提取肺癌小活检标本固定液中的DNA进行EGFR突变检测的可行性分析

Investigation on the Possibility of EGFR Mutation Testing on DNA Extracted from Fixation Liquid of Lung Cancer Biopsy

背景与目的表皮生长因子受体(epidermal growth factor receptor, EGFR)突变是非小细胞肺癌(nonsmall cell lung cancer, NSCLC)患者中最常见的基因突变类型,很多国际指南推荐晚期NSCLC在治疗前先进行EGFR突变检测,本研究探讨提取肺癌小活检标本固定液中的DNA进行EGFR检测的可行性。方法收集取材后的肺癌小活检标本固定液,离心沉降后保存于-80 oC冰箱。提取DNA,采用ARMS法检测EGFR突变状态。对比患者石蜡包埋组织EGFR突变状态,分析两者之间的一致性、灵敏度及特异性。结果经临床检测石蜡包埋组织EGFR突变阳性28例及20例阴性病例中,其所配对的标本固定液中的分别检测出EGFR突变阳性20例和阴性20例,灵敏度及特异性分别为71.4%(20/28)和100.0%(20/20)。另外,同时检测了52例EGFR突变状态未知的石蜡包埋组织及配对的标本固定液,两种标本EGFR突变阳性率分别为36.5%(19/52)及28.8%(15/52),检测标本固定液的灵敏度及特异性分别为78.9%(15/19)和100.0%(33/33)。结论提取取材后标本固定液中的DNA可能是EGFR突变检测的一种可行的标本来源途径。

Background and objective Epidermal growth factor receptor(EGFR) mutation is the most common gene mutation in patients with non-small cell lung cancer(NSCLC). Many international guidelines are recommended to detected the EGFR mutation before the treatment of advanced non-small cell lung cancer. To investigate the possibility of EGFR mutation testing on DNA extracted from fixation liquid of lung cancer biopsy. Methods Fixation liquid of lung cancer biopsy was collected and stored at-80 oC after centrifugal. DNA was extracted and EGFR gene mutation was detected by ARMS. Compared with EGFR mutation status of paraffin-embedded tissues, the consistency, the sensitivity and specificity of EGFR mutation testing were analyzed. Results Among the 28 cases of EGFR mutation positive and 20 cases of EGFR mutation negative previously tested on paraffin-embedded tissue by clinic test, 20 cases with EGFR mutation positive and 20 cases with negative were detected by matched fixation liquid of lung cancer biopsy, respectively. The sensitivity and specificity were 71.4% and 100%. Moreover, 52 paraffin-embedded tissues and matched fixation liquid of lung cancer biopsy with unknown EGFR mutation status were detected, and the EGFR mutation positive rate were 36.5% and 28.8% respectively. The sensitivity and specificity of fixation liquid of lung cancer biopsy were 78.9% and 100.0%. Conclusion extracting the DNA from fixation liquid of lung cancer biopsy may be a kind of feasible way to detect EGFR mutation.