Table 3. Uni- and multivariate analysis of the training group for CSS.

Variable	Univariate analysis				Multivariate analysis
	HR	95% CI	P		HR	95% CI	P
Age (year)			0.000				0.000
<40	Reference				Reference
40-59	0.962	0.501–1.846	0.907		1.945	0.969–3.905	0.061
60-79	1.328	0.702–2.514	0.383		2.862	1.439–5.689	0.003
≥80	3.127	1.548–6.315	0.001		5.206	2.428–11.160	0.000
Sex			0.943
Male	Reference
Female	0.991	0.764–1.285	0.943
Laterality			0.597
Left	Reference
Right	0.942	0.753–1.177	0.597
Race			0.018				0.199
White	Reference				Reference
Black	0.793	0.609–1.031	0.083		0.783	0.595–1.031	0.081
Other	1.601	1.002–2.560	0.049		0.845	0.519–1.376	0.498
T stage			0.000				0.000
T1	Reference				Reference
T2	3.575	2.580–4.954	0.000		2.326	1.652–3.275	0.000
T3–T4	10.258	8.000–13.154	0.000		3.536	2.617–4.778	0.000
N stage			0.000				0.001
N0	Reference				Reference
N1	18.858	14.836–23.971	0.000		1.855	1.304–2.638	0.001
M stage			0.000				0.000
M0	Reference				Reference
M1	32.313	25.445–41.035	0.000		6.952	4.758–10.156	0.000
Surgery			0.000				0.000
No	Reference				Reference
Yes	0.121	0.090–0.162	0.000		0.345	0.237–0.501	0.000
LNR			0.000				0.000
No	Reference				Reference
Yes	5.682	4.462–7.234	0.000		2.111	1.540–2.894	0.000
Radiation			0.000				0.658
No	Reference				Reference
Yes	17.441	12.216–24.901	0.000		0.911	0.603–1.377	0.658
Chemotherapy			0.000				0.043
No/unknown	Reference				Reference
Yes	23.700	18.392–30.541	0.000		1.447	1.011–2.072	0.043
Marital status			0.012				0.629
Married	Reference				Reference
Previously married	1.444	1.104–1.890	0.007		1.148	0.866–1.522	0.336
Never married	0.918	0.673–1.252	0.918		1.051	0.756–1.462	0.766
Insurance status			0.080
Any medicaid	Reference
Insured	0.720	0.521–0.994	0.046
Uninsured	0.492	0.210–1.157	0.104

CSS, cancer-specific survival; HR, hazard ratio; CI, confidence interval; LNR, lymph node removal.