Table 2.

Univariate Cox proportional hazards model for survival until death from breast cancer at 3 years and 10 years.

		3 years		10 years
Variable	Definition	RR (95% CI)	P	RR (95% CI)	P
Center	VGH	1.		1.
	JGH	0.67 [0.35; 1.31]	.25	0.76 [0.51; 1.13]	.17
Age of diagnosis	< 50 years	1.		1.
	≥ 50 years	1.10 [0.55; 2.16]	.79	0.97 [0.66; 1.44]	.89
Histological grade*, §	1	1.		1.
	2	2.62 [0.88; 7.80]	.08	1.63 [0.97; 2.73]	.06
	3	5.47 [1.84; 16.2]	.002	2.37 [1.36; 4.11]	.002
Tumor Size§	< 2 cm	1.		1.
	≥ 2 cm	3.22 [1.42; 7.32]	.005	2.82 [1.78; 4.46]	.0001
Lymph nodes§	No	1.		1.
	Yes	2.78 [1.37; 5.65]	.005	2.21 [1.46; 3.32]	.0002

* Test of overall histological grade. P-value = 0.004 (at 3 years) and 0.009 (at 10 years).

^§ Adjusting for missing values.

The total number of subjects is 456. The total number of events is 39 at 3 years and 111 at 10 years.