Table 5

Association between exposure categories and progesterone receptor expression

Explanatory Variable
Controls
Cases with tumors expressing PR* in 0 to 25% of cells
Cases with tumors expressing PR* in = order 25 to 100% of cells


n
n
OR (95% CI)
n
OR (95% CI)

OC* use
Never
103
15
Referent
33
Referent
Ever
183
31
3.2 (1.3 – 8.0)
64
1.1 (0.6 – 1.9)
HRT* use in post-menopausal women
Never
58
15
Referent
23
Referent
Ever
114
22
0.8 (0.4 – 1.6)
41
0.9 (0.5 – 1.6)
Current menstrual status
Menstruating
114
9
Referent
33
Referent
Post-menopausal
172
37
2.7 (1.2 – 5.8)
64
1.3 (0.8 – 2.1)
Menstrual status 10 years before reference date
Menstruating
158
21
Referent
62
Referent
Post-menopausal
126
23
0.5 (0.2 – 1.5)
35
0.5 (0.2 – 1.0)
Current menstrual status
Menstruating
72
4
Referent
17
Referent
Post-menopausal and not using HRT
58
15
2.4 (1.2 – 5.8)
23
3.1 (1.1 – 8.6)
Menstrual status 10 years before reference date
Menstruating
83
8
Referent
27
Referent
Post-menopausal and not using HRT
46
10
0.3 (0.1 – 2.5)
13
0.8 (0.5 – 1.3)
Smoking status 10 years before reference date
Non-smoker
144
29
Referent
48
Referent
Smoker
142
17
0.5 (0.3 – 1.0)
49
1.0 (0.6 – 1.5)
Body Mass Index on reference date
< 25
156
23
Referent
45
Referent
25 – 30
66
12
1.2 (0.5 – 2.5)
22
1.1 (0.5 – 2.4)
≥ 30
64
11
1.1 (0.6 – 2.0)
29
1.5 (0.8 – 2.6)
Number of live births
None
58
2
Referent
16
Referent
1
28
5
4.0 (0.7 – 22.3)
17
2.1 (0.9 – 4.9)
≥ 2
200
39
4.3 (1.0 – 18.8)
64
1.1 (0.6 – 2.2)

*PR, progesterone receptor; OC, oral contraceptive; HRT, hormone replacement therapy

† Odds ratio (OR) and 95% confidence intervals (CI) estimated from multivariable polytomous logistic regression including continuous age and three categories of education (high school or less, some college or trade school, and college graduate or graduate school) as confounding variables. None of the tests for linear trend was significant.

Custer et al. BMC Cancer 2006 6:152   doi:10.1186/1471-2407-6-152