FILM-Screen: A fully integrated microfluidic platform for point-of-care lung cancer screening via multiplexed mRNA profiling in blood.

Tumor biomarkers are crucial for early cancer diagnosis. Liquid biopsy via mRNA profiling in blood offers a sensitive and non-invasive approach, but current methods are often complex, time-consuming, expensive, and ill-suited for point-of-care (POC) use. To address these limitations, we developed FILM-Screen, a Fully Integrated Liquid biopsy Microfluidic platform that automates the complete "sample-to-report" workflow. The system uniquely combines syringe-based chemical lysis and bead-based nucleic acid extraction with low-volume (1.41 μL) reverse transcription loop-mediated isothermal amplification (RT-LAMP) in a disposable 24 chambers chip, followed by on-chip, real-time multiplex fluorescence detection. This integrated design enables the simultaneous quantification of up to 22 targets with high sensitivity, achieving a detection limit of 10 copies/μL for RNA. Clinical validation was performed using a 19-mRNA biomarker panel on 65 blood samples. The platform, coupled with an XGBoost classifier, accurately discriminated healthy individuals, patients with benign pulmonary nodules, and lung cancer cases, achieving area under the curve (AUC) values of 0.993, 0.991, and 0.977, respectively. By integrating all steps from sample input to result output, FILM-Screen reduces reagent consumption by approximately 95% compared to standard tube-based methods and completes the analysis within 75 min. It thus represents a sensitive, automated, multiplexed, cost-effective, and portable system for non-invasive lung cancer screening, demonstrating strong potential for deployment in POC and resource-limited settings.