Table 1.

The number and percentage of women enrolled in WHEL across isoflavone category by demographic, medical, and tumor characteristics

Soy isoflavone intake, mg/dP
Baseline characteristicsLevel 1 (0–0.7), median = 0Level 2 (0.7–1.01), median = 0.3Level 3 (1.01–16.33), median = 4.8Level 4 (16.33–86.9), median = 26.7
n (%)(%)(%)(%)
Age, y0.008
 <45182 (37.9)192 (40)80 (16.7)26 (5.4)
 45–54440 (39)441 (39.1)180 (15.9)68 (6)
 55–60179 (37.9)194 (41.1)75 (15.9)24 (5.1)
 ≥60294 (44.9)267 (40.8)75 (11.5)19 (2.9)
Race/ethnicity<0.001
 White910 (39.0)951 (40.7)350 (15)123 (5.3)
 Black69 (65.7)26 (24.8)9 (8.6)1 (1)
 Hispanic91 (61.1)42 (28.2)12 (8.1)4 (2.7)
 Asian8 (9.5)45 (53.6)27 (32.1)4 (4.8)
 Othera17 (26.6)30 (46.9)12 (18.8)5 (7.8)
Education<0.001
 Some college625 (50.2)455 (36.6)128 (10.3)36 (2.9)
 College degree or higher470 (31.5)639 (42.8)282 (18.9)101 (6.8)
Menopausal status0.189
 Post- or perimenopausal985 (40.6)967 (39.9)357 (14.7)117 (4.8)
 Premenopausal108 (35.3)126 (41.2)52 (17)20 (6.5)
Baseline tamoxifen use0.321
 Current646 (39.3)668 (40.7)247 (15)81 (4.9)
 Never376 (42.5)334 (37.8)128 (14.5)46 (5.2)
 Past59 (33.9)81 (46.6)27 (15.5)7 (4)
ER/PR status0.127
 ER+ or PR+835 (38.9)865 (40.3)331 (15.4)113 (5.3)
 ER/PR238 (43.6)214 (39.2)74 (13.6)20 (3.7)
Stage0.25
 I430 (40.5)438 (41.2)143 (13.5)52 (4.9)
 II495 (39.5)489 (40.0)202 (16.1)68 (5.4)
 III170 (40.6)167 (39.9)65 (15.5)17 (3.3.)
Isoflavone supplementsb0.001
 Yes17 (29.3)16 (27.6)18 (31)7 (12.1)
 No1,078 (40.3)1,078 (40.3)392 (14.6)130 (4.9)

aPacific Islander, American Indian/mixed race.

bP value for differences of isoflavone intake between strata within category.