Table 2 Uni- and multivariable Cox regression analyses for DFS in the discovery cohort and validation cohort
Variables | Discovery cohort | Validation cohort | |||||||
|---|---|---|---|---|---|---|---|---|---|
Univariable analysis | Multivariable analysisa | Univariable analysis | Multivariable analysisa | ||||||
Unadjusted HRb (95% CI) | P | Adjusted HRc (95% CI) | P | Unadjusted HRb (95% CI) | P | Adjusted HRc (95% CI) | P | ||
Age at surgery (years) | |||||||||
≥ 65 vs. < 65 | 1.13 (0.70–1.82) | 0.624 | 1.00 (0.58–1.73) | 0.991 | |||||
Sex | |||||||||
Female vs. male | 0.63 (0.39–1.03) | 0.067 | 0.58 (0.36–0.94) | 0.026 | |||||
Smoking status | |||||||||
Former/current vs. never | 1.08 (0.66–1.78) | 0.748 | 1.18 (0.76–1.84) | 0.469 | |||||
TNM stage | |||||||||
Stage II vs. stage I | 3.82 (1.99–7.34) | < 0.001 | 2.41 (1.13–5.18) | 0.024 | 2.95 (1.68–5.18) | < 0.001 | 2.87 (1.64–5.06) | < 0.001 | |
Stage III vs. stage I | 5.69 (3.33–9.73) | < 0.001 | 2.84 (1.33–6.06) | 0.007 | 3.62 (2.15–6.09) | < 0.001 | 3.23 (1.91–5.48) | < 0.001 | |
Differentiation grade | |||||||||
G3/G4 vs. G1/G2 | 2.79 (1.72–4.52) | < 0.001 | 1.68 (1.01–2.82) | 0.047 | 1.56 (1.00–2.43) | 0.050 | |||
Surgical resection | |||||||||
Limited resection vs. lobectomy/pneumonectomy | 1.37 (0.63–2.99) | 0.429 | 1.56 (0.49–4.94) | 0.451 | |||||
Adjuvant chemotherapy | |||||||||
Yes vs. no | 3.83 (2.38–6.15) | < 0.001 | 1.77 (0.91–3.41) | 0.090 | 2.23 (1.35–3.68) | 0.002 | |||
I-score (three-category) | |||||||||
Intermediate vs. low | 0.79 (0.42–1.46) | 0.447 | 1.05 (0.57–1.96) | 0.867 | |||||
High vs. low | 0.44 (0.25–0.78) | 0.005 | 0.49 (0.26–0.93) | 0.029 | |||||
I-score (two-category) | |||||||||
High vs. low | 0.51 (0.32–0.81) | 0.004 | 0.57 (0.36–0.92) | 0.022 | 0.47 (0.30–0.75) | 0.001 | 0.54 (0.33–0.86) | 0.010 | |