Table 6. Cox proportional hazards regression model in late-stage NSCLC patients based on the Survival tree analysis.

Risk Group	Dead (N%)	Alive (N%)	HR* (95%CI)	P-value	MST#	Log-rank P value
Chemotherapy
Low (Node 1)	70 (72.16)	27 (27.84)	Reference		13.59
Medium (Nodes 2, 4)	183 (86.73)	28 (13.27)	1.55 (1.16–2.09)	0.003	10.53
High (Node3)	42 (89.36)	5 (10.64)	2.94 (1.93–4.47)	<0.001	7.17	<0.0001
Chemoradiation
Low (Node 5)	82 (74.55)	28 (25.45)	Reference		19.28
High (Node 6)	22 (84.62)	4 (15.38)	1.89 (1.06–3.38)	0.031	12.37	0.0055

*HR adjusted by age, gender, ethnicity, smoking status and pack-years, performance status, clinical stage.

#MST, median survival time (months)