47P Next-generation sequencing using tissue specimen collected with a 1.1 mm-diameter cryoprobe in patients with lung cancer

Next-generation sequencing (NGS) analysis is considered standard for lung cancer diagnosis in clinical practice. Little is known about the feasibility of NGS using tumor tissue sampled with a 1.1 mm-diameter cryoprobe. We aimed to investigate the suitability of specimens obtained by transbronchial cryobiopsy (TBC) using a 1.1 mm-diameter cryoprobe for NGS analysis. Patients with lung cancer who underwent TBC using a 1.1 mm-diameter cryoprobe for NGS testing between October 2020 and April 2023 were enrolled. A 4.0 mm- or 3.0 mm-diameter bronchoscope with radial probe endobronchial ultrasound and virtual bronchoscopic navigation was used to detect peripheral lung lesions. All procedures were performed under fluoroscopic guidance. Data was analyzed retrospectively. A total of 56 patients underwent TBC using a 1.1-mm cryoprobe for NGS testing during the study period. Most patients (98%) were in the advanced stage of lung cancer (recurrent or inoperable disease of stages III or IV). The diagnostic yield of NGS for DNA and RNA sequencing was 95% each (53 of 56). Of the 53 patients with positive NGS results, 29 (55%) harbored actionable mutations. Details of the reported mutations are shown in the table. Moderate bleeding was found in three patients (5%), and none of the study patients developed life-threatening complications, including pneumothorax or lung infection.Table: 47PActionable mutationNo. (%)EGFR mutationCommon (19del or L858R)12 (21)Exon 20 insertion1 (2)EGFR + other5 (9)ALK fusion3 (5)ROS1 fusion1 (2)KRAS G12C2 (4)BRAF0 (0)NTRK0 (0)METExon 14 skipping1 (2)Amplification3 (5)RET fusion1 (2)ERBB1 (2) Open table in a new tab TBC using a 1.1 mm-diameter cryoprobe is a useful and safe tool for NGS analysis, for both DNA and RNA sequencing.