Table 6.
Associations Between Estrogen Plus Progestin (EPT) Use Among Women with Intact Uteri and Breast Cancer Risk by Combinations of Tumor Characteristics, NIH-AARP Diet and Health Study Cohort
| Estrogen Receptor (ER) Status | Histology | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ER− |
ER+ |
Ductal |
Lobular |
Mixed Ductal/lobular |
|||||||||||
| N | RR* | 95% CI | N | RR* | 95% CI | N | RR* | 95% CI | N | RR* | 95% CI | N | RR* | 95% CI | |
| Histology | |||||||||||||||
| Ductal | 96 | 1.02 | 0.63–1.64 | 472 | 2.61 | 2.10–3.24 | |||||||||
| Lobular | 5 | 5.20 | 0.48–56.84 | 90 | 2.23 | 1.36–3.67 | |||||||||
| Mixed | 6 | 2.54 | 0.39–16.69 | 83 | 6.37 | 3.45–11.79 | |||||||||
| Grade | |||||||||||||||
| Grade 1 | 10 | 1.00 | 0.25–4.05 | 222 | 5.94 | 4.11–8.47 | 266 | 3.63 | 2.69–4.90 | 24 | 4.95 | 1.52–16.10 | 37 | 3.67 | 1.63–8.25 |
| Grade 2 | 26 | 3.26 | 1.22–8.75 | 313 | 2.37 | 1.83–3.09 | 515 | 1.53 | 1.25–1.87 | 62 | 1.78 | 0.99–3.21 | 70 | 4.82 | 2.63–8.85 |
| Grade 3 | 78 | 1.18 | 0.70–1.98 | 137 | 2.61 | 1.74–3.91 | 329 | 1.44 | 1.11–1.87 | 23 | 2.19 | 0.88–5.45 | 26 | 1.13 | 0.44–2.91 |
*
RRs adjusted for age (continuous) and for race, age at first birth, menopausal status, number of breast biopsies, family history of breast cancer, and number of mammograms (per categorizations shown in Table 1). Models also include terms for other HT formulations. Referent group for RRs are non-users of EPT.