Table 3. Estimated relative risks (RR) for breast cancer of the same histologic subgroup, and for breast cancer of any histology in second-degree relatives (SDR) of proband breast cancer cases by histologic subgroup.
CI: 95% confidence interval; Exp: expected; Obs: observed
| Same subgroup type | Any breast cancer | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Subgroup | #SDRs | Obs | Exp | P value | RR (CI) | Obs | Exp | P value | RR (CI) |
| Breast cancer | 559,835 | 7,395 | 5,916 | <0.001 | 1.25 (1.22, 1.28) | ||||
| Angiosarcoma | 294 | 0 | 0 | † | † | 0.56 | 1.29 (0.35, 3.32) | ||
| Apocrine | 1518 | 0 | 0.03 | 15 | 17.4 | 0.72 | 0.87 (0.48, 1.43) | ||
| Inflammatory | 4,983 | 0 | 0.33 | 66 | 49.9 | 0.03 | 1.32 (1.02, 1.68) | ||
| Lobular | 46,875 | 49 | 31.3 | 0.003 | 1.56 (1.16, 2.07) | 642 | 473.3 | <0.001 | 1.36 (1.25, 1.47) |
| Mucinous | 17,889 | 6 | 4.6 | 0.47 | 1.32 (0.48, 2.86) | 251 | 197.2 | 2.1e-4 | 1.27 (1.12, 1.44) |
| Phyllodes | 913 | 0 | 0.01 | 8 | 10.3 | 0.64 | 0.77 (0.33, 1.53) | ||
| Tubular | 4,252 | 0 | 0.21 | 52 | 42.9 | 0.17 | 1.21 (0.91, 1.59) | ||
| Medullary | 10,316 | 0 | 1.49 | 115 | 106.3 | 0.21 | 1.08 (0.89, 1.30) | ||
| Metaplastic | 981 | 0 | 0.01 | 13 | 10.4 | 0.25 | 1.24 (0.66, 2.13) | ||
†
Observed counts < 5 are censored