The role of radial endobronchial ultrasound for peripheral lung cancer tissue sampling and prognostic biomarkers analysis – a single-center retrospective study

Introduction: Tissue sampling of peripheral pulmonary neoplasms for patohistology and analysis of prognostic biomarkers can be challenging. Radial endobronchial ultrasound (R-EBUS) is one of the modern bronchoscopic modalities used for more precise localization of the peripheral lesions. Novel therapeutic strategies rely on different prognostic biomarkers status. Aim: to explore the sufficiency of specimens for patohistology and prognostic biomarkers analysis obtained by ultra-thin bronchoscope combined with R-EBUS. Material and Methods: Retrospective analysis of bronchoscopy cases positive on malignancies where R-EBUS was used for visualization of peripheral tumors. Samples with malignant cells found were analyzed regarding the ability to provide exact histology type and predictive biomarkers information. Results: 80 consecutive cases with pathologic ultrasound pattern were analyzed. Malignant disease was diagnosed in 49 cases (61%). Mean lesion diameter was 24mm (range 15 to 40mm). The most common histology types were adenocarcinoma, squamous cell carcinoma, and small cell carcinoma – 78%, 12%, and 4% respectively. Extrathoracic malignancies were diagnosed in 6% of cases. The tissue was sufficient for prognostic biomarker analysis in 91% of the cases – whereas EGFR, ALK, ROS1, and PDL-1 testing was performed. In 9% of cases, samples were sufficient for histologic typing only. Conclusion: bronchoscopy with R-EBUS is a useful diagnostic method for peripheral lung tumors. Obtained samples are sufficient for histology typing and prognostic biomarkers analysis in most cases as well.