RESUMO
BACKGROUND@#Malignant plural effusion (MPE) is one of the most common specimen for liquid biopsy gene detection. This study aims to explore a method for isolating tumor cells from large volume of MPE and evaluate its efficacy and application prospect in gene detection.@*METHODS@#Pleural effusions (>500 mL) from 20 advanced lung cancer patients were obtained by effusion drainage and used to isolate tumor cells with cell separation media Percoll and Ficoll. Cell number and purity were calculated. DNA was extracted from the supernatant (etDNA), total cells and isolated tumor cells of pleural effusion (ETC-DNA) to detect the mutation of tumor-related genes by next-generation sequencing.@*RESULTS@#The median number of cells isolated from malignant pleural effusion was 8.50×10⁴ (interquel range: 9.25×10³-3.75×10⁵), 85.50%±5.80% of the cells were identified as tumor cells. The detection rates of epidermal growth factor receptor (EGFR) gene mutation of etDNA, total cell DNA and ETC-DNA were 70.00%, 50.00% and 70.00%, reseparately, while the median EGFR mutation abundance in 3 components was 16.05% (4.78%-43.06%), 1.09% (0.00%-2.39%), and 33.02% (18.50%-76.70%), respectively. ETC-DNA had good consistency with tissue DNA (P>0.999, kappa=1.000) and etDNA (P>0.999, kappa=1.000). ETC-DNA inclined to have higher EGFR mutation than etDNA, but the result was not statistically significant.@*CONCLUSIONS@#Our method can isolate large amount of tumor cells from a large volume of malignant pleural effusion with high purity. Using ETC-DNA as specimen improves the efficacy of gene detection, thus is worth further study.
RESUMO
BACKGROUND@#The detection of driver oncogenes of lung cancer is of great importance. There are various gene detection techniques nowadays which are different from each other. We carried out this study to investigate the specificity and sensitivity of assay panels based on an Amplification Refractory Mutation System-polymerase chain reaction (ARMS-PCR) technique of Amplification Mutation Specific System (AMSS) in detection of lung cancer gene mutation. To estimate the applicable value of assay panels in clinical settings.@*METHODS@#We collected cancer tissue specimens or fluid specimens from 309 patients. Mutation results were presented for those samples previously detected by ARMS-PCR. In comparison, we carried out AMSS-PCR using (epidermal growth factor receptor, EGFR) assay panel and Six-Alliance assay panel as well as Sanger sequencing. Software SPSS 22.0 (SPSS IBM) was used for statistical analysis.@*RESULTS@#The rates of consistency between the results by assay panels and Sanger sequencing or ARMS-PCR were 97.41% and 97.73%, respectively. Besides, EGFR assay panel had higher consistency rates with other detection methods than Six-Alliance assay panel. As for consistency test, the Kappa values of assay panels with Sanger sequencing, assay panels with ARMS-PCR, and ARMS-PCR with Sanger sequencing were 0.946, 0.953, and 0.913, respectively. The receiver operating characteristic curve (ROC) area under curve (AUC) of assay panels was 0.976 referring to Sanger sequencing, and 0.975 as ARMS-PCR was referred to.@*CONCLUSIONS@#AMSS-PCR can make an optimal cancer gene mutation detection method for clinical settings.