Table 2.
Characteristics of the study population according to mean S100A8 copy number
| Study Population | Mean S100A8 CN in the primary tumor | |||
|---|---|---|---|---|
| < 4 | ≥ 4 | p-value (χ2) | ||
| N (%) | 475 | 379 (80) | 96 (20) | |
| Mean age at diagnosis, years (SD) | 76.1 (8.2) | 76.4 (8.3) | 75.1 (7.6) | |
| Mean follow-up after diagnosis, years (SD) | 8.7 (6.8) | 8.9 (6.8) | 8.1 (6.7) | |
| Deaths from BC (%) | 171 (36) | 131 (35) | 40 (42) | |
| Deaths from other causes (%) | 255 (54) | 206 (54) | 49 (51) | |
| Grade (%) | ||||
| 1 | 48 (10) | 42 (11) | 6 (6) | < 0.001 |
| 2 | 267 (56) | 233 (61) | 34 (35) | |
| 3 | 160 (34) | 104 (27) | 56 (58) | |
| Lymph node metastasis (%) | ||||
| Yes | 165 (35) | 134 (35) | 31 (32) | 0.85 |
| No | 200 (42) | 158 (42) | 42 (44) | |
| Unknown histology | 110 (23) | 87 (23) | 23 (24) | |
| Mean S100A8 CN in lymph node metastasis (%) | ||||
| < 4 | 70 (74) | 60 (86) | 14 (58) | 0.005 |
| ≥ 4 | 24 (26) | 10 (14) | 10 (42) | |
| Molecular subtype (%) | ||||
| Luminal A | 251 (53) | 212 (56) | 39 (41) | 0.002 |
| Luminal B (HER2-) | 114 (24) | 92 (24) | 22 (23) | |
| Luminal B (HER2+) | 37 (8) | 26 (7) | 11 (11) | |
| HER2 type | 25 (5) | 17 (5) | 8 (8) | |
| 5NP | 11 (2) | 10 (3) | 1 (1) | |
| BP | 36 (8) | 21 (6) | 15 (16) | |
| Histologic subtype (%) | ||||
| Ductal (NOS) | 324 (68) | 258 (68) | 66 (69) | 0.3 |
| Lobular | 64 (13) | 55 (15) | 9 (9) | |
| Other | 87 (18) | 66 (17) | 21 (22) | |
| Ki67 high / low (%) | ||||
| Ki67 < 15% | 286 (60) | 239 (63) | 47 (49) | 0.03 |
| Ki67 ≥ 15% | 188 (40) | 139 (37) | 49 (51) | |
| Mitoses / 10 HPF, median (IQR p25, p75) | 5 (1, 12) | 4 (1, 11) | 9 (3, 17) | |
| Mitoses / 10 HPF, quartiles (%) | ||||
| ≤ 1 | 114 (27) | 100 (29) | 14 (18) | 0.003 |
| > 1, ≤ 5 | 110 (26) | 97 (28) | 13 (16) | |
| > 5, ≤ 12 | 102 (24) | 79 (23) | 23 (29) | |
| > 12 | 102 (24) | 73 (21) | 29 (37) | |
N number of patients, SD standard deviation, BC breast cancer, HER2 human epidermal growth factor receptor 2, 5NP 5 negative phenotype, BP basal phenotype, HPF high-power field, IQR interquartile range