Table 2.
Risk of Breast Cancer Associated With Migraine History
| Breast Cancer Type | No. of Incident Cases Without a Migraine History | No. of Incident Cases With a Migraine History | Adjusted for Age and Race/Ethnicity |
Multivariate Adjusted Analysis* |
||
|---|---|---|---|---|---|---|
| HR | 95% CI | HR | 95% CI | |||
| Any breast cancer | 3,595 | 411 | 0.89 | 0.80 to 0.98† | 0.89 | 0.80 to 0.98† |
| In situ breast cancer | 623 | 65 | 0.80 | 0.62 to 1.03 | 0.81 | 0.62 to 1.05 |
| Invasive breast cancer | 2,972 | 346 | 0.91 | 0.81 to 1.01 | 0.90 | 0.80 to 1.01 |
| ER/PR status | ||||||
| ER and PR positive | 1,693 | 185 | 0.85 | 0.73 to 0.99† | 0.83 | 0.71 to 0.97† |
| ER positive and PR negative | 361 | 42 | 0.89 | 0.65 to 1.23 | 0.92 | 0.66 to 1.28 |
| ER and PR negative | 335 | 53 | 1.22 | 0.91 to 1.63 | 1.16 | 0.86 to 1.57 |
| Histology | ||||||
| Ductal | 1,709 | 207 | 0.94 | 0.81 to 1.08 | 0.91 | 0.79 to 1.06 |
| Lobular | 678 | 76 | 0.87 | 0.69 to 1.10 | 0.88 | 0.69 to 1.13 |
| Other | 359 | 33 | 0.73 | 0.51 to 1.05 | 0.72 | 0.50 to 1.04 |
Abbreviations: HR, hazard ratio; ER, estrogen receptor; PR, progesterone receptor.
*
Multivariate adjusted HRs are adjusted for age, race/ethnicity, and the following baseline characteristics: hysterectomy, use of menopausal hormones, nonsteroidal anti-inflammatory drug use/duration, alcohol consumption, smoking status, and regular coffee consumption. The 3,333 women missing data for one or more of the covariates adjusted for in the multivariate models were excluded from these analyses.
†
P < .05.