Table 2.
Association of baseline sex hormone levels with invasive breast cancer risk
| Sex hormone | Number of case subjects, number of control subjects | Odds ratio (95% confidence interval)* |
|---|---|---|
| Total estradiol† | ||
| Quartile (Q)1 (2.5–7.94) | 27, 60 | 1.00 (referent) |
| Q2 (7.95–10.89) | 42, 41 | 2.07 (1.06 to 4.04) |
| Q3 (10.90–14.99) | 37, 43 | 1.58 (0.77 to 3.21) |
| Q4 (15.00–39.20) | 38, 31 | 2.52 (1.12 to 5.63) |
| P trend | .04 | |
| Bioavailable estradiol† | ||
| Q1 (1.58–4.99) | 29, 57 | 1.00 (referent) |
| Q2 (5.00–7.14) | 37, 43 | 1.58 (0.75 to 3.29) |
| Q3 (7.15–10.52) | 37, 46 | 1.35 (0.66 to 2.75) |
| Q4 (10.53–29.30) | 41, 28 | 2.82 (1.25 to 6.36) |
| P trend | .03 | |
| Estrone† | ||
| Q1 (9.05–27.86) | 31, 56 | 1.00 (referent) |
| Q2 (27.87–36.78) | 40, 44 | 1.87 (0.92 to 3.80) |
| Q3 (36.79–50.38) | 34, 43 | 2.19 (1.03 to 4.66) |
| Q4 (50.39–151.39) | 42, 34 | 3.01 (1.34 to 6.76) |
| P trend | .007 | |
| Estrone sulphate | ||
| Q1 (0.23–0.56) | 71, 93 | 1.00 (referent) |
| Q2 (0.57–0.76) | 70, 74 | 1.41 (0.83 to 2.39) |
| Q3 (0.77–1.034) | 87, 70 | 2.23 (1.23 to 4.02) |
| Q4 (1.035–2.75) | 86, 77 | 2.38 (1.20 to 4.72) |
| P trend | .007 | |
| Progesterone | ||
| Q1 (11.66–40.44) | 81, 77 | 1.00 (referent) |
| Q2 (40.45–58.87) | 83, 85 | 0.89 (0.54 to 1.45) |
| Q3 (58.87–83.49) | 88, 84 | 0.94 (0.56 to 1.58) |
| Q4 (83.50–498.7) | 88, 94 | 0.96 (0.56 to 1.67) |
| P trend | .96 | |
| Total testosterone | ||
| Q1 (3.84–16.59) | 64, 71 | 1.00 (referent) |
| Q2 (16.60–22.57) | 76, 95 | 0.84 (0.50 to 1.41) |
| Q3 (22.58–31.38) | 96, 78 | 1.34 (0.79 to 2.28) |
| Q4 (31.39–118.42) | 106, 98 | 1.08 (0.65 to 1.80) |
| P trend | .35 | |
| Bioavailable testosterone | ||
| Q1 (0.51–8.30) | 72, 70 | 1.00 (referent) |
| Q2 (8.31–11.50) | 70, 92 | 0.74 (0.44 to 1.26) |
| Q3 (11.51–16.05) | 86, 87 | 1.01 (0.60 to 1.68) |
| Q4 (16.06–81.11) | 110, 89 | 1.11 (0.66 to 1.86) |
| P trend | .38 | |
| Sex hormone–binding globulin | ||
| Q1 (6.9–27.89) | 80, 77 | 1.00 (referent) |
| Q2 (27.90–39.54) | 94, 69 | 1.45 (0.87 to 2.42) |
| Q3 (39.55–54.99) | 77, 104 | 0.79 (0.48 to 1.30) |
| Q4 (55.00–159.00) | 91, 92 | 1.05 (0.62 to 1.79) |
| P trend | .54 | |
* Adjusted for treatment assignment, 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.
† Total estradiol, bioavailable estradiol, and estrone estimates were obtained from the placebo group, due to their statistically significant interactions with estrogen + progestin treatment.