Reference: April 2026 | Issue 4 | Vol 12 | Page 6
Pleural effusion sediment is commonly used to detect oncogenic mutations in lung carcinoma, but its sensitivity is limited at around 70 per cent. Cell-free DNA (cfDNA) from pleural effusion supernatant offers a potential alternative.
A feasibility study presented at the 2025 Congress evaluated the adequacy of cfDNA from pleural effusion supernatant, frozen at -80°C in a biobank, for detecting EGFR and KRAS mutations in lung adenocarcinoma.
The study analysed pleural biopsy specimens and corresponding effusion supernatants from 32 patients with lung adenocarcinoma treated at University Clinic Golnik in Slovenia between 2010 and 2020. Samples were stored in a biobank at -80°C. Targeted PCR was used to detect EGFR and KRAS mutations.
Tissue biopsy confirmed seven KRAS and four EGFR mutations. Of the seven KRAS mutations, six were in codon 12/13, and one was KRAS G12C.
Among the four EGFR mutations, two involved exon 19 deletion, one involved L858R, and one patient had both L858R and T790M mutations. cfDNA testing detected six out of seven (85.7 per cent) KRAS and all (100 per cent) EGFR mutations, showing high concordance with tissue biopsy.
The study authors concluded that cfDNA from pleural effusion supernatant is a highly accurate, non-invasive alternative for oncogenic mutation detection, even after extended biobank storage. Its diagnostic yield approaches that of histology.
The authors acknowledged that further validation is needed, but said the study demonstrates that genetic testing is feasible on older biobank samples, which could be useful for discovering new biomarkers.
Reference
Nemanic T, et al. Adequacy of cell-free DNA from pleural effusion supernatant for oncogenic mutations detection. Abstract OA5520. European Respiratory Society Congress 27 September-1 October 2025. Amsterdam, Netherlands.
