Table 2.

Breast cancer risk factors by estrogen receptor status.

	Estrogen receptor positive		Estrogen receptor negative
Factor	Adjusted OR (95% CI)a	p trendb	Adjusted OR (95% CI)	p trendb
Weight (kg) by quartile
<58	1.0 ref.c		1.0
58-64	0.7 (0.5-1.5)		1.3 (0.5-3.6)
65-71	1.1 (0.7-1.8)		1.9 (0.7-4.9)
>71	1.2 (0.7-1.9)	>0.20	2.1 (0.8-5.9)	0.10
Number of full term pregnancies
0	1.0		1.0
1	1.0 (0.6-1.6)		1.7 (0.6-5.1)
>1	0.6 (0.4-0.9)	0.01	1.2 (0.5-3.1)	>0.20
Hormone replacement-therapy
Never	1.0		1.0
Ever	1.1 (0.7-1.7)		1.8 (0.8-4.1)

^a Odds ratio, 95% confidence interval, age-adjusted; ^b two sided p-value for linear trend in OR's, ^c reference category.