Table 1 Clinicopathological characteristics of Yale cohorts
| Â | Cohort 1 | Cohort 2 | Combined |
|---|---|---|---|
Characteristic | N (%) | N (%) | N (%) |
All patients | 501 | 296 | 797 |
Age (y) | Â | Â | Â |
   <50 | 146 (29.1) | 96 (32.4) | 242 (30.4) |
   ≥50 | 355 (70.8) | 200 (67.6) | 555 (69.6) |
Nodal Status | Â | Â | Â |
   positive | 267 (53.2) | 59 (19.9) | 326 (40.9) |
   negative | 234 (46.7) | 160 (54.1) | 394 (49.4) |
   unknown | 0 (0) | 77 (26.0) | 77 (9.7) |
Tumor Size (mm) | Â | Â | Â |
   ≤2 | 155 (30.9) | 148 (50.0) | 303 (38.0) |
   2 to 5 | 251 (50.1) | 78 (26.4) | 388 (48.7) |
   ≥5 | 55 (11.0) | 4 (1.3) |  |
   unknown | 40 (8.0) | 66 (22.3) | 106 (13.3) |
ER (IHC) | Â | Â | Â |
   positive (1 to 3) | 251 (50.1) | 164 (55.4) | 415 (52.1) |
   negative (0) | 234 (46.7) | 97 (32.8) | 331 (41.5) |
   unknown | 16 (3.2) | 35 (11.8) | 51 (6.4) |
PR (IHC) | Â | Â | Â |
   positive (1 to 3) | 241 (48.1) | 33 (11.1) | 274 (34.4) |
   negative (0) | 233 (46.5) | 221 (74.7) | 454 (57.0) |
   unknown | 27 (5.4) | 42 (14.2) | 69 (8.6) |
HER2 (IHC) | Â | Â | Â |
   positive (2 to 3) | 86 (17.2) | 30 (10.1) | 116 (14.6) |
   negative (0 to 1) | 393 (78.4) | 213 (72.0) | 606 (76.0) |
   unknown | 22 (4.4) | 53 (17.9) | 75 (9.4) |
Follow-up (m) | Â | Â | Â |
   median (range) | 105.1 (2.39 to 498.03) | 120.0 (3 to 385) | 113.0 (2.4 to 250) |