Multiplexed Molecular Profiling of Lung Cancer Using Pleural Effusion

Introduction: Pleural effusion is frequently observed in patients with advanced lung cancer. Although effusion can be obtained less invasively and repeatedly, its use in multiplexed molecular profiling has not been fully investigated. Methods: Between July 2011 and April 2013, pleural effusion samples were obtained from patients with lung cancer at Shizuoka Cancer Center. They were analyzed for EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN, and HER2 mutations, EGFR, MET, FGFR1, FGFR2, and PIK3CA amplifications, and ALK, ROS1, and RET fusion genes using pyrosequensing and/or capillary electrophoresis, quantitative reverse-transcriptase polymerase chain reaction, and reverse-transcriptase polymerase chain reaction, respectively. Results: One hundred and two samples from 84 patients were analyzed. Adenocarcinoma was the most common histological subtype (82%). Genetic abnormalities were detected in 42% of patients. The most common abnormality was EGFR mutation (29%), followed by EML4-ALK rearrangement (5%), KRAS mutation, and EGFR amplification (4%, each). Concordance rates between pleural effusion and matched formalin-fixed, paraffin-embedded samples were 88%. Among 11 patients who provided samples at multiple time points, changes in molecular profile over the course of treatment were observed in five patients. Conclusions: The use of pleural effusion for multiplexed molecular testing and real-time monitoring in lung cancer was demonstrated.