Introduction

Maximising alternative sample types for genomics in advanced lung cancer is important because bronchoscopic samples may sometimes be insufficient for this purpose. Further, the clinical applications of comprehensive molecular analysis such as whole genome sequencing (WGS) are rapidly developing. Diff-Quik cytology smears from EBUS TBNA is an alternative source of DNA, but its feasibility for WGS has not been previously demonstrated.

Methods

Diff-Quik smears were collected along with research cell pellets.

Results

Tumour content of smears were compared to research cell pellets from 42 patients, which showed good correlation (Spearman correlation 0.85, P < 0.0001). A subset of eight smears underwent WGS, which presented similar mutation profiles to WGS of the matched cell pellet. DNA yield was predicted using a regression equation of the smears cytology features, which correctly predicted DNA yield > 1500 ng in 7 out of 8 smears.

Conclusions

WGS of commonly collected Diff-Quik slides is feasible and their DNA yield can be predicted.

中文翻译：

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晚期肺癌的全基因组测序可以使用支气管内超声、经支气管针吸活检 (EBUS TBNA) 衍生的 Diff-Quik 细胞学涂片进行

介绍

最大限度地提高晚期肺癌基因组学的替代样本类型非常重要，因为支气管镜样本有时可能不足以达到此目的。此外，全基因组测序（WGS）等综合分子分析的临床应用正在迅速发展。EBUS TBNA 的 Diff-Quik 细胞学涂片是 DNA 的替代来源，但其用于全基因组测序的可行性此前尚未得到证实。

方法

Diff-Quik 涂片与研究细胞沉淀一起收集。

结果

将涂片的肿瘤含量与 42 名患者的研究细胞沉淀进行比较，显示出良好的相关性（Spearman 相关性 0.85，P  < 0.0001）。八张涂片的子集接受了全基因组测序，其突变谱与匹配细胞沉淀的全基因组测序相似。使用涂片细胞学特征的回归方程预测 DNA 产量，该方程正确预测了 8 个涂片中有 7 个的 DNA 产量 > 1500 ng。

结论

对常用收集的 Diff-Quik 载玻片进行全基因组测序 (WGS) 是可行的，并且可以预测其 DNA 产量。