Table 3. Ovarian cancer risk according to oral contraceptive use among carriers of BRCA1 or BRCA2 mutations.
| Cases (N=147) No. (%) | Controls (N=304) No. (%) | ORa | CIb | |
|---|---|---|---|---|
| Any usec | ||||
| No | 69 (46.9) | 116 (38.2) | 1.0 | — |
| Yes | 78 (53.1) | 188 (61.8) | 0.85 | 0.53–1.4 |
| Years of use | ||||
| <1 | 69 (46.9) | 116 (38.2) | 1.0 | — |
| 1–2 | 31 (21.1) | 40 (13.2) | 1.5 | 0.82–2.9 |
| 3–5 | 14 (9.5) | 44 (14.4) | 0.69 | 0.33–1.4 |
| 6+ | 33 (22.5) | 104 (34.2) | 0.62 | 0.35–1.1 |
| Trend per year of use among users | 0.95 | 0.91–0.99 |
a
OR=odds ratio, adjusted for study centre, parity and age.
b
CI=95% confidence interval.
c
For at least 1 year.