Table 2 Univariate and multivariate Cox analyses of the immune-related gene signature in one training set and two validation sets

Training set

 Immune-related gene signature (high- vs. low-risk)

2.57 (1.85–3.56)

1.68 (1.11–2.54)

 Age (≥ 65 vs. <65 years)

1.21 (0.88–1.66)

 Gender (male vs. female)

1.05 (0.77–1.43)

 Tumor stage (stage 3–4 vs. 1–2)

2.81 (2.03–3.88)

1.69 (1–2.86)

 T (T 3–4 vs. 1–2)

2.41 (1.61–3.60)

1.48 (0.9–2.44)

 M (positive vs. negative)

1.86 (1.06–3.25)

1.05 (0.53–2.06)

 N (positive vs. negative)

2.64 (1.93–3.62)

1.71 (1.09–2.66)

 Smoking (yes vs. no)

0.89 (0.57–1.41)

Validation set 1

 Immune-related gene signature (high- vs. low-risk)

9.11 (3.21–25.82)

8.63 (2.95–25.21)

 Age (≥ 65 vs. <65 years)

1.89 (0.96–3.71)

 Gender (male vs. female)

1.52 (0.78–2.96)

 Smoking (yes vs. no)

1.64 (0.84–3.20)

 KRAS mutation (yes vs. no)

0.87 (0.27–2.85)

 EGFR mutation (yes vs. no)

0.47 (0.24–0.93)

0.86 (0.43–1.73)

Validation set 2

 Immune-related gene signature (high- vs. low-risk)

2.80 (1.87–4.17)

2.38 (1.57–3.62)

 Age (≥ 65 vs. <65 years)

1.38 (0.89–2.14)

 Gender (male vs. female)

1.55 (1.07–2.25)

1.42 (0.97–2.09)

 Smoking (yes vs. no)

1.37 (0.60–3.14)

 Tumor stage (stage 3–4 vs. 1–2)

2.61 (1.74–3.91)

2.63 (1.74–3.97)

 KRAS mutation (yes vs. no)

1.46 (1.00–2.12)

1.1 (0.74–1.62)

 EGFR mutation (yes vs. no)

0.26 (0.10–0.71)

0.4 (0.14–1.10)

 TP53 mutation (yes vs. no)

1.24 (0.82–1.86)