Bellevicine Claudio, Malapelle Umberto, Vigliar Elena, de Luca Caterina, Troncone Giancarlo
Pathology Section, Department of Public Health, University of Naples Federico II, Naples, Italy.
Acta Cytol. 2014;58(6):589-94. doi: 10.1159/000369756. Epub 2014 Nov 22.
In this study we reviewed our practice of lung cancer epidermal growth factor receptor (EGFR) mutational testing in an academic centralized laboratory setting, where direct smears and liquid-based cytology (LBC) slides represent the most frequent cytological specimens received. The aim was to assess the differences, if any, between these sample types in terms of DNA yield, adequacy rates and overall EGFR testing performance.
A total of 362 cases were retrieved - received from January 2012 to January 2014 for EGFR testing - including 204 LBC specimens and 158 smears. Exon 19 deletions and the L858R point mutation in exon 21, detected by fragment assay and TaqMan assay, respectively, were confirmed by direct sequencing or by high-resolution melting.
Although the direct smears showed a higher DNA yield (60.94 vs. 23.07 ng/µl) and were more frequently cell-rich (54%) than the LBC slides (31.4%), the differences in adequacy (direct smears: 97.4%; LBCs: 94.1%) and in mutant rate (direct smears: 10.3%; LBCs: 14.0%) between the two sample types did not reach statistical significance.
Not only direct smears but also LBC slides represent an effective preparation and storage medium for cytological material to be used for EGFR molecular testing.
在本研究中，我们回顾了在学术性集中实验室环境下进行肺癌表皮生长因子受体（EGFR）突变检测的实践，其中直接涂片和液基细胞学（LBC）玻片是最常收到的细胞学标本。目的是评估这些样本类型在DNA产量、充足率和整体EGFR检测性能方面是否存在差异。
共检索到362例病例——于2012年1月至2014年1月接收用于EGFR检测——包括204例LBC标本和158例涂片。分别通过片段分析和TaqMan分析检测到的外显子19缺失和外显子21中的L858R点突变，通过直接测序或高分辨率熔解进行确认。
尽管直接涂片显示出更高的DNA产量（60.94对23.07 ng/µl），且细胞丰富的频率（54%）高于LBC玻片（31.4%），但两种样本类型在充足率（直接涂片：97.4%；LBC：94.1%）和突变率（直接涂片：10.3%；LBC：14.0%）方面的差异未达到统计学意义。
不仅直接涂片，LBC玻片也是用于EGFR分子检测的细胞学材料的有效制备和储存介质。
