Table 1

Characteristics of breast cancer cases and controls.

Characteristic a
Cases (N = 323)
Controls (N = 649)

Age (yrs)


     <50
21%
22 %
     50–65
55
56
     >65
24
22
     Mean (SEM)
54.2 (0.7)
53.3 (0.4)
Race


     Caucasian
91 %
89 %
     All Other
9
11
Education


     < 12 yrs
12 %
12 %
     12 yrs
53
55
     > 12 yrs
31
33
Parity


     Nulliparous
6 %
4 %
     First Pregnancy <30 yrs
83
89
     First Pregnancy >30 yrs
11
7 (p < 0.05)
Family History


     Positive
29 %
16 %
     Negative
71
84 (p < 0.01)
Body Mass


     BMI < 22
23 %
21 %
     BMI 22–28
35
39
     BMI > 28
42
40
     Mean (SEM)
27.5 (0.9)
27.1 (0.7)
Menopausal Status


     Premenopausal
41 %
47 %
     Postmenopausal
59
53 (p < 0.05)
     Postmenopausal ERT
38
31 (p < 0.05)
Smoking


     Never smoker
45 %
40 %
     Ex-smoker
38
40
     Current smoker
27
20 (p < 0.02)
Alcohol Intake


     None
47 %
45 %
     1–2 drinks per week
36
35
     > 2 drinks per week
17
20

a Family History: either breast or ovarian cancer among first or second degree female relatives; ERT = Estrogen Replacement Therapy for two or more years; Body Mass Index = weight (kg)/ht2(m).

Harris et al. BMC Cancer 2006 6:27   doi:10.1186/1471-2407-6-27