Table 3. Associations of HRT ever-use and duration of use with risk of breast cancer subtypes defined by ER or ER/PR status among women with natural menopause, the Nashville Breast Health Study.
| Variables | Ever use of HRT | Duration of HRT use | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Nonusers | Ever-users | < 5 years | 5-9 years | ≥ 10 years | |||||||
| Case/control | aOR (95%CI) | Case/control | a OR (95%CI) | Case/control | aOR (95%CI) | Case/control | aOR (95%CI) | Case/control | aOR (95%CI) | p for trend | |
| ER status | |||||||||||
| ER+ | |||||||||||
| BMI<25 | 32/99 | 1.00 (ref.) | 122/152 | 2.52 (1.56-4.05) | 31/48 | 2.210(1.19-4.05) | 30/37 | 2.41 (1.28-4.55) | 47/51 | 2.82 (1.52-5.22) | < 0.001 |
| BMI≥25 | 76/119 | 1.00 (ref.) | 120/214 | 0.87 (0.60-1.25) | 40/75 | 0.82 (0.51-1.33) | 30/48 | 0.97 (0.56-1.66) | 36/56 | 0.98 (0.58-1.56) | 0.940 |
| bp for interaction < 0.001 | cp for interaction < 0.001 | ||||||||||
| ER- | |||||||||||
| BMI<25 | 15/99 | 1.00 (ref.) | 26/152 | 1.12 (0.55-2.25) | 6/48 | 0.82 (0.30-2.27) | 6/37 | 1.08 (0.39-3.01) | 12/51 | 1.60 (0.64-4.02) | 0.341 |
| BMI≥25 | 27/119 | 1.00 (ref.) | 35/214 | 0.78 (0.45-1.37) | 11/75 | 0.72 (0.33-1.55) | 9/48 | 0.87 (0.38-2.01) | 9/56 | 0.86 (0.37-2.04) | 0.693 |
| bp for interaction =0.231 | cp for interaction = 0.092 | ||||||||||
| ER/PR status | |||||||||||
| ER+PR+ | |||||||||||
| BMI<25 | 23/99 | 1.00 (ref.) | 94/152 | 2.69 (1.58-4.60) | 19/48 | 1.90 (0.93-3.84) | 21/37 | 2.35 (1.15-4.78) | 42/51 | 3.50 (1.78-6.86) | < 0.001 |
| BMI≥25 | 61/119 | 1.00 (ref.) | 97/214 | 0.88 (0.59-1.30) | 32/75 | 0.82 (0.49-1.37) | 24/48 | 0.96 (0.54-1.72) | 30/56 | 1.02 (0.58-1.79) | 0.951 |
| bp for interaction < 0.001 | cp for interaction <0.001 | ||||||||||
| ER-PR- | |||||||||||
| BMI<25 | 13/99 | 1.00 (ref.) | 24/152 | 1.15 (0.55-2.41) | 5/48 | 0.81 (0.27-2.43) | 5/37 | 1.00 (0.33-3.03) | 12/51 | 1.68 (0.66-4.32) | 0.315 |
| BMI≥25 | 27/119 | 1.00 (ref.) | 34/214 | 0.77 (0.44-1.36) | 10/75 | 0.65 (0.30-1.44) | 9/48 | 0.87 (0.38-2.01) | 9/56 | 0.87 (0.37-2.05) | 0.704 |
| bp for interaction = 0.173 | cp for interaction = 0.058 | ||||||||||
a
Adjusted for age and education.
b
Interaction between HRT ever-use and BMI (<25 or ≥25) for risk of ER+, ER-, ER+PR+, and ER-PR- tumors, respectively.
c
Interaction between duration of HRT use and BMI (<25 or ≥25) for risk of ER+, ER-, ER+PR+, and ER-PR- tumors, respectively.