| Controls | COPD | Adenocarcinoma | Adenocarcinoma and COPD | |
| Subjects n | 16 | 23 | 27 | 21 |
| Sex | ||||
| Male | 15 (93.8) | 20 (87.0) | 23 (85.2) | 17 (81.0) |
| Female | 1 (6.3) | 3 (13.0) | 4 (14.8) | 3 (14.3) |
| Age years | 54.1 (48.2–58.0) | 66.0 (61.0–71.0) | 59.0 (56.0–68.0) | 59.0 (54.0–69.5) |
| Smoking status | ||||
| Smokers | 15 (93.8) | 12 (52.2) | 18 (66.7) | 13 (61.9) |
| Ex-smokers | 1 (6.3) | 11 (47.8) | 9 (33.3) | 8 (38.1) |
| Smoking exposure pack-years | 40.0 (30.0–56.2) | 54.0 (40.0–75.0) | 60.0 (37.5–75.0) | 54.5 (40.0–67.5) |
| COPD | ||||
| Mild | 9 (39.1) | 5 (23.8) | ||
| Moderate | 9 (39.1) | 9 (42.8) | ||
| Severe | 4 (17.4) | 6 (28.6) | ||
| Very severe | 1 (4.3) | 1 (4.8) | ||
| Lung adenocarcinoma | ||||
| Stage I–II | 2 (9.5) | |||
| Stage III | 10 (37.0) | 5 (23.8) | ||
| Stage IV | 17 (63.0) | 14 (66.7) |
Data are presented as n (%) or median (interquartile range), unless otherwise stated. Chronic obstructive pulmonary disease (COPD) severity was categorised according to the Global Initiative for Chronic Obstructive Lung Disease stages.