Table 1.
Baseline characteristics of patients diagnosed with early-stage breast cancer in Denmark and the Netherlands who underwent a breast-contour preserving procedure or mastectomy alone between 2012 and 2017
| Denmark (n = 21,288) | Netherlands (n = 71,593) | |||||||
|---|---|---|---|---|---|---|---|---|
| Breast-contour preservation | Breast-contour preservation | |||||||
| N (col %) | No (row %) | Yes (row %) | p value | N (col %) | No (row %) | Yes (row %) | p value | |
| Number of patients | 21,288 | 23.3 | 76.7 | 71,593 | 25.5 | 74.5 | ||
| Year of operation | ||||||||
| 2012 | 3455 (16.2) | 24.2 | 75.8 | 0.25 | 11,412 (15.9) | 30.5 | 69.5 | < 0.001 |
| 2013 | 3568 (16.8) | 24.1 | 75.9 | 11,586 (16.2) | 29.0 | 71.0 | ||
| 2014 | 3617 (17.0) | 22.3 | 77.7 | 11,985 (16.7) | 27.0 | 73.0 | ||
| 2015 | 3552 (16.7) | 22.4 | 77.6 | 11,889 (16.6) | 24.3 | 75.7 | ||
| 2016 | 3529 (16.6) | 23.4 | 76.6 | 12,313 (17.2) | 21.4 | 78.6 | ||
| 2017 | 3567 (16.8) | 23.2 | 76.8 | 12,408 (17.3) | 21.5 | 78.5 | ||
| Age (years) | ||||||||
| < 40 | 838 (3.9) | 30.8 | 69.2 | < 0.001 | 2850 (4.0) | 22.5 | 77.5 | < 0.001 |
| 40–49 | 2857 (13.4) | 25.3 | 74.7 | 9818 (13.7) | 23.0 | 77.0 | ||
| 50–59 | 5087 (23.9) | 17.1 | 82.9 | 18,870 (26.4) | 18.6 | 81.4 | ||
| 60–69 | 7023 (33.0) | 16.8 | 83.2 | 21,189 (29.6) | 22.0 | 78.0 | ||
| 70–79 | 3827 (18.0) | 30.7 | 69.3 | 13,943 (19.5) | 30.6 | 69.4 | ||
| ≥ 80 | 1656 (7.8) | 45.2 | 54.8 | 4923 (6.9) | 59.4 | 40.6 | ||
| Histological subtype | ||||||||
| Ductal | 17,012 (79.9) | 22.1 | 77.9 | < 0.001 | 58,362 (81.5) | 23.9 | 76.1 | < 0.001 |
| Lobular | 2220 (10.4) | 31.7 | 68.3 | 7555 (10.6) | 36.4 | 63.6 | ||
| Other | 2046 (9.6) | 23.4 | 76.6 | 5242 (7.3) | 28.3 | 71.7 | ||
| Unknown | 10 (0.0) | 60.0 | 40.0 | 434 (0.6) | 23.0 | 77.0 | ||
| Differentiation grade | ||||||||
| I | 5355 (25.2) | 16.3 | 83.7 | < 0.001 | 18,077 (25.2) | 18.6 | 81.4 | < 0.001 |
| II | 9203 (43.2) | 24.7 | 75.3 | 32,243 (45.0) | 26.6 | 73.4 | ||
| III | 4407 (20.7) | 27.7 | 72.3 | 16,663 (23.3) | 29.7 | 70.3 | ||
| Not determined | 2046 (9.6) | 23.4 | 76.6 | – | – | – | ||
| Unknown | 277 (1.3) | 36.1 | 63.9 | 4610 (6.4) | 30.0 | 70.0 | ||
| Estrogen receptor | ||||||||
| < 10% | 3036 (14.3) | 28.3 | 71.7 | < 0.001 | 10,868 (15.2) | 29.6 | 70.4 | < 0.001 |
| ≥ 10% | 18,198 (85.5) | 22.4 | 77.6 | 59,114 (82.6) | 24.8 | 75.2 | ||
| Unknown | 54 (0.3) | 31.5 | 68.5 | 1611 (2.3) | 24.6 | 75.4 | ||
| HER2 status | ||||||||
| Negative | 18,433 (86.6) | 21.8 | 78.2 | < 0.001 | 62,047 (86.7) | 24.9 | 75.1 | < 0.001 |
| Positive | 2622 (12.3) | 32.8 | 67.2 | 8219 (11.5) | 30.5 | 69.5 | ||
| Unknown | 233 (1.1) | 33.5 | 66.5 | 1327 (1.9) | 23.7 | 76.3 | ||
| T-stage | ||||||||
| pT1 | 14,954 (70.2) | 14.5 | 85.5 | < 0.001 | 51,155 (71.5) | 18.8 | 81.2 | < 0.001 |
| pT2 | 6225 (29.2) | 43.4 | 56.6 | 20,360 (28.4) | 42.3 | 57.7 | ||
| Unknown | 109 (0.5) | 73.4 | 26.6 | 78 (0.1) | 42.3 | 57.7 | ||
| Lymph node status | ||||||||
| pN0 | 14,312 (67.2) | 17.7 | 82.3 | < 0.001 | 53,385 (74.6) | 21.7 | 78.3 | < 0.001 |
| pN1 | 6262 (29.4) | 35.1 | 64.9 | 18,089 (25.3) | 36.5 | 63.5 | ||
| Unknown | 714 (3.4) | 31.5 | 68.5 | 119 (0.2) | 51.3 | 48.7 | ||
| Hospital volume | ||||||||
| Low | 703 (3.3) | 17.8 | 82.2 | < 0.001 | 28,608 (40.0) | 30.2 | 69.8 | < 0.001 |
| Intermediate | 8689 (40.8) | 27.1 | 72.9 | 34,909 (48.8) | 22.8 | 77.2 | ||
| High | 11,896 (55.9) | 20.8 | 79.2 | 8076 (11.3) | 20.8 | 79.2 | ||
HER2 human epidermal growth factor receptor 2