Table 4. Risk score and patient survival for training and validation cohort.

Risk score	MST (months, 95% CI)		Log-Rank P	Hazard Ratio* (95% CI)
Training cohort			0.003
Low risk (n = 46)	9.4	7.26–10.7		1.00
High risk (n = 46)	4.0	2.59–5.41		2.50	1.40–3.85
Validation cohort			0.04
Low risk (n = 61)	9.0	6.65–11.4		1.00
High risk (n = 31)	5.8	4.68–7.32		1.62	1.11–2.84

^*Analysis was adjusted for age, gender, smoking status and histology.

Abbreviations: MST, median survival time; CI, confidence interval.