Table 1

Characteristics of the breast cancer case – control sample in the European Prospective into Cancer-Norfolk cohort


Cases (n = 237)
Controls (n = 952)
P valuea

Age (years)
58.5 (8.6)
58.7 (8.9)
0.791
Weight (kg)
69.2 (11.4)
67.7 (11.2)
0.068
Energy intake (kcal/day)
1745.9 (386.6)
1678.6 (385.2)
0.022
Fat intake (g/day)
66.5 (19.7)
63.5 (20.1)
0.038
Alcohol intake (g/day)
8.6 (12.1)
7.8 (11.2)
0.179
Oestradiol (pmol/l)b
173.1 (341.3)
136.9 (259.4)
0.066
Age at menarche (years)
12.8 (1.6)
13.0 (1.5)
0.058
Family history of breast cancer: yes
23 (10%)
74 (8%)
0.216
Breastfed children: yes
155 (65%)
617 (65%)
0.865
Number of children



     0
38 (16%)
117 (12%)
0.174
     1
26 (11%)
134 (14%)

     2
103 (43%)
398 (42%)

     3
57 (24%)
218 (23%)

     4+
13 (6%)
85 (9%)

Menopausal statusc



     Premenopausal
28 (12%)
123 (13%)
0.569
     Perimenopausal
15 (6%)
51 (5%)

     Postmenopausal 1
57 (24%)
195 (21%)

     Postmenopausal 2
137 (58%)
583 (61%)

Menopausal hormone therapy use



     Current
63 (27%)
207 (22%)
0.256
     Former
30 (13%)
118 (12%)

     Never
144 (61%)
627 (66%)

Oral contraceptive use



     Current
9 (4%)
13 (1%)
0.041
     Former
98 (41%)
419 (44%)

     Never
130 (55%)
520 (55%)

Social class



     Professional/manager
105 (45%)
405 (42%)
0.620
     Skilled nonmanual
46 (20%)
171 (18%)

     Skilled manual
51 (22%)
197 (21%)

     Semi-skilled/nonskilled
20 (9%)
112 (12%)

     Missing/unclassified
15 (4%)
67 (7%)

Smoking status



     Current
26 (11%)
94 (10%)
0.822
     Former
70 (30%)
297 (32%)

     Never
137 (59%)
550 (59%)


Data presented as mean ± standard deviation or n (column percentage). aP values obtained with a t test for continuous values and a chi-square test for categorical variables. bOestradiol data availability: serum phytoestrogens, 153 cases and 603 controls (51 cases and 185 controls among the oestrogen receptor-positive subgroup); urinary phytoestrogens, 141 cases and 543 controls (49 cases and 171 controls among the oestrogen receptor subgroup). cPerimenopausal, <1 year since last menstrual cycle; postmenopausal 1, 2 to 5 years since last menstrual cycle; postmenopausal 2, 5 years or more since last menstrual cycle.

Ward et al. Breast Cancer Research 2008 10:R32   doi:10.1186/bcr1995