Table 2. Cox regression analysis of nuclear APE1 expression on OS in invasive breast cancer defined by the Ki-67 low-level expression cohort.

Characteristic		OS (n = 151)
		n	HR	95% CI	p-value
Age (years)				0.174–2.516	0.543
	<50	72	1
	≥50	65	0.661
T stage				0.824–21.996	0.084
	T1-T2	130	1
	T3-T4	7	4.258
Lymph node metastasis				0.196–2.876	0.675
	Negative	92	1
	Positive	45	0.750
Estrogen receptor				0.262–25.453	0.416
	Negative	20	1
	Positive	117	2.584
HER2				0.314–5.272	0.726
	Negative	105	1
	Positive	32	1.286
Histologic grade				0.302–9.010	0.564
	I+II	122	1
	III	15	1.649
APE1 expression				0.039–0.962	0.045
	Low	32	1
	High	105	0.193