A Novel Approach to Detect Programed Death Ligand 1 (PD-L1) Status and Multiple Tumor Mutations Using a Single Non–Small-Cell Lung Cancer (NSCLC) Bronchoscopy Specimen

Publication date: Available online 13 February 2019Source: The Journal of Molecular DiagnosticsAuthor(s): Amanda Vannitamby, Shona Hendry, Tanvi Makadia, Janine Danks, John Slavin, Louis Irving, Daniel Steinfort, Steven BozinovskiMultiple biomarkers are under evaluation to guide the use of immune checkpoint inhibitors in non–small-cell lung cancer (NSCLC), including programed death ligand 1 (PD-L1) tumor cell staining. We have developed a new approach that accurately quantifies PD-L1 status and identifies multiple mutations by using a single bronchoscopy specimen. A novel molecular marker was identified to detect the presence of malignant cells in radial endobronchial ultrasound bronchial brushings from NSCLC (n = 15) and benign (n = 13) nodules by quantitative real-time RT-PCR (RT-qPCR). The MMP9:TIMP3 transcript ratio was significantly increased in NSCLC and using receiver operating characteristic curve analysis accurately discriminated malignant and benign bronchoscopy specimens (area under the curve = 0.98; 95% CI, 0.93–1; P < 0.0001). Utilizing the same specimens, PD-L1 expression and multiple oncogenic mutations were detected by RT-qPCR and next-generation sequencing. A second archive of snap-frozen squamous cell carcinoma (n = 40) and control (n = 20) biopsies with matching formalin-fixed, paraffin-embedded slides were used to compare PD-L1 status by immunohistochemistry and RT-qPCR. The biopsy cohort confirmed that the MMP-9:TIMP3 ratio was predictive of m...
Source: The Journal of Molecular Diagnostics - Category: Pathology Source Type: research