Clinical characteristics of subjects
| Confirmed NSCLC | Total control group | Suspected, proven negative | Healthy volunteer | p-value | |
| Subjects n | 138 | 143 | 59 | 84 | |
| Age years | 67.1±9.1 | 62.1±7.0 | 65.2±8.8 | 59.8±4.3 | <0.001¶ |
| Males | 80 (58.0%) | 58 (40.6%) | 31 (52.5%) | 27 (32.1%) | <0.001+ |
| Smoking status | |||||
| Current smokers | 49 (35.5%) | 19 (13.3%) | 13 (22.0%) | 6 (7.1%) | <0.001+ |
| Ex-smokers | 82 (59.4%) | 76 (53.1%) | 32 (54.2%) | 44 (52.4%) | |
| Never-smokers | 7 (5.1%) | 48 (33.6%) | 14 (23.7%) | 34 (40.5%) | |
| Smoking exposure pack-years | |||||
| 0 | 7 (5.1%) | 48 (33.6%) | 14 (23.7%) | 34 (40.5%) | |
| 1–20 | 30 (21.7%) | 53 (37.1%) | 18 (30.5%) | 35 (41.7%) | <0.001+ |
| 21–40 | 53 (38.4%) | 25 (17.5%) | 17 (28.8%) | 8 (9.5%) | |
| >40 | 48 (34.8%) | 17 (11.9%) | 10 (16.9%) | 7 (8.3%) | |
| COPD | 66 (47.8%) | 22 (15.4%) | 21 (35.6%) | 1 (1.2%) | <0.001+ |
| BMI kg·m−2 | 25.6±4.6 | 25.9±4.8 | 26.9±5.9 | 25.2±3.8 | 0.104 |
| Type of NSCLC | |||||
| Adenocarcinoma | 88 (63.8%) | ||||
| Squamous cell carcinoma | 41 (29.7%) | ||||
| Large cell carcinoma | 4 (2.9%) | ||||
| NOS | 5 (3.6%) | ||||
| NSCLC stage# | |||||
| I | 25 (14.5%) | ||||
| II | 15 (10.8%) | ||||
| III | 39 (28.3%) | ||||
| IV | 64 (46.4%) |
Data are presented as mean±sd or n (%), unless otherwise stated. NSCLC: non-small cell lung cancer; BMI: body mass index; NOS: not otherwise specified.#: according to the seventh edition of the American Joint Committee on Cancer TNM staging system; ¶: after Games–Howell correction, there was a significant difference between healthy volunteers and confirmed NSCLC and healthy volunteers and suspected, proven negative subjects; +: after Holm–Bonferroni correction, there was a significant difference between healthy volunteers and confirmed NSCLC and suspected proven negative subjects.