Table 5. Cox proportional hazards model for the entire cohort and for the subset of patients with large tumors.

Variable	Entire cohort				Patients with tumors size ≥8 cm
	Hazard radio	95% CI	P		Hazard radio	95% CI	P
Age (per decade)	1.68	1.49–1.90	<0.001		1.56	1.31–1.86	<0.001
Female	1.10	0.82–1.48	0.50		1.26	0.81–1.95	0.30
Charlson comorbidity index (reference: 0)
1	1.44	1.03–2.02	0.03		1.09	0.62–1.92	0.80
≥2	1.46	0.78–2.75	0.20		1.79	0.70–4.57	0.20
Masaoka stage (reference: stage I–IIa)
IIb	1.06	0.72–1.58	0.80		0.85	0.43–1.68	0.60
III	1.93	1.36–2.75	<0.001		1.76	1.04–2.99	0.04
Any induction therapy	1.32	0.82–2.12	0.25		1.54	0.91–2.64	0.10
Positive margin	1.09	0.79–1.50	0.60		1.24	0.78–1.98	0.40
Tumor size ≥8 cm	1.47	1.09–1.98	0.01		n/a	n/a	n/a