Table 1.
Age-standardized distributions of study matching factors and BBD lesion type among 78 breast cancer cases and 276 controls
| Variable | Breast cancer cases (n = 78) |
Controls (n = 276) |
|---|---|---|
| Age at cancer diagnosis, mean (SD) | 53.9 (8.7) | — |
| Year of BBD biopsy, % | ||
| Before 1980 | 41 | 40 |
| 1980–1989 | 48 | 46 |
| After 1989 | 11 | 15 |
| Time from BBD biopsy to index date, % | ||
| 0.5–4.9 years | 26 | 48 |
| 5.0–9.9 years | 39 | 24 |
| 10.0–14.9 years | 20 | 20 |
| 15.0+ years | 15 | 8 |
| BBD lesion type, % | ||
| Non-proliferative | 26 | 29 |
| Proliferative without atypia | 48 | 57 |
| Atypical hyperplasia | 26 | 15 |