Table 3. Univariate analysis of factors associated with disease-free survival.

Variable		Hazard ratio	95% CI	P value
Age (years)	<50	1.000
	≥50	0.987	0.471–2.071	0.973
Histologic grade	I & II	1.000
	III	1.760	0.796–3.890	0.162
pT stage	pT1	1.000
	pT2-4	5.651	2.401–13.301	<0.001
pN stage	pN0	1.000
	pN1-3	5.718	2.317–14.111	<0.001
Tumor multiplicity	Single	1.000
	Multiple	0.567	0.197–1.635	0.294
Lymphovascular invasion	Absent	1.000
	Present	3.158	1.457–6.845	0.004
P53 overexpression	Absent	1.000
	Present	1.122	0.339–3.716	0.851
Estrogen receptor	≥90%	1.000
	<90%	2.185	1.036–4.611	0.040
Progesterone receptor	≥40%	1.000
	<40%	2.756	1.303–5.828	0.008
Ki-67 index by average method	<18%	1.000
	≥18%	3.301	1.491–7.309	0.003
Ki-67 index by hot spot method	<22%	1.000
	≥22%	4.046	1.717–9.537	0.001
Chemotherapy	Not received	1.000
	Received	1.466	0.622–3.456	0.382
Radiotherapy	Not received	1.000
	Received	0.851	0.393–1.844	0.682

Abbreviation: CI, confidence interval