Table 4.

Univariate and multivariate analysis of cancer-specific survival (CSS).

	Univariate analysis		Multivariate analysis
Variable	HR (95% CI)	P value	HR (95% CI)	P value
Age
<50	reference		reference
50–64	1.135 (0.953–1.350)	.155	0.695 (0.350–1.380)	.298
≥65	1.192 (1.005–1.415)	.044∗	1.752 (0.910–3.372)	.093
Race
White	reference		reference
Black	1.775 (1.536–2.050)	<.0001∗	1.505 (0.910–2.489)	.111
Other	0.705 (0.519–0.957)	.025∗	0.599 (0.184–1.958)	.397
Histology
Ductal	reference		reference
Papillary	0.291 (0.165–0.515)	<.0001∗	–	.952
Others	0.961 (0.830–1.113)	.598	0.839 (0.426–1.653)	.612
Marital status
Single	reference		reference
Married	0.755 (0.640–0.892)	.001∗	0.502 (0.306–0.826)	.007∗
Separated/Widowed/Divorced	1.285 (1.054–1.566)	.013∗	1.100 (0.600–2.017)	.757
AJCC stage
I	reference		reference
II	2.488 (2.006–3.087)	<.0001∗	1.874 (0.939–3.743)	.075
III	6.460 (5.194–8.035)	<.0001∗	6.601 (3.228–13.500)	<.0001∗
IV	29.153 (22.859–37.181)	<.0001∗	42.960 (19.558–94.363)	<.0001∗
Grade
I	reference		reference
II	2.172 (1.603–2.942)	<.0001∗	1.303 (0.499–3.406)	.589
III	4.199 (3.110–5.668)	<.0001∗	2.583 (1.016–6.566)	.046∗
IV	6.191 (3.966–9.664)	<.0001∗	NI	NI
ER status
Positive	reference		reference
Negative	1.759 (1.361–2.273)	.058	4.734 (2.118–10.579)	<.0001∗
PR status
Positive	reference		reference
Negative	1.835 (1.552–2.169)	<.0001∗	2.402 (1.280–4.506)	.006∗
Her2 status
Positive	reference		reference
Negative	0.611 (0.390–0.958)	.032∗	0.962 (0.565–1.638)	.886
Radiation
No	reference		reference
Yes	1.446 (1.281–1.632)	<.0001∗	0.609 (0.391–0.950)	.029∗
Surgery
Refused	reference		reference
Performed	0.142 (0.098–0.206)	<.0001∗	0.833 (0.242–2.869)	.772

^∗represent the P value <.05.