Table 1.
Characteristics of study population by lobule type in women with benign breast disease
| No type 1 lobules or mixed lobule types (n = 398) | Predominant type 1 and no type 3 lobules (n = 74) | |
|---|---|---|
| Age at biopsy (years) | 41.5 (4.6) | 44.2 (5.8) |
| Body mass index (kg/m2) | 25.6 (5.7) | 28.0 (8.0) |
| Parity (among parous) | 2.3 (0.8) | 2.4 (1.0) |
| Age at first birth (among parous) | 26.2 (4.1) | 26.2 (4.7) |
| Height | 64.8 (2.5) | 64.5 (2.2) |
| Nulliparous | 62 (15.6%) | 20 (27.0%) |
| Family history of breast cancer | 46 (11.6%) | 6 (8.1%) |
| Ever use oral contraceptive | 332 (83.4%) | 64 (86.5%) |
| Menopausal status | ||
| Premenopausal/dubious | 343 (86.2%) | 54 (73.0%) |
| Postmenopausal, no PMH | 41 (10.3%) | 15 (20.3%) |
| Postmenopausal, PMH | 14 (3.5%) | 5 (6.8%) |
| Alcohol | ||
| None | 176 (44.2%) | 25 (33.8%) |
| 0 to < 1.5 g/day | 68 (17.1%) | 15 (20.3%) |
| 1.5 to < 4.5 g/day | 85 (21.4%) | 14 (18.9%) |
| 4.5+ g/day | 69 (17.3%) | 20 (27.0%) |
| Age at menarche | ||
| < 11 years | 81 (20.4%) | 18 (24.3%) |
| 12 years | 123 (30.9%) | 22 (29.7%) |
| 13 years | 113 (28.4%) | 19 (25.7%) |
| 14+ years | 81 (20.4%) | 15 (20.3%) |
| Histologic categories of benign breast disease | ||
| Proliferative with no atypia | 365 (91.7%) | 65 (87.8%) |
| Atypical hyperplasia | 33 (8.3%) | 9 (12.2%) |
| Insulin-like growth factor 1 | ||
| Quartile 1 | 93 (23.4%) | 24 (32.4%) |
| Quartile 2 | 98 (24.6%) | 20 (27.0%) |
| Quartile 3 | 98 (24.6%) | 20 (27.0%) |
| Quartile 4 | 109 (27.4%) | 10 (13.5%) |
| Insulin-like growth factor binding protein-3 | ||
| Quartile 1 | 95 (23.9%) | 22 (29.7%) |
| Quartile 2 | 99 (24.9%) | 19 (25.7%) |
| Quartile 3 | 101 (25.4%) | 17 (23.0%) |
| Quartile 4 | 103 (25.9%) | 16 (21.6%) |
Data from the Nurses' Health Study II (1991 to 2002) presented as mean (standard deviation) or n (%). PMH, postmenopausal hormones.