From: Tissue-based associations of mammographic breast density with breast stem cell markers
Characteristic | Mean (STD) or number (percentage) |
---|---|
Age at mammogram (continuous, years) | 51.1 (9.6) |
Body mass index (continuous, kg/m2) | 27.0 (4.7) |
Parity and age at first child’s birth | |
 Nulliparous | 10 (16%) |
 1–4 children with age at first birth ≤ 24 years | 24 (38%) |
 1–4 children with age at first birth of 25–29 years | 13 (20%) |
 1–4 children with age at first birth of ≥ 30 years | 15 (23%) |
  ≥ 5 children with age at first birth of < 25 years | 0 (0%) |
  ≥ 5 children with age at first birth of ≥ 25 years | 2 (3%) |
Menopausal status | |
 Premenopausal | 22 (34%) |
 Postmenopausal | 42 (66%) |
Postmenopausal hormone use | |
 Never | 28 (67%) |
 Past | 13 (31%) |
 Current | 0 (0%) |
 Unknown | 1 (2%) |
Family history of breast or ovarian cancer in first-degree relativesa | 26 (43%) |