Factors associated with the successful obtainment of NGS from FFPE specimens
| Total specimens | Success for NGS analysis | Failure for NGS analysis | p-value | |
| Specimens, n | 106 | 73 | 33 | |
| Timepoint of taking tissues | 0.470 | |||
| Pre-treatment specimen | 44 (41.5) | 32 (43.8) | 12 (36.4) | |
| Post-treatment specimen | 62 (58.5) | 41 (56.2) | 21 (63.6) | |
| Biopsy sites | 0.274 | |||
| Lung | 52 (49.1) | 37 (50.7) | 15 (45.5) | |
| Pleura | 10 (9.4) | 6 (8.2) | 4 (12.1) | |
| Mediastinal lymph node | 8 (7.5) | 4 (5.5) | 4 (12.1) | |
| Neck lymph node | 5 (4.7) | 4 (5.5) | 1 (3.0) | |
| Brain | 8 (7.5) | 6 (8.2) | 2 (6.1) | |
| Soft tissue | 7 (6.6) | 6 (8.2) | 1 (3.0) | |
| Liver | 6 (5.7) | 4 (5.5) | 2 (6.1) | |
| Bone | 5 (4.7) | 1 (1.4) | 4 (12.1) | |
| Pleural effusion (cell block) | 4 (3.8) | 4 (5.5) | 0 | |
| Adrenal gland | 1 (0.9) | 1 (1.4) | 0 | |
| Modality for taking tissues | 0.031* | |||
| Surgery (VATS or excisional biopsy) | 51 (48.1) | 39 (53.4) | 12 (36.4) | |
| CT-guided biopsy | 21 (19.8) | 15 (20.5) | 6 (18.2) | |
| Echo-guided biopsy | 18 (17.0) | 13 (17.8) | 5 (15.2) | |
| Bronchoscopy (including EBUS-TBNA) | 16 (15.1) | 6 (8.2) | 10 (30.3) | |
| Tissue preservation time | 0.845 | |||
| ≤2 years | 40 (37.7) | 28 (38.4) | 12 (36.4) | |
| >2 years | 66 (62.3) | 45 (61.6) | 21 (63.6) |
Data presented as n (%), unless otherwise indicated. NGS: next-generation sequencing; FFPE: formalin-fixed paraffin-embedded; VATS: video-assisted thoracic surgery; CT: computed tomography; EBUS-TBNA: endobronchial ultrasound-guided transbronchial needle aspiration. *: p<0.05.