Table 2.
Characteristics of women with breast cancer
| Screen detected cancer | Interval cancer | |||||
|---|---|---|---|---|---|---|
| Advanced N = 570 |
Non-advanced N = 1,164 |
P- value |
Advanced N = 424 |
Non-advanced N = 233 |
P- value |
|
| Mean age, years (95%CI) | 62.0 (61.3 - 62.6) | 62.4 (62.0 - 62.8) | 0.24 | 59.5 (58.9 - 60.2) | 59.3 (58.4 - 60.2) | 0.76 |
| Family history of breast cancer±, No (%) | 123 (21.6) | 218 (18.7) | 0.16 | 76 (17.9) | 43 (18.5) | 0.87 |
| Previous breast surgery# | 58 (10.0) | 130 (11.2) | 0.53 | 72 (15.6) | 34 (15.0) | 0.43 |
| Use of hormone replacement therapy, No (%) | 59 (10.4) | 95 (8.2) | 0.13 | 70 (13.1) | 20 (6.3) | 0.005 |
| Initial screens, No (%) | 106 (18.6) | 183 (15.7) | 0.13 | 64 (13.5) | 32 (11.8) | 0.64 |
| Interval between 2 latest screens, No (%) | 0.08 | - | - | |||
| < 30 months | 527 (92.5) | 1,101 (94.6) | ||||
| ≥ 30 months | 43 (7.5) | 63 (5.4) | ||||
| Breast density at latest screening mammogram, No (%) | 0.45 | 0.49 | ||||
| ≤ 50% | 375 (65.8) | 787 (67.4) | 243 (60.7) | 140 (60.1) | ||
| > 50% | 195 (34.2) | 377 (32.4) | 181 (39.3) | 93 (39.9) | ||
| Mammographic abnormality, No (%) | < 0.001 | 0.04 | ||||
| Density | 426 (74.8) | 740 (63.6) | 133 (64.6) | 78 (70.9) | ||
| Microcalcifications | 35 (6.1) | 280 (24.1) | 26 (12.6) | 18 (16.4) | ||
| Density with microcalcifications | 82 (14.4) | 112 (9.6) | 16 (7.8) | 6 (5.5) | ||
| Architectural distortion | 22 (3.9) | 24 (2.1) | 11 (5.3) | 7 (6.4) | ||
| Breast parenchyma asymmetry | 4 (0.9) | 8 (0.7) | 20 (9.7) | 1 (0.9) | ||
| Breast cancer visible at previous screening mammogram | 199 (42.9)* | 418 (42.7)¥ | 0.95 | 208 (47.6) | 112 (47.4) | 0.81 |
| Tumor histology of invasive cancers, No (%) | < 0.001 | 0.09 | ||||
| Ductal | 414 (72.6) | 682 (77.7) | 304 (71.8) | 155 (77.7) | ||
| Lobular | 93 (16.3) | 85 (9.7) | 87 (21.3) | 30 (10.9) | ||
| Mixed ductal-lobular | 37 (6.5) | 41 (4.7) | 18 (4.0) | 10 (5.9) | ||
| Invasive other | 24 (4.2) | 68 (7.7) | 11 (2.0) | 11 (5.5) | ||
| Unknown | 2 (0.4) | 2 (0.2) | 4 (0.9) | 0 (0.0) | ||
±At least one first-degree relative (mother, sister, daughter) with a diagnosis of breast cancer before the age of 50 years or at least two second-degree relatives with breast cancer. #Surgery for benign conditions (e.g., excisional biopsy, breast reduction, breast augmentation, mastitis) and malignant conditions (lumpectomy, mastectomy). *464 subsequent screens; ¥979 subsequent screens