Patient characteristics
| Characteristics | Total | Malignant | Benign | P |
|---|---|---|---|---|
| Gender, n (%) | 0.803 | |||
| Male | 153 (51.2) | 104 (50.5) | 49 (52.7) | |
| Female | 146 (48.8) | 102 (49.5) | 44 (47.3) | |
| Age in years, mean (SD) | 57.7 (10.7) | 59.5 (10.2) | 53.6 (10.8) | <0.001 |
| Smoking history*, n (%) | 0.415 | |||
| Non smoker | 157 (52.5) | 112 (54.4) | 45 (48.4) | |
| Smoker | 120 (40.1) | 91 (44.2) | 29 (31.2) | |
| Pack-year smoking history*, median (IQR) | 45.0 (20.0–80.0) | 45.0 (20.0–80.0) | 22.5 (15.0–45.0) | 0.039 |
| Family cancer history*, n (%) | 0.299 | |||
| No | 225 (75.3) | 168 (81.6) | 57 (61.3) | |
| Yes | 52 (17.4) | 35 (17.0) | 17 (18.3) | |
| Clinical symptoms*, n (%) | 0.342 | |||
| No | 155 (51.8) | 110 (53.4) | 45 (48.4) | |
| Yes | 122 (40.8) | 93 (45.1) | 29 (31.2) | |
| COPD, n (%) | 0.514 | |||
| No | 247 (82.6) | 168 (81.6) | 79 (84.9) | |
| Yes | 52 (17.4) | 38 (18.4) | 14 (15.1) | |
| EGFR mutation | ||||
| EGFR 19 | 13 (20.0) | 13 (20.0) | - | |
| EGFR 21 | 15 (23.1) | 15 (23.1) | - | |
| EGFR wild type | 37 (56.9) | 37 (56.9) | - | |
*A total of 22 outpatients with no information on smoking, cancer history, family cancer history, and clinical symptoms. SD, standard deviation; IQR, interquartile range.