Table 4.

Duration and recency of unopposed estrogen only use

Duration of use (y)Time since last use
No use
Current use
Last use <5 y ago
Last use 5-9 y ago
Last use ≥10 y ago
No.RR (95% CI)No.RR (95% CI)No.RR (95% CI)No.RR (95% CI)No.RR (95% CI)
No use1681.0 (Reference)
<582.8 (1.4-5.8)91.5 (0.7-2.9)131.7 (0.96-3.0)321.5 (0.99-2.2)
5-91914.0 (8.5-23.0)53.6 (1.4-8.7)52.8 (1.1-6.8)82.3 (1.1-4.7)
≥103622.0 (14.9-32.5)86.2 (3.0-12.9)65.7 (2.5-13.0)32.3 (0.7-7.4)
Ave (y)6.44.63.83.0
    P<0.001<0.001<0.0010.007
Excess RR per year1.43(1.00-2.02)0.37(0.16-0.68)0.44(0.20-0.79)0.19(0.04-0.41)
  • NOTE: Restricted to women who never used hormones and women who used unopposed estrogens only. RRs adjusted for attained age, calendar time, household income, age at menarche, parity, duration of oral contraceptive use, current smoking, and BMI. Unknown duration or time since last use: 15 carcinomas (RR, 2.6; 95% CI, 1.5-4.4).