Screen-detected breast cancer | Interval breast cancer | |||||
---|---|---|---|---|---|---|
Baseline risk factor | No. of controls (%) | No. of cases (%) | Odds ratioa(95% CI) | No. of cases (%) | Odds ratioa(95% CI) | |
Age at first live birthb | ||||||
5-year increase | 4,048 (86.8) | 705 (81.0) | 1.11 (1.00-1.23) | 202 (84.2) | 1.17 (0.98-1.41) | |
Nulliparous | 618 (13.2) | 165 (19.0) | 1.38 (1.12-1.70) | 38 (15.8) | 1.14 (0.77-1.70) | |
Age at menopausec | ||||||
5-year increase | 3,040 (65.2) | 573 (65.9) | 1.17 (1.05-1.31) | 121 (50.4) | 1.18 (0.92-1.50) | |
Premenopausal | 1,626 (34.8) | 297 (34.1) | 1.04 (0.82-1.32) | 119 (49.6) | 1.56 (1.02-2.38) | |
Family history of breast cancer | ||||||
None | 4,055 (86.9) | 712 (81.8) | 1.00 (reference) | 184 (76.7) | 1.00 (reference) | |
Second-degree relative | 325 (7.0) | 75 (8.6) | 1.24 (0.95-1.63) | 28 (11.7) | 1.83 (1.16-2.87) | |
First-degree relative ≥50 years | 172 (3.7) | 49 (5.6) | 1.49 (1.06-2.10) | 13 (5.4) | 1.55 (0.80-2.97) | |
First-degree relative <50 years | 114 (2.4) | 34 (3.9) | 1.57 (1.05-2.36) | 15 (6.3) | 2.83 (1.53-5.22) | |
Previous breast biopsy | ||||||
No | 4,263 (91.4) | 747 (85.9) | 1.00 (reference) | 200 (83.3) | 1.00 (reference) | |
Yes | 403 (8.6) | 123 (14.1) | 1.48 (1.18-1.86) | 40 (16.7) | 1.99 (1.34-2.96) | |
Mammographic density (%) | ||||||
0-10 | 1,710 (36.6) | 220 (25.3) | 1.00 (reference) | 32 (13.3) | 1.00 (reference) | |
11-25 | 1,136 (24.3) | 188 (21.6) | 1.30 (1.05-1.62) | 46 (19.2) | 1.95 (1.20-3.17) | |
26-50 | 1,157 (24.8) | 273 (31.4) | 2.00 (1.62-2.47) | 87 (36.3) | 3.54 (2.24-5.60) | |
51-75 | 528 (11.3) | 155 (17.8) | 2.45 (1.89-3.17) | 52 (21.7) | 4.25 (2.53-7.14) | |
>75 | 135 (2.9) | 34 (3.9) | 2.17 (1.40-3.36) | 23 (9.6) | 7.72 (4.02-14.81) | |
P value for trendd | <0.001 | < 0.001 |