Table 1 Patient characteristics
Variable | Study population | Variable | Study population |
|---|---|---|---|
(n = 469) |  | (n = 469) | |
Age (years) | 64.1 ± 11.4 | N stage |  |
Gender | Â | N0 | 117 (24.9) |
 Male | 235 (50.1) | N1 | 65 (13.9) |
 Female | 234 (49.9) | N2 | 134 (28.6) |
Smoking status | Â | N3 | 153 (32.6) |
 Never smokers | 115 (24.5) | Extrathoracic metastasis/−es | 213 (45.4) |
 Ex-smokers | 160 (34.1) | M stage |  |
 Current smokers | 194 (41.4) | M0 | 168 (35.8) |
Clinical stage | Â | M1a | 88 (18.8) |
 I | 34 (7.2) | M1b | 72 (15.4) |
 II | 36 (7.7) | M1c | 141 (30.1) |
 III | 100 (21.3) | Localization |  |
 IV | 299 (63.8) | Right upper lobe | 121 (25.8) |
T stage | Â | Right lower lobe | 65 (13.9) |
 T1 | 68 (14.5) | Middle lobe | 19 (4.1) |
  T1a | 9 (1.9) | Left upper lobe | 88 (18.8) |
  T1b | 28 (6.0) | Left lower lobe | 73 (15.6) |
  T1c | 31 (6.6) | Lingula | 14 (3.0) |
 T2 | 120 (25.6) | Involvement of two lobes | 89 (19.0) |
  T2a | 81 (17.3) | Distribution |  |
  T2b | 39 (8.3) | Central | 96 (20.5) |
 T3 | 93 (19.8) | Peripheral | 323 (68.9) |
 T4 | 188 (40.1) | Central and peripheral | 50 (10.7) |
Lymph node metastasis/−es | 352 (75.1) | Size (mm) | 45 ± 25 |