Table 1.
Patient characteristics.
| No. (%) | ||||
|---|---|---|---|---|
| Characteristics | ASTTRA cohort (n=1282) | Breast density cohort (n=944) | P | |
| Age at enrollment, years | ||||
| <35 | 172 (13.4) | 131 (13.9) | 0.788 | |
| 35–39 | 367 (28.6) | 258 (27.3) | ||
| 40–45 | 743 (58.0) | 555 (58.8) | ||
| Lymph node status | 0.252 | |||
| Negative | 577 (45.0) | 448 (47.5) | ||
| Positive | 705 (55.0) | 496 (52.5) | ||
| Tumor size, cm | 0.499 | |||
| <2 | 617 (48.1) | 468 (49.6) | ||
| ≥2 | 665 (51.9) | 476 (50.4) | ||
| Tumor grade | 0.890 | |||
| 1 | 206 (16.1) | 146 (15.5) | ||
| 2 | 663 (51.7) | 486 (51.5) | ||
| 3 | 305 (23.8) | 224 (23.7) | ||
| Unknown | 108 (8.4) | 88 (9.3) | ||
| HER2 status | 0.423 | |||
| Negative | 776 (60.5) | 551 (58.4) | ||
| Positive | 176 (13.7) | 147 (15.6) | ||
| Unknown | 330 (25.7) | 246 (26.1) | ||
| Chemotherapy regimen | 0.889 | |||
| Anthracycline plus cyclophosphamide | 378 (29.5) | 302 (32.0) | ||
| Anthracycline plus cyclophosphamide followed by taxane | 652 (50.9) | 471 (49.9) | ||
| Anthracycline plus taxane | 58 (4.5) | 42 (4.4) | ||
| Anthracycline plus cyclophosphamide and taxane | 13 (1.0) | 9 (1.0) | ||
| Fluorouracil, anthracycline, and cyclophosphamide | 148 (11.5) | 95 (10.1) | ||
| Other taxane-based regimens | 13 (1.0) | 11 (1.2) | ||
| Other nontaxane-based regimens | 9 (0.7) | 8 (0.8) | ||
| Unknown | 11 (0.9) | 6 (0.6) | ||
| Surgery | 0.330 | |||
| Total mastectomy | 504 (39.3) | 350 (37.1) | ||
| Breast-conserving surgery | 743 (58.0) | 560 (59.3) | ||
| Unknown | 35 (2.7) | 34 (3.6) | ||
| Radiotherapy at time of enrollment | 0.401 | |||
| Done | 720 (56.2) | 547 (57.9) | ||
| Not done | 562 (43.8) | 397 (42.1) | ||
| Baseline mammographic breast density grade | NA | |||
| I | — | 17 (1.8) | ||
| II | — | 114 (12.1) | ||
| III | — | 534 (56.6) | ||
| IV | — | 279 (29.6) | ||
HER2, human epidermal growth factor receptor 2; NA, not available.