Table 2 |
|||
|
Characteristics of controls in the nested case–control study according to benign breast disease category |
|||
| Category of benign breast disease |
|||
|
|
|||
| Descriptive characteristic |
Nonproliferative |
Proliferative without atypia |
Atypical hyperplasia |
|
|
|||
| Mean |
|||
| Age at biopsy (y) |
42.5 |
43.7 |
50.1 |
| Year of biopsyb |
1979 |
1980 |
1983 |
| Age at menarche (y) |
12.7 |
12.5 |
12.9 |
| Age at first birthc (y) |
24.8 |
24.9 |
25.0 |
| Age at menopaused |
46.6 |
46.5 |
47.2 |
| Body mass index, kg/m2 |
25.1 |
24.6 |
24.5 |
| Parity |
2.8 |
2.7 |
2.9 |
| Recent alcohol consumption, g/day |
4.8 |
5.4 |
6.6 |
| Frequency, % |
|||
| Premenopausal at biopsy |
76.5 |
76.1 |
57.1 |
| Family history of breast cancer |
11.2 |
13.3 |
18.3 |
| Nulliparous |
6.5 |
8.2 |
5.6 |
| Natural menopause d |
46.8 |
50.7 |
48.5 |
| Bilateral oophorectomyd |
20.1 |
16.8 |
17.5 |
|
|
|||
|
aNurses' Health Study I (1976 to 1994) and II (1989 to 1995). bMedian. cAmong parous women only. dAmong postmenopausal women. |
|||
|
Tamimi et al. Breast Cancer Research 2005 7:R555 doi:10.1186/bcr1039 |
|||
