Table 4. Associations of HRT ever-use and duration of use with risk of breast cancer subtypes defined by ER/PR/Her2 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 | a OR (95%CI) | Case/control | aOR (95%CI) | p for trend | |
| ER/PR/Her2 | |||||||||||
| Luminal A | |||||||||||
| BMI<25 | 19/99 | 1.00 (ref.) | 87/152 | 2.89 (1.64-5.10) | 22/48 | 2.59 (1.27-5.29) | 19/37 | 2.48 (1.18-5.26) | 34/51 | 3.05 (1.50-6.21) | 0.002 |
| BMI≥25 | 48/119 | 1.00 (ref.) | 75/214 | 0.83 (0.54-1.28) | 22/75 | 0.69 (0.38-1.25) | 19/48 | 0.95 (0.50-1.79) | 26/56 | 1.06 (0.59-1.92) | 0.840 |
| bp for interaction < 0.001 | cp for interaction = 0.019 | ||||||||||
| Luminal B/Her2 overexpression | |||||||||||
| BMI<25 | 9/99 | 1.00 (ref.) | 22/152 | 1.71 (0.74-3.93) | 5/48 | 1.19 (0.38-3.79) | 7/37 | 2.18 (0.75-5.38) | 9/51 | 2.24 (0.76-6.59) | 0.092 |
| BMI≥25 | 26/119 | 1.00 (ref.) | 23/214 | 0.52 (0.28-0.96) | 11/75 | 0.66 (0.31-1.44) | 3/48 | 0.29 (0.09-1.02) | 6/56 | 0.65 (0.24-1.73) | 0.109 |
| bp for interaction = 0.009 | cp for interaction = 0.004 | ||||||||||
| Triple negative | |||||||||||
| BMI<25 | 7/99 | 1.00 (ref.) | 12/152 | 1.12 (0.42-3.00) | 2/48 | 0.58 (0.11-2.91) | 2/37 | 0.79 (0.16-4.04) | 6/51 | 1.79 (0.51-6.36) | 0.442 |
| BMI≥25 | 11/119 | 1.00 (ref.) | 20/214 | 1.12 (0.51-2.44) | 3/75 | 0.51 (0.14-1.89) | 7/48 | 1.61 (0.58-4.44) | 5/56 | 1.08 (0.34-3.42) | 0.572 |
| bp for interaction = 0.862 | cp for interaction = 0.637 | ||||||||||
a
Adjusted for age and education.
b
Interaction between HRT ever-use and BMI (<25 or ≥25) for risk of for risk of luminal A, luminal B/Her2 overexpression, and triple-negative subtypes, respectively.
c
Interaction between duration of HRT ever-use and BMI (<25 or ≥25) for risk of luminal A, luminal B/Her2 overexpression, and triple-negative subtypes, respectively.