Table I.
Distribution of selected variables among sisters affected and unaffected with breast cancer in the Breast Cancer Family Registry (BCFR).
| Variable | No. cases (%) (n=219) |
No. controls (%) (n=271) |
p-Valuea |
|---|---|---|---|
| Age at blood draw (in years) | |||
| ≤50 | 127 (58.0) | 172 (63.5) | 0.22 |
| >50 | 92 (42.0) | 99 (36.5) | |
| BRCA1 (+) mutation | 12 (5.5) | 8 (3.0) | 0.16 |
| BRCA2 (+) mutation | 10 (4.6) | 5 (1.8) | 0.08 |
| Ethnicity | |||
| Non-Hispanic White | 117 (54.2) | 127 (47.0) | 0.27 |
| African American | 5 (2.3) | 9 (3.3) | |
| Other | 94 (43.5) | 134 (49.6) | |
| Smoking Status | |||
| Never | 129 (58.9) | 164 (60.5) | 0.72 |
| Ever | 90 (41.1) | 107 (39.5) | |
| BMI (kg/m2) | |||
| <25 | 106 (48.4) | 127 (47.4) | 0.82 |
| ≥25 | 113 (51.6) | 141 (52.6) | |
| Age at menarche (in years) | |||
| <13 | 101 (46.3) | 117 (43.2) | 0.49 |
| ≥13 | 117 (53.7) | 154 (56.8) | |
| Parity | |||
| Nulliparous | 39 (17.8) | 52 (19.2) | 0.70 |
| Parous | 180 (82.2) | 219 (80.8) | |
| Family History | |||
| 1 | 122 (55.7) | 172 (63.5) | 0.08 |
| >1 | 97 (44.3) | 99 (36.5) |
a
Pearson’s χ2-test; BMI, body mass index.