Table 5.
Association of absolute change in sex hormone levels from baseline to year 1 with breast cancer risk in the Women’s Health Initiative estrogen plus progestin trial
| Sex hormone | Number of case subjects, number of control subjects | Odds ratio (95% confidence interval)* |
|---|---|---|
| Change in total estradiol, pg/mL | ||
| Quartile (Q)1 (<−2.39) | 75, 73 | 1.00 (referent) |
| Q2 (−2.4 to 1.99) | 68, 89 | 0.70 (0.40 to 1.28) |
| Q3 (2.00–13.29) | 76, 67 | 1.23 (0.65 to 2.30) |
| Q4 (13.30–150.30) | 80, 70 | 1.14 (0.67 to 2.30) |
| P trend | .39 | |
| Change in bioavailable estradiol, pg/mL | ||
| Q1 (<−19.4) | 76, 65 | 1.00 (referent) |
| Q2 (−19.5 to 0.27) | 64, 83 | 0.81 (0.44 to 1.49) |
| Q3 (0.28–4.21) | 82, 67 | 1.29 (0.69 to 2.39) |
| Q4 (4.22–91.14) | 70, 74 | 0.95 (0.50 to 1.80) |
| P trend | .84 | |
| Change in estrone, pg/mL | ||
| Q1 (<−3.89) | 76, 67 | 1.00 (referent) |
| Q2 (−3.90 to 13.69) | 63, 97 | 0.62 (0.30 to 1.14) |
| Q3 (13.70–97.19) | 82, 75 | 0.77 (0.39 to 1.51) |
| Q4 (97.20–715.62) | 81, 63 | 0.78 (0.36 to 1.71) |
| P trend | .63 | |
| Change in estrone sulfate, ng/mL | ||
| Q1 (<−0.14) | 57, 67 | 1.00 (referent) |
| Q2 (−0.15 to 0.13) | 58, 72 | 0.78 (0.40 to 1.54) |
| Q3 (0.14–1.17) | 70, 63 | 1.33 (0.69 to 2.58) |
| Q4 (1.18–9.81) | 78, 61 | 1.38 (0.62 to 3.08) |
| P trend | .29 | |
| Change in sex hormone–binding globulin, ng/dL | ||
| Q1 (<−0.2) | 63, 79 | 1.00 (referent) |
| Q2 (−0.3 to 12.24) | 67, 84 | 0.93 (0.53 to 1.64) |
| Q3 (12.25–61.89) | 96, 77 | 1.37 (0.71 to 2.62) |
| Q4 (61.90–251.00) | 79, 65 | 1.63 (0.77 to 3.43) |
| P trend | .22 | |
* Adjusted for treatment assignment, baseline sex hormone level, age at menarche, body mass index, and family history of breast cancer. Results were obtained using conditional logistic regression models. All statistical tests were two-sided.