Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York.
Robert J. Tomsich Pathology and Laboratory Medicine Institute, The Cleveland Clinic, Cleveland, Ohio.
Cancer Cytopathol. 2020 Nov;128(11):840-851. doi: 10.1002/cncy.22315. Epub 2020 Jun 29.
Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a sensitive and specific tool in the risk stratification of pancreatic lesions, including cysts. The sensitivity and specificity of EUS-FNA has been shown to improve when cytology is combined with next-generation sequencing (NGS). Ideally, fresh cyst fluid is used for NGS. In this pilot study, we explore the possibility of sequencing DNA derived from residual alcohol-fixed pancreatic aspirates.
Residual cytologic fixatives (n = 42) from 39 patients who underwent EUS-FNA for pancreatic lesions were collected along with demographics, imaging, and laboratory studies. Samples were designated as nonneoplastic/nonmucinous benign (NB), mucinous cyst (MC), pancreatic ductal adenocarcinoma (PDAC), or well-differentiated neuroendocrine tumor (NET) on the basis of cytopathologic evaluation and sequenced on the Oncomine platform (ThermoFisher Scientific, Waltham, Massachusetts).
Ten of 14 (71.4%) MCs exhibited clinically significant variants, including KRAS, GNAS, and TP53. Ten of 15 (66.7%) PDACs had KRAS alterations, and 9 of 15 (60%) showed variants in TP53. No variants were detected in any NETs. Only 1 of 9 (11.1%) NB aspirates showed variants in KRAS and MAP2K. Sequencing of formalin-fixed, paraffin-embedded tissue revealed variants identical to those detected in fixative-derived DNA in 4 of 5 cases (80%).
Residual DNA from alcohol-fixed aspirates are an underutilized source for NGS. Sequencing residual fixative-derived DNA has the potential to be integrated into the workup of pancreatic aspirates, possibly impacting management.
内镜超声引导下细针抽吸术（EUS-FNA）是一种敏感且特异的工具，可用于对胰腺病变（包括囊肿）进行风险分层。当细胞学与下一代测序（NGS）相结合时，EUS-FNA 的敏感性和特异性得到了提高。理想情况下，使用新鲜的囊液进行 NGS。在这项初步研究中，我们探索了从残留的酒精固定的胰腺抽吸物中提取 DNA 进行测序的可能性。
收集了 39 名因胰腺病变而行 EUS-FNA 的患者的残留细胞固定液（n=42），并记录了人口统计学、影像学和实验室研究资料。根据细胞病理学评估，将样本分为非肿瘤/非黏液性良性（NB）、黏液性囊腺瘤（MC）、胰腺导管腺癌（PDAC）或分化良好的神经内分泌肿瘤（NET），并在 Oncomine 平台（ThermoFisher Scientific，马萨诸塞州沃尔瑟姆）上进行测序。
14 个 MC 中有 10 个（71.4%）表现出具有临床意义的变异，包括 KRAS、GNAS 和 TP53。15 个 PDAC 中有 10 个（66.7%）发生 KRAS 改变，9 个（60%）显示 TP53 变异。NET 中未检测到任何变异。9 个 NB 抽吸物中只有 1 个（11.1%）显示 KRAS 和 MAP2K 变异。对福尔马林固定、石蜡包埋组织进行测序显示，在 5 例中有 4 例（80%）与固定液衍生 DNA 中检测到的变异完全相同。
从酒精固定抽吸物中提取的残留 DNA 是 NGS 未充分利用的来源。对残留固定液衍生 DNA 进行测序有可能被纳入胰腺抽吸物的检测中，从而可能影响治疗决策。
