Table 3.

Cox regression stratified model for survival outcomes among patients with different levels of ER staining in the primary tumor

	HRa	SE	P value	95% CI
Distant recurrence-free survival
ER staining
1%–9%	Reference
≥10%	0.7	0.06	<0.001	0.6	0.8
Negative	1.2	0.2	0.3	0.8	1.7
Recurrence-free survival
ER staining
1%–9%	Reference
≥10%	0.7	0.06	<0.001	0.6	0.8
Negative	1.2	0.2	0.2	0.9	1.7
Overall survival
ER staining
1%–9%	Reference
≥10%	0.8	0.06	0.002	0.7	0.9
Negative	1.5	0.2	0.02	1.1	2.0

^aStratified by tumor grade and clinical stage.

HR, hazard ratio; SE, standard error; CI, confidence interval.