Suitability of Frozen Pleural Fluid Pellets for Next-Generation Sequencing-Based Driver Gene Testing in Non-Small Cell Lung Cancer.

Background: Driver gene alterations are increasingly being identified, and multiplex genetic tests have become essential for determining the optimal treatment method for advanced non-small cell lung cancer (NSCLC). Next-generation sequencing (NGS) enables the simultaneous detection of multiple driver gene alterations using nucleic acids extracted from tumor tissue samples. However, obtaining sufficient tumor tissue volume is challenging, and inadequate formalin fixation can lead to the failure of NGS analysis. Malignant pleural effusions can be collected using a simple, minimally invasive technique; however, it remains uncertain whether pleural fluid is a suitable source for detecting driver gene alterations using NGS. This retrospective observational study examined the suitability of fresh-frozen pleural fluid pellets for NGS in clinical practice.

Methods: Patients with NSCLC whose frozen pleural fluid pellets were analyzed using the Oncomine Dx Target Test Multi-CDx System between June 2019 and February 2024 were included in the study. The primary endpoint was the success rate of driver gene analysis.

Results: In total, 26 patients were enrolled. The success rate for testing alterations in driver genes was 92.3% (24/26), and the detection rate of targetable driver gene alterations was 53.8% (14/26). The median turnaround time from sample submission to result confirmation was 10 days (range 7-19 days).

Conclusion: Our findings indicate that frozen pleural fluid pellets are suitable for NGS-based driver gene testing in patients with advanced NSCLC. This approach provides a practical alternative for multigene testing when sufficient tissue is not available.