Table 2.
Histopathological tumor characteristics stratified by subgroups, in 231 interval cancers diagnosed in women aged 50–69 years, in the first screening round of the Norwegian Breast Cancer Screening Program
| Characteristics | Missed (n=80) | Minimal sign (n=53) | True1 (n=98) | All (n=231) | ||||
|---|---|---|---|---|---|---|---|---|
| No. | (%) | No. | (%) | No. | (%) | No. | (%) | |
| Histopathological type | ||||||||
| Ductal Carcinoma In Situ | 4 | (5) | 5 | (9) | 5 | (5) | 14 | (6) |
| Invasive ductal carcinoma | 54 | (68) | 40 | (75) | 76 | (78) | 170 | (74) |
| Invasive lobular carcinoma | 16 | (20) | 7 | (13) | 9 | (9) | 32 | (14) |
| Other invasive | 6 | (7) | 1 | (2) | 8 | (8) | 15 | (6) |
| Invasive cases | Invasive cases | Invasive cases | Invasive cases | |||||
| (n=76) | (n=48) | (n=93) | (n=217) | |||||
| Tumor size | ||||||||
| Mean mm | 23 mm2 | 22 mm | 18 mm | 21 mm | ||||
| Median mm | 20 mm | 20 mm | 16 mm | 20 mm | ||||
| <15mm (n, %) | 20 | (27) 2 | 15 | (33) | 41 | (47) | 76 | (37) |
| 15–20mm (n, %) | 19 | (26) | 10 | (22) | 16 | (18) | 45 | (22) |
| >20mm (n, %) | 34 | (47) | 21 | (46) | 30 | (34) | 85 | (41) |
| Missing/not available (n) | 3 | 2 | 6 | 11 | ||||
| Lymph node involvements | ||||||||
| Yes (n, %) | 34 | (49)2 | 24 | (53)2 | 27 | (33) | 85 | (43) |
| Missing/not available (n) | 6 | 3 | 10 | 19 | ||||
| Grading | ||||||||
| I (n, %) | 13 | (19) | 13 | (28) | 19 | (21) | 45 | (22) |
| II (n, %) | 39 | (57) | 20 | (43) | 47 | (52) | 106 | (51) |
| III (n, %) | 17 | (25) | 14 | (30) | 25 | (27) | 56 | (27) |
| Missing/not available (n) | 7 | 1 | 2 | 10 | ||||
| Receptor status | ||||||||
| Estrogen positive (n, %) | 42 | (67) | 25 | (64) | 56 | (67) | 123 | (66) |
| Missing/not available (n) | 13 | 9 | 10 | 32 | ||||
| Progesterone positive (n, %) | 31 | (49) | 20 | (56) | 39 | (47) | 90 | (49) |
| Missing/not available (n) | 13 | 12 | 10 | 35 | ||||
1
True interval cancers including occult cancers
2
Significantly different from true interval cancers at p<0.05