Table 3.

Multivariate analysis of prognosis of OS | DFS and DFS | DFS at 1-yearand 2-year landmarks

		Multivariate analysis at 1-year landmark						Multivariate analysis at 2-year landmark
		OS | DFS			DFS | DFS			OS | DFS			DFS | DFS
Variable		HR	95% CI	P	HR	95% CI	P	HR	95% CI	P	HR	95% CI	P
Age, years (continuous)		1.04	1.02–1.07	<0.01	1.03	1.00–1.05	0.03	1.05	1.01–1.10	0.01
Ever-smoking
No					Ref	—	—				Ref	—	—
Yes					0.49	0.28–0.88	0.02				0.35	0.12–1.02	0.05
Histology
Squamous		Ref	—	—	Ref	—	—				Ref	—	—
Non-squamous					1.77	1.10–2.85	0.02				3.38	1.17–9.77	0.02
N status
N0–1		Ref	—	—	Ref	—	—	Ref	—	—
N2					1.58	0.68–3.66	0.29
N3					2.71	1.11–6.61	0.03
Concurrent chemoradiation
None		Ref	—	—				Ref	—	—
Platinum-Etoposide		0.39	0.19–0.83	0.01				0.27	0.80–0.89	0.03
Platinum-Taxol		0.62	0.34–1.12	0.11				0.30	0.11–0.86	0.02
Other		0.67	0.31–1.47	0.32				0.71	0.21–2.35	0.57

Abbreviations: OS | DFS, probability of surviving an additional y years for patients with disease-free survival x years; DFS | DFS, probability of surviving disease-free an additional y years for patients who have been alive and disease-free for x years; HR, hazard ratio; CI, confidence interval.