The application value of serous cavity effusion supernatant in multi-driver gene detection for non-small cell lung cancer.

Obtaining tissue from advanced non-small cell lung cancer(NSCLC) patients is difficult, yet mutation testing is crucial for targeted therapy. This study evaluates the clinical utility of serous cavity effusion (SCE) supernatant for multi-gene mutation testing, comparing its performance with cell blocks as a promising liquid biopsy alternative. SCE samples were collected from untreated NSCLC patients. Following the routine cytology and DNA ploidy analysis of the SCE samples, matching supernatant and cell block specimens were prepared and subsequently subjected to multi-gene mutation testing using Amplification Refractory Mutation System PCR (ARMS-PCR). The panel comprised 11 genes covering major variant types across EGFR, ALK, ROS1, BRAF, KRAS, NTRK1/2/3, MET, RET, and HER2. Among the 124 patients who met the inclusion criteria, the overall driver gene mutation rate was 77.42%. Mutation status correlated with DNA aneuploidy, specifically with the average DNA Index (DI) value for the top 20 cells with DI > 2.5 (P = 0.004) and the number of cells with DI > 4.5 (P = 0.022). The detection rate of the supernatant (76.61%) was higher than that of the cell blocks (73.39%), though the difference was not statistically significant (P > 0.05). In samples with a tumor cell proportion < 10%, the supernatant achieved a significantly higher detection rate than cell blocks (53.33% vs. 26.67%). The turnaround time for supernatant testing was also much shorter than that for cell blocks (4.5 h vs. 19.5 h). SCE supernatant is a highly effective, rapid, and valuable complementary specimen for multi-gene driver mutation testing in NSCLC, demonstrating superior clinical sensitivity particularly in low-tumor-content or cytologically negative specimens.