Table 1

Characteristics of treatment groups at randomizationa

CharacteristicsTamoxifen n = 36Placebo n = 33
Age at baseline (yr)50.9 ± 8.050.3 ± 6.4
At least one first-degree relative with breast cancer (%)7575.8
History of at least one breast biopsy (%)52.842.4
Nulliparity (%)36.124.2
Age at first live birthb (yr)26.1 ± 4.224.6 ± 4.6
Age at menarche (yr)12.8 ± 1.612.9 ± 1.7
Body mass index25.1 ± 3.125.3 ± 4.5
Alcohol consumption (drinks/week) 3.1 ± 4.5 3.9 ± 5.0
Wolfe’s parenchymal pattern (%)
N1 or P1 5.612.1
P252.851.5
DY41.736.4
Mean percentage of the breast with mammographic densities60.3 ± 18.560.5 ± 24.2
Duration of treatment (yr)3.3 ± 1.5 3.5 ± 1.2
  • a ± values are means ± SD.

  • b Among women who had at least one child.