BACKGROUND AND AIMS The sensitivity of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for diagnosing the recurrence of pancreatic cancer is usually low because of difficulties in obtaining adequate samples for pathological examinations. We evaluated the efficacy of highly sensitive KRAS mutation analysis using EUS-FNA washes to detect cancer recurrence. METHODS Nineteen consecutive patients with suspected pancreatic cancer recurrence after surgical resection were enrolled. All underwent EUS-FNA, and samples were obtained for pathological examination. After the first session, the inside of the FNA needle was washed with saline for DNA extraction. KRAS mutations were examined using digital droplet PCR (dPCR). RESULTS The median needle puncture number used to obtain adequate pathological samples was two (range 1-6). In ten patients pathologically diagnosed with malignant pancreatic cancer, nine patients tested positive for a KRAS mutation. All patients who were not diagnosed with a malignant pancreatic cancer tested negative for a KRAS mutation. About half of surgically resected primary cancers (9/19) showed double KRAS mutations (G12V and G12D); however, all but one wash sample showed a single KRAS mutation, G12D. After including one patient who showed a malignant recurrence during follow-up, the sensitivities of a pathological diagnosis and KRAS analysis to detect recurrence were 90.9% and 81.8%, respectively. CONCLUSIONS KRAS mutation analysis of needle wash samples using dPCR is a new methodology for the diagnosis of the local recurrence of pancreatic cancer. The diagnostic ability of dPCR with a one-time needle wash sample was comparable to a pathological diagnosis with multiple samplings.

中文翻译：

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通过使用内镜超声引导下的细针抽吸冲洗液进行KRAS突变分析，评估胰腺癌的局部复发。

背景与目的内镜超声引导下细针穿刺抽吸术（EUS-FNA）诊断胰腺癌复发的敏感性通常很低，因为难以获得足够的病理检查样本。我们评估了使用EUS-FNA清洗检测癌症复发的高灵敏度KRAS突变分析的功效。方法纳入19例手术切除后疑似胰腺癌复发的患者。所有患者均进行了EUS-FNA，并获得了样本进行病理检查。在第一阶段之后，用盐水洗涤FNA针的内部，以提取DNA。使用数字液滴PCR（dPCR）检查了KRAS突变。结果用于获得足够的病理学样本的中位数穿刺次数为2（范围1-6）。在经病理诊断为恶性胰腺癌的十名患者中，有九名患者的KRAS突变检测为阳性。所有未诊断为恶性胰腺癌的患者的KRAS突变均呈阴性。约有一半的手术切除原发癌（9/19）显示出双重的KRAS突变（G12V和G12D）。然而，除一个洗涤样品外，所有样品均显示出一个单一的KRAS突变G12D。纳入一名在随访期间显示恶性复发的患者后，病理诊断和KRAS分析检测复发的敏感性分别为90.9％和81.8％。结论使用dPCR对针洗样品进行KRAS突变分析是诊断胰腺癌局部复发的一种新方法。