Table 2.
Histopathologic and clinicopathologic tumour characteristics of true, minimal signs, and missed screen-detected and interval breast cancers (proportions with 95% confidence intervals, CIs, unless otherwise specified)
| Tumour characteristic | Screen-detected breast cancers | Interval breast cancers | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| True | Minimal signs | Missed | True | Minimal signs | Missed | |||||||
| n = 457 | n = 336 | n = 229 | n = 310 | n = 254 | n = 224 | |||||||
| n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | |
| Type | ||||||||||||
| Invasive NSTa | 408 | 89.9 (86.7, 92.3) | 280 | 84.1 (79.8, 87.6) | 198 | 86.8 (81.8, 90.6) | 265 | 86.6 (82.3, 90.0) | 212 | 83.8 (78.8, 87.8) | 186 | 83.4 (78.0, 87.7) |
| Lobular | 35 | 7.7 (5.6, 10.5) | 37 | 11.1 (8.2, 14.9) | 20 | 8.8 (5.8, 13.2) | 35 | 11.4 (8.3, 15.5) | 33 | 13.0 (9.4, 17.8) | 26 | 11.7 (8.1, 16.5) |
| Other | 11 | 2.4 (1.4, 4.3) | 16 | 4.8 (3.0, 7.7) | 10 | 4.4 (2.4, 7.9) | 6 | 2.0 (0.9, 4.2) | 8 | 3.2 (1.6, 6.1) | 11 | 4.9 (2.8, 8.6) |
| Information not available | 3 | - | 3 | - | 1 | - | 4 | - | 1 | - | 1 | - |
| Tumour diameter (mm) | ||||||||||||
| Median (95% CI) | 457 | 12 (11, 13) | 336 | 13 (12, 14) | 229 | 13 (12, 14) | 310 | 19 (18, 20) | 254 | 20 (18, 22) | 224 | 20 (18, 22) |
| Histologic grade | ||||||||||||
| 1 | 103 | 22.9 (19.2, 27.0) | 111 | 33.0 (28.2, 38.2) | 73 | 32.3 (26.5, 38.6) | 26 | 8.5 (5.9, 12.2) | 43 | 17.3 (13.1, 22.5) | 30 | 13.8 (9.9, 19.0) |
| 2 | 212 | 47.1 (42.5, 51.7) | 175 | 52.1 (46.7, 57.4) | 122 | 54.0 (47.5, 60.4) | 137 | 44.8 (39.3, 50.4) | 116 | 46.6 (40.5, 52.8) | 109 | 50.2 (43.6, 56.8) |
| 3 | 135 | 30.0 (25.9, 34.4) | 50 | 14.9 (11.5, 19.1) | 31 | 13.7 (9.8, 18.8) | 143 | 46.7 (41.2, 52.3) | 90 | 36.1 (30.4, 42.3) | 78 | 35.9 (29.9, 42.5) |
| Information not available | 7 | - | 0 | - | 3 | - | 4 | - | 5 | - | 7 | - |
| Lymph node status | ||||||||||||
| Negative | 352 | 78.0 (74.0, 81.6) | 264 | 80.7 (76.1, 84.6) | 181 | 80.4 (74.8, 85.1) | 164 | 53.9 (48.3, 59.5) | 153 | 61.0 (54.8, 66.8) | 126 | 57.5 (50.9, 63.9) |
| Information not available | 6 | - | 9 | - | 4 | - | 6 | - | 3 | - | 5 | - |
| Subtype | ||||||||||||
| Luminal A-like | 121 | 29.0 (24.9, 33.5) | 114 | 37.4 (32.1, 42.9) | 76 | 36.4 (30.1, 43.1) | 31 | 11.0 (7.9, 15.2) | 45 | 19.7 (15.1, 25.4) | 52 | 25.0 (19.6, 31.3) |
| Luminal B-like | 239 | 57.3 (52.5, 62.0) | 174 | 57.0 (51.4, 62.5) | 123 | 58.9 (52.1, 65.3) | 175 | 62.3 (56.5, 67.7) | 141 | 61.8 (55.4, 67.9) | 118 | 56.7 (49.9, 63.3) |
| HER2+b (non-luminal) | 16 | 3.8 (2.4, 6.1) | 10 | 3.3 (1.8, 5.9) | 4 | 1.9 (0.7, 4.8) | 24 | 8.5 (5.8, 12.4) | 9 | 3.9 (2.1, 7.3) | 18 | 8.7 (5.5, 13.3) |
| Triple negative (ductal) | 41 | 9.8 (7.3, 13.1) | 7 | 2.3 (1.1, 4.7) | 6 | 2.9 (1.3, 6.1) | 51 | 18.1 (14.1, 23.1) | 33 | 14.5 (10.5, 19.6) | 20 | 9.6 (6.3, 14.4) |
| Information not available | 40 | - | 31 | - | 20 | - | 29 | - | 26 | - | 16 | - |
Note: 95% confidence intervals were calculated for proportions the Wilson score interval, and for medians using quantile regression with standard errors based on 100 bootstrap replications
aNST no special type
bHuman epidermal growth factor receptor 2 positive