Table 3.

Demographic and clinical characteristics of patients with lung cancer in the survival discovery and validation sets

Discovery set (N = 330)Validation set (N = 331)
VariablesLung cancer patients, n (%)Deaths (n = 257)Lung cancer patients, n (%)Deaths (n = 242)MST,a moLog-rankaPHR (95% CI)a, b
Age, y
 ≤65172 (52.1)127228 (68.9)16317.9<0.0011.00 (Reference)
 >65158 (47.9)130103 (31.1)7913.41.39 (1.16–1.66)
Sex
 Male274 (83.0)213247 (74.6)17915.30.2221.00 (Reference)
 Female56 (17.0)4484 (25.4)6319.90.88 (0.71–1.08)
Smoking
 Never66 (20.0)51122 (36.9)9319.50.0731.00 (Reference)
 Former smokers160 (48.5)12532 (9.7)2414.21.29 (1.03–1.63)
 Current smokers104 (31.5)81177 (53.5)12516.51.07 (0.86–1.32)
Histology
 Adenocarcinoma140 (42.4)106212 (64.0)15418.4<0.0011.00 (Reference)
 SCC93 (28.2)7098 (29.6)7216.50.94 (0.76–1.15)
 Othersc97 (29.4)8121 (6.3)1611.21.55 (1.23–1.96)
Stage
 IIIA76 (23.0)49140 (42.3)10119.6<0.0011.00 (Reference)
 IIIB85 (25.8)6472 (21.8)4618.01.14 (0.89–1.46)
 IV169 (51.2)144119 (36.0)9512.71.83 (1.49–2.25)
Surgery
 No241 (73.0)188179 (54.1)14313.4<0.0011.00 (Reference)
 Yes89 (27.0)69152 (45.9)9921.00.58 (0.48–0.70)
Chemotherapy
 No75 (22.7)5831 (9.4)2610.0<0.0011.00 (Reference)
 Yes255 (77.3)199300 (90.6)21617.80.63 (0.50–0.80)
Radiotherapy
 No178 (53.9)135208 (62.8)15314.20.0531.00 (Reference)
 Yes152 (46.1)122123 (37.2)8918.60.84 (0.70–1.00)

Abbreviations: HR, hazard ratio; SCC, squamous cell carcinoma.

  • aData are for the combined discovery and validation sets.

  • bData were calculated by univariate Cox regression analysis.

  • cOthers include large cell, bronchioalveolar, mixed cell, undifferentiated and pathologic not otherwise specified carcinomas.