Table 7.

Multivariable Cox regression (SOD₂ TC/TT or CAT CC, n = 260).

Feature		HR	CI (2.5–97.5%)	p-Value
Serum zinc level	A	2.497	1.48–4.21	<0.01
	B	1.318	0.76–2.28	0.324
	C	1.0
Sex	F	1.0
	M	0.72	0.42–1.24	0.238
Clinical stage	I	1.0
	II	2.379	0.9–6.29	0.08
	III	2.207	0.93–5.25	0.073
	IV	5.916	2.54–13.77	<0.01
Chemotherapy	Yes	0.792	0.41–1.53	0.488
	No	1.0
Radiotherapy	Yes	1.628	0.96–2.76	0.071
	No	1.0
Pack-years		1.009	1–1.02	0.147
Age	≤60	1.0
	>60	1.205	0.79–1.84	0.39