Background or Purpose

Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). However, the diagnostic adequacy of EUS-FNA is often limited by low cellularity leading to inconclusive results. We aimed to investigate the feasibility and added utility of targeted next-generation sequencing (NGS) on PDAC EUS-FNAs.

Methods

EUS-FNAs were prospectively performed on 59 patients with suspected PDAC (2014-2017) at a high-volume center. FNAs were analyzed for the presence of somatic mutations using NGS to supplement cytopathologic evaluations and were compared to surgical specimens and circulating tumor DNA (ctDNA).

Results

Fifty-nine patients with suspected PDAC were evaluated, and 52 were diagnosed with PDAC on EUS-FNA. Four of the remaining seven patients had inconclusive EUS-FNAs and were ultimately diagnosed with PDAC after surgical resection. Of these 56 cases of PDAC, 48 (85.7%) and 18 (32.1%) harbored a KRAS and/or TP53 mutation on FNA NGS, respectively. Particularly, in the four inconclusive FNA PDAC diagnoses (false negatives), half harbored KRAS mutations on FNA. No KRAS/TP53 mutation was found in remaining three non-PDAC cases. All EUS-FNA detected KRAS mutations were detected in 16 patients that underwent primary tumor NGS (100% concordance), while 75% KRAS concordance was found between FNA and ctDNA NGS.

Conclusion

Targeted NGS can reliably detect KRAS mutations from EUS-FNA samples and exhibits high KRAS mutational concordance with primary tumor and ctDNA. This suggests targeted NGS of EUS-FNA samples may enable preoperative ctDNA prognostication using digital droplet PCR and supplement diagnoses in patients with inconclusive EUS-FNA.

中文翻译：

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在内窥镜超声引导下使用下一代测序的细针穿刺可靠检测胰腺癌的体细胞突变：前瞻性队列研究的意义

背景或目的

胰腺导管腺癌 (PDAC) 通常通过内镜超声引导细针穿刺 (EUS-FNA) 进行诊断。然而，EUS-FNA 的诊断充分性通常受到低细胞数量的限制，导致结果不确定。我们旨在研究靶向下一代测序 (NGS) 在 PDAC EUS-FNA 上的可行性和附加效用。

方法

EUS-FNA 在一个高容量中心对 59 名疑似 PDAC 的患者（2014-2017 年）进行了前瞻性研究。使用 NGS 分析 FNA 是否存在体细胞突变，以补充细胞病理学评估，并与手术标本和循环肿瘤 DNA (ctDNA) 进行比较。

结果

对 59 名疑似 PDAC 的患者进行了评估，其中 52 名在 EUS-FNA 上被诊断出患有 PDAC。其余 7 名患者中有 4 名具有不确定的 EUS-FNA，并在手术切除后最终被诊断出患有 PDAC。在这 56 例 PDAC 中，分别有 48 (85.7%) 和 18 (32.1%)在 FNA NGS 上携带KRAS和/或TP53突变。特别是，在四个不确定的 FNA PDAC 诊断（假阴性）中，一半在 FNA 上携带KRAS突变。没有KRAS / TP53突变，在其余三个非PDAC病例发现。在接受原发肿瘤 NGS 的 16 名患者中检测到所有 EUS-FNA 检测到的KRAS突变（100% 一致），而 75% KRAS 在 FNA 和 ctDNA NGS 之间发现了一致性。

结论

靶向 NGS 可以可靠地检测EUS-FNA 样本中的KRAS突变，并显示出与原发肿瘤和 ctDNA 的高KRAS突变一致性。这表明 EUS-FNA 样本的靶向 NGS 可以使用数字液滴 PCR 进行术前 ctDNA 预测，并补充对不确定的 EUS-FNA 患者的诊断。