Table 1.

The distribution of patient characteristics.

Age at breast cancer onset
28–40 years	37 (6.2%)
41–74 years	511 (86.0%)
75–87 years	46 (7.7%)
Median	58 years
Age at menarche
10–12 years	159 (26.8%)
13–14 years	205 (34.5%)
15–17 years	97 (16.3%)
Missing	133 (22.4%)
Median	13 years
Menopausal status
Premenopausal	156 (26.3%)
Perimenopausal	10 (1.7%)
Postmenopausal	390 (65.7%)
Missing	38 (6.4%)
Median age at menopause	48 years
Number of deliveries before breast cancer diagnosis
0	67 (11.3%)
1	77 (13.0%)
2	186 (31.3%)
3	118 (19.9%)
4	45 (7.6%)
≥ 5	41 (6.9%)
Missing	60 (10.1%)
Median number of deliveries	2