P79 The utility of endobronchial cryobiopsy in the molecular diagnosis of lung cancer

Introduction and objectives Forceps biopsy is the standard bronchoscopic approach for endobronchial lesions, with a diagnostic yield of 76%.1 Endobronchial cryobiopsy produces larger specimens with less crush artifact and increases diagnostic yield.2 We assessed the utility of cryobiopsy in the initial diagnosis of lung cancer and determined its yield for molecular testing. Method Prospective review of endobronchial cryobiopsies at a tertiary centre between August 2017-June 2018. Suspected lung cancer cases with a visible endobronchial component on CT thorax were streamed to cryobiopsy. Cryobiopsy via flexible bronchoscopy was performed using 1.9 mm cryoprobe and ERBOKRYO system under conscious sedation with midazolam and fentanyl. Mean dose of midazolam was 2.6 mg and Fentanyl 66.3 microgram. Data was collected on baseline patient demograph, number of biopsies, complications, final histology and molecular markers. Results 28 cryobiopsies were performed for suspected lung cancer. Mean age 69.1 years, 54% (15/28) male with mean 2.4 cryobiopsy specimens. Overall diagnostic yield was 89.2% (25/28). Non-small cell lung cancer (NSCLC)=60.7% (17/28) of which adenocarcinoma 17.6% (3/17), squamous cell carcinoma 58.8% (10/17) and 23.5% (4/17) NSCLC not otherwise specified. Small cell lung carcinoma (SCLC)=17.8% (5/28), mucoepidermoid carcinoma=7% (2/28) and chronic inflammation=3.6% (1/28). Of the 3 non-diagnostic cryobiopsies; 1 underwent CT-guided lung biopsy and was NSCLC (squamous) and 2 were known NSCLC referred for molecular testing where tissue was inconclusive and did not alter management. In 17 NSCLC patients, cryobiopsy was sufficient in providing tissue for molecular testing in 88% (15/17). Complications; 64.2% (18/28) mild bleeding and 35.7% (10/28) had moderate bleeding with haemostasis achieved using cold saline and adrenaline. Conclusion This is the first study that demonstrates the dual utility of first-line cryobiopsy in the diagnosis and molecular testing of lung cancer. References https://www.brit-thoracic.org.uk/document-library/audit-and-quality-improvement/audit-reports/bts-adult-bronchoscopy-audit-report-2017/ Hetzel J, Eberhardt R, Herth FJF, et al. Cryobiopsy increases the diagnostic yield of endobronchial biopsy: A multicentre trial. Eur. Respir. J 2012;39:685–90.