysis into consideration when collecting samples for diagnosis and further improvement of the puncture technique and needle development are anticipated in the future.
内镜超声引导下组织获取（EUS-TA）目前在胰腺导管腺癌（PDAC）的诊断中发挥着核心作用。虽然细针穿刺一直是金标准，但为了克服其局限性，新型细针活检（FNB）活检针已被开发出来，其局限性包括肿瘤细胞数量低和无法保留细胞结构。在 FNB 针最近得到改进后，病理诊断已从细胞学转变为组织学，现在又转变为基因诊断。使用 EUS-TA 样本进行基因分析始于寻找 K-ras 突变的存在。然而，下一代测序仪的引入极大地改变了基因分析，并逐步阐明了 PDAC 的发病机制，通过同时进行多个基因分析实现了个性化医疗。综合基因组分析目前已在临床环境中应用，并且对使用 EUS-TA 样本进行基因分析的需求也在不断增加。尽管即使使用细胞学标本也可以进行靶向基因组测序，但如果标本太小，则很难进行包括全外显子组序列或全基因组序列在内的完整基因分析。基因分析将在确定个性化医学的适应症方面变得非常重要，例如多聚（ADP-核糖）聚合酶抑制剂或免疫检查点抑制剂。因此，当采集用于诊断的样本时，超声内镜医师必须始终考虑基因分析，并且预计未来穿刺技术和针具的进一步改进。
