Table 2.
Risk factors for interstitial pneumonia
| Risk factor | Case group (n = 11) n (%) | Control group (n = 22) n (%) | p value |
|---|---|---|---|
| Smoking history | |||
| Current and past | 11 (100) | 19 (86.4) | 0.54 |
| Never | 0 | 3 (13.6) | |
| Histology(except NOS) | |||
| Adenocarcinoma | 7 (63.6) | 17 (81.0) | 0.40 |
| Squamous cell carcinoma | 4 (36.4) | 4 (19.0) | |
| PD-L1 expression [TPS (%)] (except unknown) | |||
| <1% | 0 | 4 (30.8) | 0.28 |
| ≥1% | 5 (100) | 9 (69.2) | |
| Stage | |||
| III | 4 (36.4) | 3 (13.6) | 0.19 |
| IV | 7 (63.6) | 19 (86.4) | |
| History of lung surgery | |||
| Yes | 3 (27.3) | 4 (18.2) | 0.66 |
| No | 8 (72.7) | 18 (81.8) | |
| History of radiation therapy | |||
| Yes | 6 (54.5) | 8 (36.4) | 0.46 |
| No | 5 (45.5) | 14 (63.6) | |
| History of illness: pulmonary emphysema and COPD | |||
| Yes | 1 (9.1) | 2 (9.1) | 1.00 |
| No | 10 (90.9) | 20 (90.9) | |
| Treatment line | |||
| 1 | 2 (18.2) | 6 (27.3) | 0.69 |
| ≥2 | 9 (81.8) | 16 (72.7) | |
| History of interstitial pneumonia | |||
| NSCLC treatment-related interstitial pneumoniaa | 9 (81.8) | 9 (40.9) | 0.03 |
| Idiopathic interstitial pneumoniab | 2 (18.2) | 13 (59.1) | |
NOS not otherwise specified; PD-L1 programmed death-ligand 1; TPS tumor proportion score; COPD chronic obstructive pulmonary disease; NSCLC non-small-cell lung cancer
aICI-induced interstitial pneumonia and radiation pneumonitis
bIdiopathic interstitial pneumonia is an interstitial pneumonia of unknown cause