Table 1 Patient, treatment, and tumor-related characteristics of all stage IV IBC patients per breast cancer subtype (n = 744)
HR+/HER2− (n = 340) | HR+/HER2+ (n = 131) | HR−/HER2+ (n = 148) | HR−/HER2− (n = 125) | p value | |
|---|---|---|---|---|---|
N (%) | N (%) | N (%) | N (%) | ||
Age, median (IQR) | 61 (52–73) | 60 (50–74) | 57.5 (50–69) | 62 (52–73) | 0.191 |
Histological grade | |||||
1 | 6 (1.8) | 2 (1.5) | 0 (0.0) | 1 (0.8) | NC |
2 | 40 (11.8) | 13 (9.9) | 16 (10.8) | 8 (6.4) | |
3 | 44 (12.9) | 19 (14.5) | 36 (24.3) | 37 (29.6) | |
Unknown* | 250 (73.5) | 97 (74.1) | 96 (64.9) | 79 (63.2) | |
Histological type | |||||
Ductal | 279 (82.1) | 119 (90.8) | 113 (89.9) | 110 (80.0) | 0.019 |
Lobular | 49 (14.4) | 7 (5.3) | 10 (6.7) | 8 (6.4) | |
Other | 12 (3.5) | 5 (3.8) | 5 (3.4) | 7 (5.6) | |
Metastatic sites | |||||
1 | 167 (49.1) | 54 (41.2) | 74 (50.0) | 58 (46.4) | |
2 or more | 173 (50.9) | 77 (58.8) | 74 (50.0) | 67 (53.6) | 0.414 |
Surgery | |||||
Yes | 60 (17.7) | 24 (18.3) | 40 (27.0) | 25 (20.0) | 0.113 |
No | 280 (82.4) | 107 (81.7) | 108 (73.0) | 100 (80.0) | |
ALND | |||||
Yes | 46 (13.5) | 14 (10.7) | 24 (16.2) | 18 (14.4) | 0.603 |
No | 294 (86.5) | 117 (89.3) | 124 (83.8) | 107 (85.6) | |
Chemotherapy | |||||
Yes | 166 (48.8) | 88 (67.2) | 128 (86.5) | 103 (82.4) | < 0.001 |
No | 174 (51.2) | 43 (32.8) | 20 (13.5) | 22 (17.6) | |
Endocrine therapy | |||||
Yes | 253 (74.4) | 83 (63.4) | 6 (4.1) | 2 (1.6) | < 0.001 |
No | 87 (25.6) | 48 (36.6) | 142 (96.0) | 123 (98.4) | |
Radiation therapy | |||||
Yes | 65 (19.1) | 21 (16.0) | 28 (18.9) | 31 (24.8) | 0.347 |
No | 275 (80.9) | 110 (84.0) | 120 (81.1) | 94 (75.2) | |
Anti-HER2 therapy | |||||
Yes | 21 (6.2) | 90 (68.7) | 111 (75.0) | 11 (8.8) | < 0.001 |
No | 319 (93.8) | 41 (31.3) | 37 (25.0) | 114 (91.2) | |
Trimodality therapy | |||||
Yes | 30 (8.8) | 7 (5.3) | 14 (9.5) | 9 (7.2) | 0.555 |
No | 310 (91.2) | 124 (94.7) | 134 (90.5) | 116 (92.8) | |