Table 3.
Tumour and treatment characteristics of contralateral invasive breast cancers after primary DCIS by MRI use and moment of detection, n (%)
| Characteristics | MRI group | MRI group | Age-matched controls | |||
|---|---|---|---|---|---|---|
| Synchronous (n = 21) | Metachronous (n = 47) | p value$ | Total (n = 68) | Total (n = 56) | p value† | |
| Age at diagnosis, median (IQR) years | 59 (52–66) | 57 (52–65) | 0.64 | 57 (52–65) | 54 (49–62) | 0.07 |
| Histology | 0.85 | 0.13 | ||||
| Ductal | 14 (67%) | 33 (70%) | 47 (69%) | 40 (71%) | ||
| (Mixed) lobular | 4 (19%) | 3 (13%) | 10 (15%) | 13 (23%) | ||
| Other invasive | 3 (14%) | 8 (17%) | 11 (16%) | 3 (5%) | ||
| pT stage | 0.77 | 0.35 | ||||
| pT1 | 15 (71%) | 27 (59%) | 42 (63%) | 39 (70%) | ||
| pT2 | 5 (24%) | 16 (35%) | 21 (31%) | 12 (21%) | ||
| pT3 | 1 (5%) | 2 (4%) | 3 (5%) | 5 (9%) | ||
| pT4 | 0 (0%) | 1 (2%) | 1 (2%) | 0 (0%) | ||
| Unknown | n = 0 | n = 1 | n = 1 | n = 0 | ||
| Pathological tumour size | ||||||
| Median (IQR), mm | 12 (4–20) | 13 (6–25) | 0.29 | 13 (8–23) | 12 (7–17) | 0.37 |
| < 15 mm | 12 (60%) | 23 (52%) | 0.83 | 35 (55%) | 31 (62%) | 0.49 |
| 15–30 mm | 5 (25%) | 11 (25%) | 16 (25%) | 13 (26%) | ||
| > 30 mm | 3 (15%) | 10 (23%) | 13 (20%) | 6 (12%) | ||
| Unknown | n = 1 | n = 3 | n = 4 | n = 6 | ||
| N stage | 1.00 | 1.00 | ||||
| pN0 | 15 (75%) | 35 (74%) | 50 (75%) | 42 (75%) | ||
| pN+ | 5 (25%) | 12 (26%) | 17 (25%) | 14 (25%) | ||
| Unknown | n = 1 | n = 0 | n = 1 | n = 0 | ||
| M stage | 0.30 | 0.69 | ||||
| M0 | 21 (100%) | 43 (91%) | 64 (94%) | 54 (96%) | ||
| M1 | 0 (0%) | 4 (9%) | 4 (6%) | 2 (4%) | ||
| Subtype | 0.17 | 0.28 | ||||
| HR+/HER2− | 18 (90%) | 33 (73%) | 51 (79%) | 47 (86%) | ||
| HR+/HER2+ | 1 (5%) | 1 (2%) | 2 (3%) | 4 (7%) | ||
| HR−/HER2+ | 1 (5%) | 3 (7%) | 4 (6%) | 1 (2%) | ||
| HR−/HER2− (TN) | 0 (0%) | 8 (18%) | 8 (12%) | 3 (9%) | ||
| Unknown | n = 1 | n = 2 | n = 3 | n = 1 | ||
| Grade | 0.002 | 0.40 | ||||
| Low | 10 (53%) | 4 (10%) | 14 (23%) | 15 (28%) | ||
| Intermediate | 7 (37%) | 25 (61%) | 32 (53%) | 31 (59%) | ||
| High | 2 (10%) | 12 (29%) | 14 (23%) | 7 (13%) | ||
| Unknown | n = 2 | n = 6 | n = 8 | n = 3 | ||
| Surgery | 20 (95%) | 43 (91%) | 1.00 | 63 (93%) | 54 (96%) | 0.46 |
| BCS | 8 (38%) | 18 (38%) | 26 (38%) | 21 (37%) | ||
| Mastectomy | 12 (57%) | 25 (52%) | 0.80 | 37 (54%) | 33 (59%) | 0.72 |
| None | 1 (5%) | 4 (9%) | 5 (7%) | 2 (4%) | ||
| Radiotherapy | 10 (48%) | 26 (55%) | 0.61 | 36 (53%) | 25 (45%) | 0.37 |
| Systemic treatment | 11 (52%) | 30 (64%) | 0.43 | 41 (60%) | 32 (57%) | 0.86 |
| Chemotherapy | 5 (24%) | 15 (32%) | 0.58 | 20 (29%) | 14 (25%) | 0.69 |
| Endocrine therapy | 10 (48%) | 23 (49%) | 1.00 | 33 (49%) | 27 (48%) | 1.00 |
| Targeted therapy | 2 (10%) | 4 (9%) | 1.00 | 6 (9%) | 5 (9%) | 1.00 |
Percentages may not add up to 100 because of rounding
BCS breast-conserving surgery, HER2 human epidermal growth factor receptor 2, HR hormone receptor, IQR interquartile range
$Comparison of synchronous with metachronous contralateral invasive breast cancer in the MRI group
†Comparison of all contralateral invasive breast cancers in the MRI group versus the age-matched controls