Table 2.
Associations between statin use and breast cancer incidence in the Nurses’ Health Study, 2000–2012
| No. cases | Age-adjusted HR (95% CI) |
Multivariate* HR (95% CI) |
|||
|---|---|---|---|---|---|
| All invasive cases (n=3,055) | |||||
| Never-users | 1,977 | 1. | ref | 1. | ref |
| Former users | 202 | 0.93 | (0.80, 1.1) | 0.96 | (0.82, 1.1) |
| Current users: | |||||
| duration < 4y | 330 | 1.1 | (0.95, 1.2) | 1.0 | (0.92, 1.2) |
| 4y ≤ duration < 8y | 349 | 0.99 | (0.88, 1.1) | 0.95 | (0.84, 1.1) |
| duration ≥ 8y | 197 | 1.2 | (1.0, 1.4) | 1.1 | (0.92, 1.3) |
| Invasive ductal carcinoma (n=1,952) | |||||
| Never-users | 1,323 | 1. | ref | 1. | ref |
| Former users | 113 | 0.91 | (0.74, 1.1) | 0.92 | (0.75, 1.1) |
| Current users: | |||||
| duration < 4y | 212 | 1.0 | (0.87, 1.2) | 0.95 | (0.82, 1.1) |
| 4y ≤ duration < 8y | 214 | 0.94 | (0.81, 1.1) | 0.88 | (0.75, 1.0) |
| duration ≥ 8y | 90 | 1.1 | (0.88, 1.4) | 1.0 | (0.79, 1.3) |
| Invasive lobular carcinoma (n=313) | |||||
| Never-users | 206 | 1. | ref | 1. | ref |
| Former users | 18 | 0.86 | (0.52, 1.4) | 0.87 | (0.53, 1.4) |
| Current users | 89 | 1.1 | (0.82, 1.4) | 0.98 | (0.75, 1.3) |
| ER-positive cases (n=2,162) | |||||
| Never-users | 1,430 | 1. | ref | 1. | ref |
| Former users | 125 | 0.89 | (0.74, 1.1) | 0.90 | (0.75, 1.1) |
| Current users: | |||||
| duration < 4y | 245 | 1.1 | (0.95, 1.3) | 1.0 | (0.91, 1.2) |
| 4y ≤ duration < 8y | 249 | 0.98 | (0.85, 1.1) | 0.91 | (0.79, 1.0) |
| duration ≥ 8y | 113 | 1.2 | (0.94, 1.4) | 1.0 | (0.84, 1.3) |
| ER-negative cases (n=405) | |||||
| Never-users | 252 | 1. | ref | 1. | ref |
| Former users | 30 | 1.2 | (0.81, 1.8) | 1.3 | (0.85, 1.9) |
| Current users: | |||||
| duration < 4y | 41 | 1.1 | (0.77, 1.5) | 1.0 | (0.74, 1.5) |
| 4y ≤ duration < 8y | 56 | 1.2 | (0.88, 1.6) | 1.1 | (0.82, 1.5) |
| duration ≥ 8y | 26 | 1.6 | (1.0, 2.5) | 1.5 | (0.93, 2.3) |
| In situ cases (n=608) | |||||
| Never-users | 385 | 1. | ref | 1. | ref |
| Former users | 34 | 1.1 | (0.80, 1.6) | 1.2 | (0.83, 1.7) |
| Current users: | |||||
| duration < 4y | 82 | 1.4 | (1.1, 1.8) | 1.4 | (1.1, 1.7)** |
| 4y ≤ duration < 8y | 76 | 1.2 | (0.95, 1.6) | 1.1 | (0.88, 1.5) |
| duration ≥ 8y | 31 | 1.7 | (1.1, 2.5) | 1.5 | (0.99, 2.2) |
Adjusted for body mass (continuous), first-degree family history of breast cancer (dichotomous), personal history of benign breast disease (dichotomous), parity and age at first birth (design variables: see categories in methods section), age at menarche (<12, 12–13, or 14+), cumulative average ethanol consumption (design variables: see categories in methods section), MHT use (design variables: see categories in methods section), prevalent diabetes, and concomitant use of aspirin, ibuprofen, preventive tamoxifen, beta blockers, calcium channel blockers, ACE inhibitors, and digoxin.
This association was near-null in the subset of cohort members who had consistently undergone mammography screening (HRadj=1.2, 95% CI: 0.96, 1.6).