Table 1.
Participant demographic and clinical characteristics at study entry (N = 1253)
| Age at breast cancer diagnosis | |
| Median (range) | 50 (27–70) |
| Race/Ethnicity N (%) | |
| White | 1060 (84.6%) |
| Black | 45 (3.6%) |
| Hispanic | 85 (6.8%) |
| Asian | 31 (2.5%) |
| Other | 32 (2.6%) |
| Stage N (%) | |
| I | 453 (36.2%) |
| IIA | 432 (34.5%) |
| IIB | 144 (11.5%) |
| IIIA | 166 (13.2%) |
| IIIC | 58 (4.6%) |
| Nodal status N (%) | |
| Negative | 702 (56%) |
| Positive | 551 (44%) |
| Tumor size (cm) | |
| Mean (SD) | 2.3 (1.44) |
| Grade N (%) | |
| Poorly differentiated | 497 (39.7%) |
| Moderately differentiated | 496 (39.6%) |
| Well differentiated | 159 (12.7%) |
| Unspecified | 101 (8.1%) |
| Histopathology N (%) | |
| ER+ | 909 (73.7%) |
| PR+ | 809 (66.4%) |
| Her2+ | 217 (17.3%) |
| Triple negative | 199 (15.9%) |
| Years diagnosis to study entry | |
| Median (25th, 75th %-iles) | 1.8 (1.03, 2.8) |
| Chemotherapy and Anti-estrogen therapy N (%) | |
| Yes, yes | 590 (47.1%) |
| Yes, no | 314 (25.1%) |
| No, yes | 258 (20.6%) |
| No, no | 76 (6.1%) |
| Yes, unknown | 5 (0.4%) |
| No, unknown | 9 (0.7%) |
| Outcomes | |
| Breast cancer events (N) | 303 |
| Disease-free survival (years) | |
| Median (25th, 75th)%-iles | 9.5 (6.7, 11.3) |
| Breast cancer deaths (N) | 219 |
| Breast cancer survival (years) | |
| Median (25th, 75th)%-iles | 16.8 (15.3, 18.2) |