Table 6. Univariate and multivariate analyses of disease-free survival.

Variable	Category	Univariate analysis			Multivariate analysis
		Hazard ratio	95% CI	p value	Hazard ratio	95% CI	p value
Whole group
T stage	T1 vs. T2-4	1.750	0.826–3.706	0.144	1.219	0.561–2.653	0.617
N stage	N0 vs. N1-3	2.468	1.147–5.311	0.021	2.715	1.254–5.875	0.011
Histologic grade	I vs. II & III	5.099	0.694–37.488	0.109	4.247	0.570–31.626	0.158
LVI	Absent vs. Present	2.735	1.245–6.008	0.012	1.984	0.840–4.687	0.118
Oct4	Negative vs. Positive	2.522	1.148–5.542	0.021	2.542	1.144–5.647	0.022
Hormone receptor-positive group
T stage	T1 vs. T2-4	2.546	1.027–6.309	0.044	2.067	0.827–5.168	0.120
N stage	N0 vs. N1-3	3.606	1.320–9.852	0.012	4.443	1.613–12.236	0.004
Histologic grade	I vs. II & III	5.533	0.742–41.246	0.095	2.789	0.352–22.089	0.331
LVI	Absent vs. Present	2.167	0.874–5.374	0.095	1.053	0.398–2.786	0.918
Oct4	Negative vs. Positive	6.346	2.662–15.128	<0.001	7.782	3.226–18.772	< 0.001
Hormone receptor-positive group treated with tamoxifen
T stage	T1 vs. T2-4	2.029	0.772–5.334	0.151	1.755	0.658–4.678	0.261
N stage	N0 vs. N1-3	2.847	1.003–8.083	0.049	3.729	1.291–10.769	0.015
Histologic grade	I vs. II & III	3.246	0.430–24.504	0.254	1.434	0.175–11.720	0.737
LVI	Absent vs. Present	1.443	0.549–3.792	0.457	0.912	0.336–2.477	0.857
Oct4	Negative vs. Positive	5.662	2.179–14.716	<0.001	7.115	2.683–18.870	< 0.001

P values were calculated by Cox proportional hazards regression model with a backward stepwise selection method.

CI, confidence interval; LVI, lymphovascular invasion.