Table 1.
Distribution of patient and tumor characteristics
| All n = 910 | ||||||
|---|---|---|---|---|---|---|
| Tumor in tissue microarray, n (%) | Yes, 718 (79%) | No, 192 (21%) | ||||
| Androgen receptor (AR) expression assessable, n (%) | Yes, 671 (93%) | No, 47 (7%) | ||||
| AR negative (AR−) or AR positive (AR+), n (%) | AR− 98 (15%) | AR+ 573 (85%) | Missing AR | Missing tissue and AR | ||
| Factor | n (%) or median (IQR) | n (%) or median (IQR) | n (%) or median (IQR) | P a | n (%) or median (IQR) | n (%) or median (IQR) |
| Age at baseline, years (n = 910) | 55.4 (50.1–61.7) | 55.1 (50.1–60.3) | 54.9 (49.9–61.5) | 0.94b | 53.5 (48.4–60.8) | 58.2 (51.7–63.3) |
| Age at diagnosis, years (n = 910) | 65.0 (60.0–71.6) | 64.0 (59.8–69.4) | 65.0 (60.2–72.0) | 0.22b | 61.5 (55.7–70.1) | 66.0 (60.4–71.9) |
| ER status (n = 760) | ||||||
| Negative (≤10%) | 89 (12) | 37 (41) | 39 (7) | 5 (16) | 8 (7) | |
| Positive (>10%) | 671 (88) | 54 (59) | 489 (93) | <0.0001 | 27 (84) | 101 (93) |
| PR status (n = 689) | ||||||
| Negative (≤10%) | 311 (45) | 58 (69) | 190 (40) | 17 (59) | 46 (47) | |
| Positive (>10%) | 378 (55) | 26 (31) | 288 (60) | <0.0001 | 12 (41) | 52 (53) |
| Tumor size (n = 887) | ||||||
| >20 mm | 250 (28) | 47 (48) | 160 (28) | 9 (20) | 34 (20) | |
| ≤20 mm | 637 (72) | 51 (52) | 410 (72) | <0.0001 | 37 (80) | 139 (80) |
| ALNI (n = 819) | ||||||
| Positive (≥1 metastatic node) | 262 (32) | 39 (41) | 182 (34) | 9 (21) | 32 (23) | |
| Negative | 557 (68) | 55 (59) | 361 (66) | 0.13 | 34 (79) | 107 (77) |
| NHG (n = 835) | <0.0001c | |||||
| I | 227 (27) | 9 (9) | 158 (28) | Ref.d | 13 (32) | 47 (35) |
| II | 392 (47) | 30 (31) | 285 (51) | 0.12d | 16 (40) | 61 (46) |
| III | 216 (26) | 58 (60) | 121 (21) | <0.0001d | 11 (28) | 26 (19) |
| HER2 status (n = 593) | ||||||
| Positive (IHC/ISH) | 52 (9) | 6 (9) | 39 (9) | 2 (7) | 5 (6) | |
| Negative | 541 (91) | 64 (91) | 372 (91) | 0.81 | 28 (93) | 77 (94) |
| In ER negative PR negative only (n = 79) | ||||||
| HER2 status (n = 67) | ||||||
| Positive | 18 (27) | 2 (6) | 12 (44) | 1 (25) | 3 (60) | |
| Negative (TNBC) | 49 (73) | 29 (94) | 15 (56) | 0.0007 | 3 (75) | 2 (40) |
| Ki67 status (n = 633) | ||||||
| High (>10%) | 214 (34) | 43 (55) | 131 (30) | 13 (48) | 27 (31) | |
| Low (≤10%) | 419 (66) | 35 (45) | 309 (70) | <0.0001 | 14 (52) | 61 (69) |
| Planned adjuvant treatments | ||||||
| Endocrine therapy | ||||||
| In all patients (n = 878) | ||||||
| None | 409 (47) | 54 (56) | 213 (38) | 29 (62) | 113 (66) | |
| Any (TAM/AI) | 469 (53) | 43 (44) | 349 (62) | 0.001 | 18 (38) | 59 (34) |
| In ER+ only (n = 662) | ||||||
| None | 254 (38) | 17 (31) | 166 (35) | 13 (48) | 58 (58) | |
| Any (TAM/AI) | 408 (62) | 37 (69) | 315 (65) | 0.66 | 14 (52) | 42 (42) |
| Chemotherapy (n = 823) | ||||||
| Yes | 126 (15) | 39 (40) | 67 (13) | 5 (11) | 15 (9) | |
| No | 697 (85) | 58 (60) | 448 (87) | <0.0001 | 39 (89) | 152 (91) |
| Radiotherapy (n = 825) | ||||||
| Yes | 499 (60) | 60 (63) | 328 (63) | 23 (52) | 88 (53) | |
| No | 326 (40) | 35 (37) | 191 (37) | 0.99 | 21 (48) | 79 (47) |
| Death during follow-up (n = 256) | 256 | 34 | 144 | 16 | 62 | |
| Breast cancer underlying cause | 109 (43) | 23 (68) | 55 (38) | <0.0001 | 4 (25) | 27 (43) |
| Breast cancer contributing cause | 23 (9) | 1 (3) | 14 (10) | 0.38 | 2 (12) | 6 (10) |
| Other causes | 124 (48) | 10 (29) | 75 (52) | 0.43 | 10 (63) | 29 (47) |
AI aromatase inhibitors, ALNI axillary lymph node involvement, AR androgen receptor, CI confidence interval, df degree of freedom, ER estrogen receptor alpha, HER2 human epidermal growth factor 2 HR hazard ratio, IHC immunohistochemistry, IQR interquartile range, ISH in situ hybridization, Ki67 proliferation index, NHG Nottingham Histological Grade, PR progesterone receptor, TAM tamoxifen, TNBC triple-negative breast cancer
a Χ 2 test if not specified otherwise
bMann–Whitney U test
c Χ 2 2df
dLogistic regression model, grade I as reference