Table 1.

Characteristics of study participants

Cases, n (%)Controls, n (%)
Age (y)
    <50140 (23)149 (23)
    ≥50468 (77)501 (77)
Menopausal status
    Premenopausal146 (24)148 (23)
    Postmenopausal455 (76)495 (77)
Smoking status
    Never351 (58)362 (56)
    Former139 (23)137 (21)
    Current117 (19)151 (23)
Breast cancer in mother or sisters
    No537 (88)601 (93)
    Yes71 (12)49 (8)
Parity
    0123 (20)120 (19)
    ≥1485 (80)529 (82)
HRT (y)
    Never295 (49)327 (51)
    >0 to <10152 (25)188 (29)
    ≥10153 (26)130 (20)